Evaluation of perioperative pachymetry of thin corneas during corneal crosslinking using hypo-osmolar riboflavin and hydroxypropyl methylcellulose

ABSTRACT Purpose: This study aimed to analyze variations in intraoperative corneal thickness during corneal cross-linking in patients with keratoconus and to investigate its possible correlation with presurgical maximal keratometry (Kmax) and pachymetry. Methods: This was a prospective case series. We used a method similar to the Dresden protocol, with the application of hydroxypropyl methylcellulose 0.1% hypo-osmolar riboflavin in corneas between 330 and 400 µm after epithelium removal. Corneal thickness was measured using portable calipers before and immediately after epithelium removal, and 30 and 60 min after the procedure. Results: The 30 patients in this study were followed up for one year. A statistically significant difference was observed in pachymetry values during the intraoperative period (p<0.0001) and an increase of 3.05 µm (95%C1: 0.56-5.54) for each diopter was seen after epithelium removal (p0.019). We found an average Kmax difference of —2.12 D between men and women (p0.013). One year after treatment, there was a statistically significant reduction in pachymetry (p<0.0001) and Kmax (p0.0170) values. Conclusions: A significant increase in pachymetry measurements was seen during the procedure, and most patients showed a regression in Kmax and pachymetry values one year after surgery.

Impact of pterygium on central corneal thickness measured by optical coherence tomography in older adults.

PURPOSE: To measure the central corneal thickness (CCT) using anterior segment optical coherence tomography (AS-OCT) in older adults with and without pterygium from the Brazilian Amazon Region Eye Survey (BARES). METHODS: BARES is a population-based epidemiological cross-sectional study conducted in Parintins city. Participants were residents ≥45 years of age identified through a door-to-door interview. Eligible participants were invited for a comprehensive eye exam. Pterygium occurrence and severity were assessed by ophthalmologists through slit-lamp examination considering its location (nasal or/and temporal) and severity (lesion with extension <3 mm, ≥3 mm not reaching the pupillary margin or ≥3 mm reaching the pupillary margin). CCTs were obtained and measurements from the more severely affected eye were included. Images were analyzed offline by masked observers. RESULTS: A total of 671 subjects, 533 (79.4%) with pterygium in at least one eye and 138 (20.6%) without pterygium in either eye, were examined. The mean CCT evaluated by multiple linear regression and adjusted for demographic variables and pterygium severity was 521 ± 34 µm (median = 521; range = 304-665). Decreased CCT was significantly associated with age and pterygium severity. Individuals aged 65-74 years had CCT 7 µm thinner than those aged 45-54 years (p = 0.044), individuals aged 75 years and older had CCT 15 µm thinner than those aged 45-54 years (p = 0.001), and eyes with severe pterygium had CCT 33 µm thinner than eyes without pterygium (p < 0.001). CONCLUSIONS: The CCT analysis in this population-based sample shows that a thinner cornea is associated with pterygium severity and older age.

Correction methods for noncontact intraocular pressure measurement in patients with keratoconus and healthy individuals / Métodos de correção para medição sem contato da pressão intraocular em indivíduos normais e com ceratocone

ABSTRACT Purpose: The objective of this study was to investigate the usefulness of four different algorithms to correct noncontact intraocular pressure measurement errors in keratoconus patients and normal individuals. Methods: Noncorrected intraocular pressure and corrected intraocular pressures were measured in one eye of 34 patients with keratoconus and 34 age- and gender-matched healthy controls using Corvis Scheimpflug Technology. The correlation of noncorrected intraocular pressure and corrected intraocular pressures with age, axial length, corneal shape, thickness, and biomechanics was calculated. Corrected intraocular pressures were compared with noncorrected intraocular pressure using paired t test and Bland-Altman plots (95% limits of agreement). Results: The noncorrected intraocular pressure correlated with corneal thickness and biomechanical parameters in both groups (all p≤0.047), and front and back mean keratometry in the keratoconus group (r=-0.39, p=0.02, and r=0.39, p=0.02, respectively). After adjustment with different intraocular pressure correction algorithms, biomechanically corrected intraocular pressure showed a minimal correlation with corneal features and a nonsignificant difference with noncorrected intraocular pressure in the healthy group (-0.1 ± 1.1 mmHg, p=0.58; 95% limits of agreement: -2.3 to 2.1 mmHg). Conclusions: Measuring intraocular pressure using noncontact tonometry and its corrected forms with a corneal thickness-based simple linear formula in patients with keratoconus is associated with many errors. Using more complex formulas that take into consideration more corneal stiffness parameters in addition to corneal thickness, such as biomechanically corrected intraocular pressure formula, may be more reliable and beneficial in this group of patients.

RESUMO Objetivo: Investigar a utilidade de quatro algoritmos diferentes para corrigir erros de medição sem contato da pressão intraocular em pacientes saudáveis e com ceratocone. Métodos: A pressão intraocular não corrigida e as pressões intraoculares corrigidas foram medidas em um olho de 34 pacientes com ceratocone e 34 pacientes do grupo controle saudável pareados por idade e gênero usando a tecnologia Corvis Scheimpflug. Foi calculada a correlação da pressão intraocular não corrigida e das pressões intraoculares corrigidas com idade, comprimento axial e formato, espessura e biomecânica da córnea. As pressões intraoculares corrigidas foram comparadas com a pressão intraocular não corrigida usando o teste t pareado, e gráficos de Bland-Altman (limites de concordância de 95%). Resultados: A pressão intraocular não corrigida correlacionou-se com a espessura da córnea e com os parâmetros biomecânicos em ambos os grupos (todos p≤0,047) e a ceratometria média frontal e posterior no grupo com ceratocone (r=-0,39, p=0,02, r=0,39, p=0,02, respectivamente). Após o ajuste com diferentes algoritmos de correção da pressão intraocular, a pressão intraocular corrigida biomecanicamente revelou uma correlação mínima com as características da córnea e uma diferença não significativa com a pressão intraocular não corrigida no grupo saudável (-0,1 ± 1,1 mmHg, p=0,58; limites de concordância de 95%: -2,3 a 2,1 mmHg). Conclusões: A medição da pressão intraocular usando tonometria sem contato e suas formas corrigidas usando fórmulas lineares, simples, baseadas na espessura da córnea em pacientes com ceratocone estão associadas a muitos erros. O uso de fórmulas mais complexas que consideram mais parâmetros de rigidez da córnea além da espessura da córnea, como fórmula de pressão intraocular corrigida biomecanicamente, pode ser mais confiável e benéfico neste grupo de pacientes.

Correlations of Immediate Corneal Tomography Changes with Preoperative and the Elapsed Phaco Parameters.

Purpose: The ability to predict corneal edema and understand its relationship with imaging parameters enables optimization of decision-making in terms of cataract surgery. Therefore, we aimed to elucidate the immediate tomographic alterations after phacoemulsification. Patients and Methods: In this prospective study, we evaluated clinical and corneal tomographic data of 30 patients with cataracts, obtained using a rotating Scheimpflug tomographic system before and after cataract surgery with a phacoemulsification system. Corneal thickness and volume were measured, and Pentacam Nucleus Staging, keratometry, and specular microscopy were performed preoperatively and immediately postoperatively. The Wilcoxon signed-rank test was used to compare pre-and postoperative values. We calculated the correlations between the changes in these values and multiple parameters related to phacodynamics, including "ultrasound (US) elapsed" (phaco time), "US average" (average power used), and "US absolute" (energy effectively dissipated, a product of the other two parameters). Results: There were increases in corneal volume (p<0.0001) and pachymetry (p<0.0001), and a decrease in endothelial cell count (p<0.0001) after surgery. The mean differences in pre- and postoperative specular microscopy, corneal volume, and pachymetry were -335.13±236.21 cells/mm3, 1.33±0.56 mm3, and 61.33±23.73 microns, respectively. The difference in pre-and postoperative corneal volume in patients with US elapsed ≥40 s was 0.75 mm3 greater than that in patients with US elapsed <40 s (95% confidence interval [CI]: 0.24-1.25; p=0.005); that of pachymetry in patients with US elapsed ≥40 s was 31.76 microns greater than that in patients with US elapsed <40 s (95% CI: 9.55-53.97; p=0.007). Spearman correlation revealed that, for every 1% increase in cataract density, the US average value increased by 0.31% (coef.: 0.3110; 95% CI: 0.0741-0.5490; p=0.012). Conclusion: Knowledge of Pentacam Nucleus Staging and the effect of US elapsed on differences in corneal volume and pachymetry before and after cataract surgery should be of particular value for surgeons who routinely encounter patients with hard cataracts.

Dual-Scheimpflug-Placido-disc corneal analysis in cats.

OBJECTIVE: To evaluate the corneal topography and tomography of cats using a dual Scheimpflug and Placido disc device. ANIMAL STUDIED: Sixteen mixed-breed cats (32 eyes). PROCEDURE(S): Cats were sedated using meperidine (4.3 mg/kg/IM) and xylazine (0.5 mg/kg/IM), and evaluated using the software Galilei™. Values assessed included anterior and posterior corneal curvature, total corneal power, and corneal thickness. RESULTS: Ten males and six females aged between 18 and 48 months were evaluated. The simulated keratometry (SimK) was 38.37 ± 0.83D, mean posterior keratometry -4.89 ± 0.34D, and mean total corneal power 38.04 ± 0.94D. The mean central corneal thickness (CCT) was 617.34 ± 53.38 µm with a mean thinnest point of 583.74 ± 60.60 µm. CONCLUSION: The Galilei™ examination was feasible in cats, enabling a detailed study of the cornea. To the best of our knowledge, this is the first study evaluating the corneal topography and tomography of cats using a device that integrates data from a dual Scheimpflug and Placido disc system.

Corneal structure and endothelial morphological changes after uneventful phacoemulsification in type 2 diabetic and nondiabetic patients / Alterações da estrutura e endotélio da cornea após facoemulsificação sem complicações em pacientes diabéticos tipo 2 e não diabéticos

ABSTRACT Purpose: The aim of this study was to compare corneal structure and endothelial morphological changes after uneventful phacoemulsification cataract surgery between type 2 diabetic and nondiabetic patients and to determine the preoperative and intraoperative factors that may predict greater endothelial cell density loss. Methods: Forty-five diabetic pa­tients (45 eyes) and 43 controls (43 eyes) with age-related cataract were enrolled in this prospective observational study. Corneal (thickness and volume) and anterior segment parameters were measured by Scheimpflug tomography; endothelial cell density and morphology (coefficient of variation of cell size, hexagonal cells) were recorded using noncontact specular microscopy. Patients were evaluated preoperatively and at one and six months after surgery. Univariate and multivariate linear regression analyses were performed to evaluate the relationship between demographic, clinical, ocular, and intraoperative parameters and postoperative endothelial cell density changes at six months. Results: Significant postoperative endothelial cell loss occurred one month after surgery in both groups (p<0.001), which remained stable until month 6; there were no differences between patients with and without diabetes mellitus at any time point. The mean postoperative central corneal thickness at one and six months did not change significantly from the mean preoperative value in either group (p>0.05). Multivariate linear regression analysis showed that older age (p=0.042) and higher cataract grades (p=0.001) were significantly associated with greater endothelial cell density reduction at six-month follow-up. Conclusion: This study showed that older age and denser cataracts might be associated with greater endothelial cell density reduction after cataract surgery. Other factors, such as diabetes mellitus and preoperative anterior segment parameters, did not influence postoperative changes in endothelial cell density.

RESUMO Objetivo: Comparar a estrutura da córnea e as alterações mor­fológicas endoteliais após cirurgia de catarata por facoemulsificação sem intercorrências entre pacientes com diabetes mellitus tipo 2 e não diabéticos; e determinar quais fatores pré e intra-operatórios relacionados com a maior redução da densidade celular endotelial. Métodos: Quarenta e cinco diabéticos (45 olhos) e 43 (43 olhos) controlos com catarata relacionada à idade foram incluídos neste estudo observacional prospectivo. Os parâmetros da córnea (espessura e volume) e do segmento anterior foram medidos pela tomografia Scheimpflug; a densidade e morfologia celular endotelial (coeficiente de variação do tamanho das células, células hexagonais) foram registrados usando microscopia especular não contato. Os pacientes foram avaliados no pré-operatório, 1 e 6 meses após a cirurgia. Foi realizada uma análise de regressão linear uni e multivariada para avaliar a relação entre os parâmetros demográficos, clínicos, oculares e intra-operatórios com a redução da densidade celular endotelial aos 6 meses. Resultados: Nos dois grupos houve uma perda significativa de células endoteliais ao 1º mês pós-ope­ratório (p<0,001), que permaneceu estável até ao 6º mês; sem diferenças estatisticas entre os grupos diabetes mellitus e não diabetes mellitus em qualquer avaliação. A espessura média da córnea no pós-operatório central aos 1 e 6 meses não mudou significativamente em relação ao valor médio pré-operatório nos dois grupos (p>0.05). A análise de regressão multivariada linear mostrou que a idade avançada (p=0.042) e os graus mais elevados de catarata (p=0.001) foram significativamente associados à maior redução densidade celular endotelial aos 6 meses de seguimento. Conclusão: Este estudo mostrou que a idade avançada e as cataratas mais densas podem predispor a uma maior redução densidade celular endotelial após a cirurgia de catarata. Outros fatores, como diabetes mellitus e parâmetros pré-operatórios do segmento anterior, não influenciaram significativamente as alterações pós-operatórias da densidade celular endotelial.

The crested caracara (Caracara plancus) eye: Morphologic observations and results of selected diagnostic tests.

PURPOSE: To provide a descriptive investigation about relevant features of the crested caracara's eye (Caracara plancus) and bony orbit, as well as provide data for ophthalmic tests. METHODS: Morphological observations and the following diagnostic tests were performed: Schirmer tear test (STT), conjunctival flora evaluation, corneal touch threshold (CTT), intraocular pressure (IOP), central corneal thickness (CCT), B-mode ocular biometry, palpebral fissure length (PFL), and corneal diameter (CD) in 19 healthy birds, plus two macerated skulls. Not all birds were used for each test. RESULTS: STT: 7.84 ± 3.05 mm/min; CTT: 2.46 ± 1.10 cm; IOP: 19.18 ± 3.07 mmHg; CCT: 0.31 ± 0.02 mm; PFL: 13.32 ± 1.06 mm; CD: 10.26 ± 2.43 mm; Axial globe length: 1.89 ± 0.06 cm; Anterior chamber depth: 0.27 ± 0.06 cm; Lens axial length: 4.55 ± 0.06 cm; Vitreous chamber depth: 1.2 ± 0.07 cm. The most frequent conjunctival bacterial isolates were Corynebacterium sp. (10/23.8%), Staphylococcus sp. (9/21.42%), Streptococcus sp. (7/16.6%), and E. coli (7/16.66%). The large lateral part of the palatine bone likely plays a role in the ventral protection of the globe against the impact of prey. Observed results are generally reflective of increased body mass compared to other Falconiformes, with values approaching those of similar sized Accipitriformes. CONCLUSIONS: These data may help veterinarians recognize peculiar morphologic features and perform a more accurate diagnosis of eye diseases of this avian species.

The effects of pharmacological accommodation and cycloplegia on axial length and choroidal thickness / Efeitos da acomodação farmacológica e da cicloplegia no comprimento axial e na espessura da coroide

ABSTRACT Purpose: To investigate the effects of pharmacological accommodation and cycloplegia on ocular measurements. Methods: Thirty-three healthy subjects [mean (±SD) age, 32.97 (±5.21) years] volunteered to participate in the study. Measurement of the axial length, macular and choroidal thickness, refractive error, and corneal topography, as well as anterior segment imaging, were performed. After these procedures, pharmacological accommodation was induced by applying pilocarpine eye drops (pilocarpine hydrochloride 2%), and the measurements were repeated. The measurements were repeated again after full cycloplegia was induced using cyclopentolate eye drops (cyclopentolate hydrochloride 1%). The correlations between the measurements were evaluated. Results: A significant increase in subfoveal choroidal thickness after applying 2% pilocarpine was identified (without the drops, 319.36 ± 90.08 µm; with pilocarpine instillation, 341.60 ± 99.19 µm; with cyclopentolate instillation, 318.36 ± 103.0 µm; p<0.001). A significant increase in the axial length was also detected (without the drops, 23.26 ± 0.83 mm; with pilocarpine instillation, 23.29 ± 0.84 mm; with cyclopentolate instillation, 23.27 ± 0.84 mm; p=0.003). Comparing pharmacological accommodation and cycloplegia revealed a significant difference in central macular thickness (with pilocarpine instillation, 262.27 ± 19.34 µm; with cyclopentolate instillation, 265.93 ± 17.91 µm; p=0.016). Pilocarpine-related miosis (p<0.001) and myopic shift (p<0.001) were more severe in blue eyes vs. brown eyes. Conclusion: Pharmacological accommodation may change ocular measurements, such as choroidal thickness and axial length. This condition should be considered when performing ocular measurements, such as intraocular lens power calculations.(AU)

RESUMO Objetivo: Investigar os efeitos da acomodação farmacológica e da cicloplegia nas medições oculares. Métodos: participaram do estudo 33 voluntários saudáveis (média de idade [± DP], 32,97 anos [± 5,21 anos]). Foram medidos o comprimento axial, a espessura macular e coroidal e o erro refrativo, bem como realizados exames de imagem da topografia corneana e do segmento anterior. Em seguida, foi induzida a acomodação farmacológica aplicando-se colírio de pilocarpina (cloridrato de pilocarpina a 2%) e as medições foram repetidas nos participantes. As mesmas medições foram repetidas depois de induzir a cicloplegia completa com colírio de ciclopentolato (cloridrato de ciclopentolato a 1%) e foram avaliadas as correlações entre as medidas. Resultados: Identificou-se aumento significativo da espessura coroidal subfoveal com o uso da pilocarpina a 2% (sem colírio, 319,36 ± 90,08 µm; com a instilação de pilocarpina, 341,60 ± 99,19 µm; com a instilação de ciclopentolato, 318,36 ± 103,0 µm; p<0,001). Detectou-se também aumento significativo do comprimento axial (sem colírio, 23,26 ± 0,83 mm; com a instilação de pilocarpina, 23,29 ± 0,84 mm; com a instilação de ciclopentolato, 23,27 ± 0,84 mm; p=0,003). Ao se comparar a acomodação farmacológica e a cicloplegia, houve diferença significativa na espessura macular central (com a instilação de pilocarpina, 262,27 ± 19,34 µm; com a instilação de ciclopentolato, 265,93 ± 17,91 µm; p=0,016). Observou-se que a miose associada à pilocarpina (p<0,001) e o desvio miópico (p<0,001) foram mais severos nos olhos azuis que nos castanhos. Conclusão: A acomodação farmacológica pode alterar medidas oculares como a espessura da coroide e o comprimento axial. Essa possibilidade deve ser levada em consideração ao se efetuarem medições oculares, tais como cálculos de potência de lentes intraoculares.(AU)

Three-year follow-up in advanced pediatric keratoconus: thin corneas may not have pachymetry properly assessed after crosslinking.

AIM: To analyze the crosslinking (CXL) effects in pediatric keratoconus, and to identify the patients' corneal characteristics whose pachymetry could not be adequately evaluated by Scheimpflug method after procedure. METHODS: Consecutive pediatric patients with progressive keratoconus underwent CXL were included. Best-corrected visual acuity (BCVA) and spheric equivalent (SE) were measured before and after CXL. After CXL, groups 1 and 2 were divided based on the posterior surface Pentacam quality specifications (QS): "OK" (Group 1) and "not OK" (Group 2). The mean (RmF and RmB) and minimum (RminF and RminB) radius of curvatures of the anterior and posterior corneal surfaces, and the thinnest pachymetry (Pmin) were measured preoperatively at 3, 6, 12, 24, and 36mo. Haze was annotated. RESULTS: Twenty-six patients (14 men, mean age 14±1.8y) and median Kmax of 59.9 D initially and 61.4 D preoperatively were treated. BCVA was not different before and 24mo after CXL. Group 2 statistically differed to group 1 in that SE was more myopic before and with no difference 24mo after CXL; RmF and RmB were steeper and Pmin was thinner pre-surgically. Group 2, in which pachymetric changes could not be adequately evaluated after surgery, presented with significant RmF flattening, a shift to hyperopia, and more haze after CXL. CONCLUSION: Patients whose pachymetry could not be adequately evaluated after CXL had steeper and thinner corneas before surgery. The predictive factors for impaired QS after CXL are RmF, RmB, and Pmin. In advanced keratoconus, alternative methods to analyze pachymetry and the posterior surface should be considered.

Effects of pupillary dilation on ocular optical biometry outcomes in pediatric patients / Efeitos da dilatação pupilar nos resultados da biometria óptica ocular em pacientes pediátricos

ABSTRACT Purpose: Pharmacological pupillary dilation is performed in comprehensive ophthalmological examinations and before biometric measurements. So far, there is no consensus regarding its impact on biometric measurements. This study's aim was to investigate the effects of pharmacological pupillary dilation on ocular biometric measurements in healthy children. Methods: This was a prospective, observational, non-randomized study of children (4-18 years of age) who were admitted for routine ophthalmological examination. Biometric measurements were performed, using a non-contact optical biometry device, both before and after pharmacological pupillary dilation with cyclopentolate hydrochloride. Intraocular lens power calculations were performed using Hill-RBF, Barrett, Olsen, Sanders-Retzlaff-Kraff/Theoretical, Holladay, and Hoffer Q formulas. Descriptive statistical analyses were also performed. The Wilcoxon signed-rank test was used to compare measurements before and after pharmacological pupillary dilation. Relationships between variables were analyzed using the Spearman-Brown rank correlation coefficient. Results: The study included 116 eyes of 58 children (mean age, 8.4 ± 0.32 years; 34 girls). Significant changes were observed after pupillary dilation, compared with before pupillary dilation, in terms of anterior chamber depth, aqueous depth, and central corneal and lens thicknesses. No significant change was observed in axial length. Intraocular lens power calculations revealed no significant changes after pupillary dilation in most formulas except for the Olsen formula. The intraocular lens power was significantly inversely correlated with axial length and anterior chamber depth. Conclusions: Pharmacological pupillary dilation in children appeared to have no impact on axial length and intraocular lens power, but caused a significant increase in anterior chamber depth. The difference in anterior chamber depth measurements before and after pupillary dilation could be related to the optical biometry device model used. These outcomes should be considered in intraocular lens power calculations performed using anterior chamber depth parameters.

RESUMO Objetivo: A dilatação pupilar farmacológica é realizada em exames oftalmológicos abrangentes e antes das medições biométricas. Até o momento, não há consenso sobre seu impacto nas medições biométricas. O objetivo deste estudo foi investigar os efeitos da dilatação pupilar nas medidas biométricas oculares em crianças saudáveis. Métodos: Estudo prospectivo, observacional e não randomizado de crianças (4-18 anos) que foram admitidas para exame oftalmológico de rotina. As medidas biométricas foram realizadas usando um dispositivo de biometria óptica sem contato, antes e após a dilatação pupilar farmacológica com cloridrato de ciclopentolato. Os cálculos de potência das lentes intraoculares foram realizados utilizando as fórmulas de Hill-RBF, Barrett, Olsen, Sanders-Retzlaff-Kraff/ Teórica, Holladay e Hoffer Q. Análises estatísticas descritivas também foram realizadas. O teste dos postos sinalizados de Wilcoxon foi usado para comparar as medidas antes e após a dilatação pupilar farmacológica. As relações entre as variáveis foram analisadas pelo coeficiente de correlação de Spearman-Brown. Resultados: O estudo incluiu 116 olhos de 58 crianças (idade média de 8,4 ± 0,32 anos; 34 meninas). Alterações significativas foram observadas após a dilatação pupilar, em termos de profundidade da câmara anterior, profundidade do humor aquoso e espessura central da córnea e do cristalino. Nenhuma mudança significativa ocorreu no comprimento axial. Os cálculos de potência da lente intraocular não revelaram alterações significativas após a dilatação pupilar na maioria das fórmulas, com exceção da fórmula Olsen. O poder da lente intraocular foi significativamente inversa correlacionada com o comprimento axial e a profundidade da câmara anterior. Conclusões: A dilatação pupilar farmacológica em crianças parece não ter impacto no comprimento axial e no poder da lente intraocular, mas causou um aumento significativo na profundidade da câmara anterior. A diferença nas medidas da profundidade da câmara anterior antes e após a dilatação pupilar pode estar relacionada ao modelo do dispositivo de biometria óptica utilizado. Tais resultados devem ser considerados nos cálculos de potência da lente intraocular realizados usando parâmetros de profundidade da câmara anterior.

Accelerated corneal cross-linking with hypo-osmolar riboflavin in thin keratoconic corneas: 2-year follow-up / Cross-linking corneano acelerado com riboflavina hiposmolar em córneas ceratocônicas finas: 2 anos de acompanhamento

ABSTRACT Purpose: This study was performed to evaluate the outcomes of accelerated corneal cross-linking in keratoconic corneas with thinnest pachymetry values of <400 µm. Methods: The study included 28 eyes of 24 patients. The uncorrected and best-corrected visual acuities (logMAR), flattest and steepest keratometric readings, central corneal thickness at the thinnest point, corneal higher-order aberrations, and contrast sensitivity were assessed before and at 1, 3, 6, 12, and 24 months after corneal cross-linking. Result: The mean best-corrected visual acuity and contrast sensitivity increased (p=0.02, p=0.03, respectively), whereas the mean uncorrected visual acuity did not significantly differ (p>0.05) at 24 months after corneal cross-linking, compared with measurements before corneal cross-linking. Although the mean flattest keratometric reading showed no significant change (p=0.58), the mean steepest keratometric reading was reduced when compared with its value before corneal cross-linking (p=0.001). No change was observed in the mean central corneal thickness at the thinnest point at 24 months after corneal cross-linking, compared with its value before corneal cross-linking (p=0.12). Conclusion: Accelerated corneal cross-linking in keratoconic eyes with thin corneas could halt the progression of keratoconus in corneas thinner than 400 µm at 24 months after treatment.

RESUMO Objetivo: Este estudo foi realizado para avaliar os resultados do cross-linking corneano acelerado em córneas ceratocônicas com os valores mais baixos de paquimetria <400 µm. Métodos: O estudo incluiu 28 olhos de 24 pacientes. As acuidades visuais não corrigidas e melhor corrigidas (logMAR), leituras ceratométricas mais planas e íngremes, espessura corneana central no ponto mais fino, aberrações corneanas de mais alta ordem e a sensibilidade ao contraste foram avaliadas antes e em 1, 3, 6, 12 e 24 meses após a realização do do cross-linking. Resultados: A média da acuidade visual melhor corrigida e a sensibilidade ao contraste aumentaram (p=0,02, p=0,03, respectivamente), enquanto a média da acuidade visual não corrigida não diferiu significativamente (p>0,05) aos 24 meses após o cross-linking, comparada com medidas antes do procedimento. Embora a leitura da média da ceratometria mais plana não tenha apresentado alteração significativa (p=0,58), a leitura ceratométrica mais íngreme diminuiu quando comparada ao seu valor antes do cross-linking (p=0,001). Não foi observada alteração na média da espessura corneana central no ponto mais fino aos 24 meses após o cross-linking em comparação com seu valor antes do procedimento (p=0,12). Conclusão: O cross-linking corneano acelerado nos olhos ceratocônicos com córneas finas pode interromper a progressão do ceratocone nas córneas mais finas que 400 µm 24 meses após o tratamento.

Does wearing swimming goggles affect corneal morphology in keratoconic eyes? / Uso de óculos de natação afeta a morfologia da córnea em olhos ceratocônicos?

ABSTRACT Purpose: A significant transient increase in intraocular pressure in individuals wearing swimming goggles has been demonstrated in previous studies. These findings suggested that wearing swimming goggles could represent a significant risk factor for worsening of corneal parameters in patients with keratoconus who swim regularly. The aim of this study was to investigate corneal parameters in patients with keratoconus after wearing swimming goggles. Methods: Comprehensive ocular examinations were performed on 74 eyes of 37 patients with keratoconus. Measurements of the corneal front keratometry values (Kflat, Ksteep, and Kmax), central corneal thickness, corneal apex thickness, thinnest corneal thickness, corneal volume, anterior chamber volume, anterior chamber depth, and iridocorneal angle were performed in outpatient clinics using a Pentacam® Scheimpflug camera (Oculus, Wetzlar, Germany) before the patients wore swimming goggles and after they wore swimming goggles for 1, 10, and 20 min. A p-value of <0.05 was regarded as statistically significant. Results: The average values before and after wearing swimming goggles for 1, 10, and 20 min were 52.72 ± 5.36, 52.64 ± 5.52, 52.62 ± 5.38, and 52.22 ± 4.86, respectively (p=0.257). The average values before and after wearing swimming goggles for 1, 10, and 20 min were 46.01 ± 3.17, 46.09 ± 3.17, 46.06 ± 3.26, and 46.04 ± 3.17, respectively (p=0.426). The average values before and after wearing swimming goggles for 1, 10, and 20 min were 49.02 ± 3.56, 49.06 ± 3.61, 49.08 ± 3.62, and 49.07 ± 3.61, respectively (p=0.750). No other corneal parameters showed changes after wearing swimming goggles (p>0.05). However, the anterior chamber volume markedly decreased after wearing swimming goggles (p<0.001). Conclusions: These findings suggested that the short-term use of swimming goggles does not increase the risk of corneal parameter worsening in patients with keratoconus.

RESUMO Objetivo: Um aumento transitório significativo da pressão intraocular em indivíduos usando óculos de natação foi demonstrado em estudos anteriores. Esses achados sugerem que o uso de óculos de natação pode representar um fator de risco significativo para o agravamento dos parâmetros corneanos em pacientes com ceratocone que nadam regularmente. O objetivo deste estudo foi investigar os parâmetros corneanos em pacientes com ceratocone após o uso de óculos de natação. Métodos: Foram realizados exames oftalmológicos completos em 74 olhos de 37 pacientes com ceratocone. As medidas dos valores de ceratometria frontal da córnea (Kflat, Ksteep e Kmax), espessura corneana central, espessura apical da córnea, espessura corneana mais fina, volume da córnea, volume da câmara anterior, profundidade da câmara anterior e ângulo iridocorneano foram realizados em ambulatórios usando câmera Pentacam® Scheimpflug (Oculus, Wetzlar, Alemanha) antes dos pacientes usarem óculos de natação por 1, 10 e 20 min. Um valor p<0,05 foi considerado estatisticamente significativo. Resultados: Os valores médios de antes e após o uso de óculos de natação por 1, 10 e 20 min foram: 52,72 ± 5,36, 52,64 ± 5,52, 52,62 ± 5,38 e 52,22 ± 4,86, respectivamente (p=0,257). Os valores médios do (antes e após o uso de óculos de natação por 1, 10 e 20 min foram: 46,01 ± 3,17, 46,09 ± 3,17, 46,06 ± 3,26 e 46,04 ± 3,17, respectivamente (p=0,426). Os valores médios de antes e após o uso de óculos de natação por 1, 10 e 20 min foram: 49,02 ± 3,56, 49,06 ± 3,61, 49,08 ± 3,62 e 49,07 ± 3,61, respectivamente (p=0,750). Nenhum outro parâmetro da córnea apresentou alterações após o uso de óculos de natação (p>0,05). No entanto, o volume da câmara anterior diminuiu acentuadamente após o uso de óculos de natação (p<0,001). Conclusões: Esses achados sugerem que o uso de óculos de natação a curto prazo não aumenta o risco de piora dos parâmetros corneanos em pacientes com ceratocone.

Relationships between corneal biomechanics and the structural and functional parameters of glaucoma damage / Relações entre a biomecânica da córnea e os parâmetros estruturais e funcionais do dano do glaucoma

ABSTRACT Purpose: To investigate the relationships between (i) thickness of the retinal nerve fiber layer, optic nerve head topography, and visual field parameters and (ii) corneal biomechanical properties in normal controls and patients with ocular hypertension and primary open-angle glaucoma. Methods: This observational, cross-sectional study included 68 eyes with primary open-angle glaucoma, 99 eyes with ocular hypertension and 133 control eyes. Corneal biomechanical properties, optic nerve head topographic features, retinal nerve fiber layer thickness, and visual fields were assessed in all cases. Corneal biomechanical properties, retinal nerve fiber layer thicknesses, and optic nerve head topographic features were compared among the groups. The associations between structural and functional measures of glaucomatous damage and corneal biomechanical factors were also evaluated. Results: Significantly lower corneal hysteresis and corneal resistance factor values were observed in the primary open-angle glaucoma and ocular hypertension groups as compared with the control group, but there were no significant differences between the primary open-angle glaucoma and ocular hypertension groups. In the ocular hypertension group, no associations were observed between the corneal hysteresis and corneal resistance factor with values and the structural and functional parameters. In the primary open-angle glaucoma group, positive correlations were observed between the corneal hysteresis values and the global retinal nerve fiber layer thickness (p<0.01, r=0.27), mean retinal nerve fiber layer thickness (p<0.01, r=0.33), and mean deviation (p<0.01, r=0.26), and negative correlations were observed between the corneal resistance factor values, and the cup area (p<0.01, r=-0.39), cup-to-disk ratio (p=0.02, r=-0.28), linear cup-to-disk ratio (p=0.02, r=-0.28), and cup shape (p=0.03, r=-0.26). In the control group, weak correlations were detected between the corneal hysteresis and the cup area (p=0.03, r=0.19), cup-to-disk ratio (p=0.01, r=0.21), and linear cup-to-disk ratio (p=0.01, r=0.22). Conclusions: Distinct correlations were identified between the corneal hysteresis and corneal resistance factor values and the functional and structural parameters in the primary open-angle glaucoma and control groups. Corneal hysteresis and corneal resistance factor may have different roles in the pathophysiology of glaucoma.

RESUMO Objetivo: Investigar as relações entre (i) espessura da camada de fibras nervosas da retina, topografia do nervo óptico e parâmetros do campo visual e (ii) propriedades biomecânicas da córnea, em controles normais e pacientes com hiperten são ocular e glaucoma primário de ângulo aberto. Métodos: Este estudo observacional, transversal, incluiu 68 olhos com glaucoma primário de ângulo aberto, 99 olhos com hipertensão ocular e 133 olhos controle. As propriedades biomecânicas da córnea, as características topográficas da cabeça do nervo óptico, a espessura da camada de fibras nervosas da retina e os campos visuais foram avaliados em todos os casos. As propriedades biomecânicas da córnea, a espessura da camada de fibras nervosas da retina e as características topográficas da cabeça do nervo óptico foram comparadas entre os grupos. As associações entre medidas estruturais e funcionais de danos glaucomatosos e fatores biomecânicos da córnea também foram avaliadas. Resultados: Valores de histerese corneana e da resistência corneana foram significativamente menores nos grupos com glaucoma primário de ângulo aberto e hipertensão ocular em com paração ao grupo controle, mas não houve diferenças significativas entre os grupos de glaucoma primário de ângulo aberto e hipertensão ocular. No grupo com hipertensão ocular, não foram observadas associações entre histerese da córnea e o fator de resistência corneana com os valores e os parâmetros estruturais e funcionais. No grupo com glaucoma primário de ângulo aberto foram observadas correlações positivas entre os valores de histerese corneana e a espessura a camada de fibras nervosas da retina (p<0,01, r=0,27), espessura média da camada de fibras nervosas da retina (p<0,01, r=0,33) e desvio médio (p<0,01, r=0,26), e correlações negativas entre o os valores do fator de resistência da córnea e a área de escavação (p<0,01, r=-0,39), a relação escavação/disco (p=0,02, r=-0,28), a relação copo-para-disco linear (p=0,02, r=-0,28) e a forma da escavação (p=0,03, r=-0,26). No grupo controle, correlações foram detectadas entre a histerese da córnea e área de escavação (p=0,03, r=0,19), relação escavação/disco (p=0,01, r=0,21) e relação copo-para-disco linear (p=0,01, r=0,22). Conclusões: Correlações distintas foram identificadas entre histerese da córnea e os valores de resistência da córnea e os parâmetros funcionais e estruturais nos grupos de glaucoma primário de ângulo aberto e controle. A histerese da córnea e o fator de resistência da córnea podem ter diferentes papéis na fisiopatologia do glaucoma.

Reproducibility of the measurement of central corneal thickness in healthy subjects obtained with the optical low coherence reflectometry pachymeter and comparison with the ultrasonic pachymetry.

BACKGROUND: Corneal pachymetry is widely used for refractive surgery and follow up in keratoconus, accurate measurement is essential for a safe surgery. OBJECTIVE: To assess intraobserver reliability of central corneal thickness (CCT) measurements using optical low-coherence reflectometry (OLCR) technology and its agreement with ultrasonic pachymeter (US). METHOD: Randomized and prospective comparative evaluation of diagnostic technology. One randomly healthy eye of subjects was scanned three times with both devices. Intraobserver within-subject standard deviation (Sw), coefficient of variation (CVw) and intraclass correlation coefficient (ICC) were obtained for reliability analysis; for study agreement, data were analyzed using the paired-sample t test and the Bland-Altman LoA method. The mean of three scans of each equipment was used to assess the LoA. RESULTS: The study enrolled 30 eyes of 30 subjects with average age of 28.70 ± 8.06 years. For repeatability, the Sw were 3.41 and 5.96 µ, the intraobserver CVw was 2 and 4% and ICC 0.991 and 0.988, for OLCR and US respectively. The mean CCT difference between OLCR and US was 8.90 ± 9.03 µ (95% confidence interval: 5.52-2.27 µ), and the LoA was 35.40 µ. CONCLUSIONS: OLCR technology provided reliable intraobserver CCT measurements. Both pachymetry measurements may be used interchangeably with minimum calibration adjustment.

ANTECEDENTES: La paquimetría corneal es ampliamente utilizada para la cirugía refractiva y el seguimiento de pacientes con queratocono. La medición exacta es esencial para una cirugía refractiva segura. OBJETIVO: Evaluar la reproducibilidad intraobservador en la medición del grosor corneal central (GCC) utilizando reflectometría óptica de baja coherencia (OLCR) y su concordancia con la paquimetría ultrasónica. MÉTODO: Estudio prospectivo, comparativo y aleatorizado de una tecnología diagnóstica. Se midió de forma aleatorizada un ojo de cada sujeto en tres ocasiones con ambos equipos. Para el análisis de fiabilidad se obtuvieron la desviación estándar (DE) intrasujeto, el coeficiente de variación (CV) y el coeficiente de correlación intraclase (CCI). Para el estudio de concordancia se analizaron los datos usando una prueba t pareada simple, además de los límites de acuerdo de Bland-Altman (LA). Para la evaluación de los LA se utilizó el promedio de las tres mediciones de cada equipo. RESULTADOS: El estudio incluyó 30 ojos de 30 sujetos con una edad promedio de 28.70 ± 8.06 años. Para la repetibilidad, la DE intrasujeto fue de 3.41 y 5.96µ, el CV del 2 y el 4%, y el CCI de 0.991 y 0.988, para el OLCR y el paquímetro ultrasónico, respectivamente. La diferencia del GCC promedio entre el OLCR y el paquímetro ultrasónico fue de 8.90 ± 9.03µ (intervalo de confianza del 95%: 5.52-2.27µ), y el LA fue de 35.40µ. CONCLUSIONES: La tecnología de OLCR proporciona medidas del GCC intraobservador fiables. Ambas mediciones paquimétricas pueden usarse de forma intercambiable con mínimos ajustes de calibración.

Ocular abnormalities in morbid obesity / Anormalidades oculares na obesidade mórbida

ABSTRACT Purpose: Obesity is associated with eye diseases, but the underlying structural changes and pathogenic mechanisms have not been examined in detail. Here, we assessed the effects of morbid obesity on the morphometric indices of eye disease. Methods: Morbidly obese volunteers (n=101, body mass index [BMI] ³40) and healthy individuals (n=95, BMI: 18.50-24.99) were examined by Goldman applanation tonometry, pachymetry, and spectral domain optical coherence tomography. Intraocular pressure, anterior chamber depth, axial length, central corneal thickness, retinal nerve fiber layer thickness, central foveal thickness, and choroidal thickness were compared between groups. Results: Uncorrected intraocular pressure was significantly greater in the morbidly obese group than in the healthy control group (15.5 ± 2.5 vs. 14.5 ± 2.6 mmHg, p=0.009), whereas axial length, anterior chamber depth, and central corneal thickness did not differ between the groups. The mean retinal nerve fiber layer thickness at the temporal quadrant was reduced in the morbidly obese group (72.7 ± 13.6 vs. 85.05 ± 52.6 mm, p=0.024). Similarly, the mean retinal thicknesses at nasal and temporal 1500-mm locations were lower in the morbidly obese group (346.6 ± 18.2 vs. 353.7 ± 18.8 mm, p=0.008; 323.1 ± 20.3 vs. 330.0 ± 18.9 mm, p=0.001). The mean choroidal thickness was also reduced in almost all measurement locations (fovea, temporal 500 and 1000 mm, and nasal 500, 1000, and 1500 mm) of the obese group (p<0.05). Weight and BMI were negatively correlated with subfoveal choroidal thickness (r=-0.186, p=0.009; r=-0.173, p=0.015). Conclusion: Morbid obesity is associated with elevated uncorrected intraocular pressure and signs of neuropathy and retinopathy. Obesity may thus increase the risks of glaucoma and glaucomatous optic neuropathy.

RESUMO Objetivo: A obesidade está associada a doenças oulares, mas as mudanças estruturais subjacentes e os mecanismos patogênicos não foram examinados detalhadamente. Aqui avaliamos os efeitos da obesidade mórbida nos índices morfométricos da doença ocular. Métodos: Voluntários obesos mórbidos (n=101, índice de massa corporal ³40) e indivíduos saudáveis (n=95, índice de massa corporal 18,50 a 24,99) foram examinados por tonometria de aplanação de Goldman, paquimetria e tomografia de coerência óptica de domício espectral. A pressão intraocular, profundidade da câmara anterior, comprimento axial, espessura central da córnea, espessura da camada de fibras nervosas da retina, espessura foveal central e espessura da coroide foram comparadas entre os grupos. Resultados: A pressão intraocular não corrigida foi significativamente maior no grupo com obesidade mórbida do que no grupo controle saudável (15,5 ± 2,5 vs. 14,5 ± 2,6 mmHg, p=0,009), enquanto que o comprimento axial, profundidade da câmara anterior e espessura central da córnea não diferiram entre os grupos. A espessura média da camada de fibras nervosas da retina no quadrante temporal foi reduzida no grupo com obesidade mórbida (72,7 ± 13,6 vs. 85,05 ± 52,6 mm, p=0,024). Da mesma forma, a média das espesuras da retinianas nas localizações nasal e temporal de 1500 m foi menor no grupo com obesidade mórbida (346,6 ± 18,2 mm vs. 353,7 ± 18,8 mm, p=0,008; 323,1 ± 20,3 mm vs. 330,0 ± 18,9 mm, p=0,001). A espessura média da coroide também foi reduzida em quase todos os locais de mensuração (fóvea, temporal 500 e 1000 mm, nasal 500, 1000 e 1500 mm) do grupo obeso (p<0,05). Peso e índice de massa corporal foram negativamente correlacionados com a espessura da coroide subfoveal (r=-0,186, p=0,009; r=-0,173, p=0,015). Conclusão: A obesidade mórbida está associada à elevada pressão intraocular não corrigida e a sinais de neuropatia e retinopatia. A obesidade pode, assim, aumentar os riscos de glaucoma e neuropatia óptica glaucomatosa.

Comparison of intraocular pressure measurements between Icare PRO Tonometer, Goldmann Applanation Tonometer and non-contact tonometer in healthy and glaucomatous eyes / Comparação da medição da pressão intraocular entre o tonômetro Icare PRO, o tonômetro de aplanação de Goldmann e o tonômetro de não-contacto em olhos saudáveis e olhos glaucomatosos

Abstract Purpose: To validate the comparative measurements of intraocular pressure performed with IcarePRO tonometer (IPT) in relation to Goldmann applanation tonometer (GAT) and non-contact tonometer (NCT), as well as to evaluate the influence of central corneal thickness (CCT) on these values. Methods: This was a prospective and comparative study conducted during 6 months in the Department of Ophthalmology, Hospital de Braga, Portugal. The study population comprised two groups: healthy adults and adults with primary open angle glaucoma (POAG). The IOP values were obtained by the three tonometers and the order of execution was randomly selected. CCT values were obtained by ultrasonic pachymetry. Results: A total of 168 eyes (74 with diagnosis of POAG and 94 healthy) of 84 patients were included in this study. The mean IOP values obtained by IPT, GAT and NCT were 17.36±3.78 mmHg; 14.59±3.32 mmHg; and 17.04±4.01 mmHg, respectively. The comparison between IPT and NCT did not reveal statistically significant differences in the two groups studied. However, statistically significant differences were obtained between IPT and GAT values (p <0.001). The IOP values, recorded by all the tonometers, were significantly and positivily correlated with the CCT (p <0.001). Conclusion: IOP readings measured by IPT are comparable with those obtained by NCT, but higher than those obtained by the GAT. CCT values are correlated with IOP measurements with IPT, as it does in GAT and NCT, and should be always taken into consideration.

Resumo Objetivo: Validar os valores de pressão intraocular (IOP) realizados com o tonômetro IcarePRO (IPT) em relação ao tonômetro de aplanação de Goldmann (GAT) e tonômetro de sopro (NCP), assim como avaliar a influência da espessura central da córnea (CCT) nesses valores. Métodos: Estudo prospectivo e comparativo realizado durante 6 meses consecutivos no Departamento de Oftalmologia do Hospital de Braga, Portugal. A população estudada compreendeu dois grupos: adultos saudáveis e adultos com glaucoma primário de ângulo aberto (POAG). Os valores de IOP foram obtidos pelos três tonômetros e a ordem de execução foi selecionada aleatoriamente. Os valores de CCT foram obtidos por paquimetria ultrassônica. Resultados: Um total de 168 olhos (74 com diagnóstico de POAG e 94 saudáveis) de 84 pacientes foram incluídos neste estudo. Os valores médios de IOP obtidos pelo IPT, GAT e NCT foram de 17.36±3.78 mmHg; 14.59±3.32 mmHg; e 17.04±4.01 mmHg, respectivamente. A comparação entre IPT e NCT não revelou as diferenças estatisticamente significativas nos dois grupos estudados. No entanto, foram obtidas diferenças estatisticamente significativas entre os valores registados pelo IPT em comparação ao GAT (p <0.001). Os valores de IOP, medidos por todos os tonômetros, foram significativamente correlacionados com a CCT (p <0.001). Conclusão: As leituras de PIO medidas pelo IPT são comparáveis às obtidas pelo NCT, mas superiores às obtidas pelo GAT. Os valores de CCT estão correlacionados com medidas de IOP, tal como acontece com o GAT e NCT, pelo que devem ser levados em considerados.

Corneoscleral contact lenses fitting on irregular corneas after laser-assisted in situ keratomileusis / Lentes de contato corneoesclerais adaptadas em córneas irregulares após cirurgia LASIK

ABSTRACT Purpose: We aimed to describe the outcomes of corneoscleral contact lens fitting with multi-aspherical geometry designs in patients with irregular corneas after laser-assisted in situ keratomileusis (LASIK). Methods: This was a retrospective series of 18 patients (age, 26-38 years) selected from an eye clinic database. Participants were required to have unsatisfactory visual acuity with their current contact lenses or spectacles after LASIK for myopia correction. All patients were fitted with corneoscleral contact lenses designed to correct corneal surface irregularities. A diagnostic trial set was used for fitting, and assessments were performed according to a standardized methodology. Subjective comfort, visual acuity, central corneal thickness, endothelial cell count, and corneal-compensated intraocular pressure were evaluated. The follow-up period was one year. Results: Contact lens use was discontinued in 3 patients, thus leaving 24 eyes from 8 females and 7 males for analysis. The fitting characteristics were optimal in terms of lens position and movement. Statistically significant improvements were found in the best spectacle-corrected vision from before fitting to the visual acuity after fitting (p<0.001). Moreover, the patients reported high subjective comfort ratings and usage times (12.98 ± 2.3 hours/day). After one year of wear, visual acuity, subjective comfort, and usage time were maintained. No statistically significant adverse changes developed in the corneas over this period. Conclusion: Corneoscleral contact lenses with a multi-aspherical geometry design provide optimal visual acuity, improved comfort, and prolonged usage times in patients with irregular corneas after LASIK.

RESUMO Objetivo: Descrever os resultados do ajuste de lentes de contato corneoesclerais com geometria multiasférica em pacientes com córneas irregulares após cirurgia de ceratomileuse in situ assistida por laser (LASIK). Métodos: Esta foi uma série retrospectiva de 18 pacientes (idade, 26-38 anos) selecionados a partir de um banco de dados de uma clínica oftalmológica. Os participantes foram escolhidos ao manifestaram acuidade visual insatisfatória com suas lentes de contato ou óculos atuais depois de terem sido submetidos à LASIK para correção de miopia. Todos os pacientes receberam lentes de contato corneoesclerais projetadas para corrigir irregularidades na superficie da córnea. Um conjunto diagnóstico de prova foi usado para a adaptação e as avaliações foram feitas de acordo com uma metodologia padronizada. O conforto subjetivo, a acuidade visual, a espessura central da córnea, a contagem de células endoteliais e a pressão intraocular compensada da córnea foram avaliados. O período de acompanhamento foi de um ano. Resultados: O uso de lentes de contato foi descontinuado em 3 pacientes, deixando 24 olhos de 8 mulheres e 7 homens para análise. As características de adaptação foram ótimas em termos de posição e movimento da lente. Melhorias estatisticamente significativas foram encontradas na melhoria da visão corrigida por óculos antes de se ajustar a acuidade visual após a adaptação (p<0,001). Além disso, os pacientes relataram altos índices subjetivos de conforto e tempo de uso (12,98 ± 2,3 horas/dia). Após um ano de uso, a acuidade visual, o conforto subjetivo e o tempo de uso foram mantidos. Não houve alterações adversas estatisti­camente significativas nas córneas ao longo deste período. Conclusão: As lentes de contato corneoesclerais com projeto geométrico multiasférico proporcionam acuidade visual ideal, maior conforto e tempo de uso prolongado em pacientes com córneas irregulares após o LASIK.

Degeneração marginal pelúcida superior / Superior marginal pellucid degeneration

Resumo A degeneração marginal pelúcida (DMP) é uma ectasia corneana rara. Caracteriza-se por afinamento periférico, sem sinais inflamatórios, tipicamente inferior e bilateral, separado do limbo por área de espessura normal. Há protrusão da córnea acima da área de afinamento, resultando em elevado astigmatismo irregular. À topografia corneana, obtém-se a imagem característica, porém não patognomônica, em "asa de borboleta". Relata-se, nesse caso, um paciente com DMP superior - apresentação atípica da doença -destacando a importância da inclusão da DMP como hipótese diagnóstica nos casos de afinamentos corneanos periféricos não inflamatórios, que não comprometam apenas a região inferior da córnea.

Abstract Pellucid marginal corneal degeneration (PMCD) is a rare bilateral noninflammatory ectatic peripheral corneal disorder, usually involving the inferior portion of the cornea, separated from limbus by an area of normal corneal thickness. There is protrusion of the cornea above the thinning area, resulting in high irregular astigmatism. Corneal Topography shows the characteristic, but not pathognomonic, image of a "butterfly wing". A patient with superior PMCD - an atypical presentation of the disease - is presented, highlighting the importance of the inclusion of PMCD as a diagnostic hypothesis, in cases of non-inflammatory peripheral corneal thinning that does not compromise only the inferior corneal area.

Reproducibility of the measurement of central corneal thickness in healthy subjects obtained with the optical low coherence reflectometry pachymeter and comparison with the ultrasonic pachymetry. / Evaluación de la reproducibilidad en la medición del grosor corneal central con el paquímetro de reflectometría óptica de baja coherencia y comparación con el paquímetro ultrasónico en sujetos sanos

Background: Corneal pachymetry is widely used for refractive surgery and follow up in keratoconus, accurate measurement is essential for a safe surgery. Objective: To assess intraobserver reliability of central corneal thickness (CCT) measurements using optical low-coherence reflectometry (OLCR) technology and its agreement with ultrasonic pachymeter (US). Method: Randomized and prospective comparative evaluation of diagnostic technology. One randomly healthy eye of subjects was scanned three times with both devices. Intraobserver within-subject standard deviation (Sw), coefficient of variation (CVw) and intraclass correlation coefficient (ICC) were obtained for reliability analysis; for study agreement, data were analyzed using the paired-sample t test and the Bland-Altman LoA method. The mean of three scans of each equipment was used to assess the LoA. Results: The study enrolled 30 eyes of 30 subjects with average age of 28.70 ± 8.06 years. For repeatability, the Sw were 3.41 and 5.96 µ, the intraobserver CVw was 2 and 4% and ICC 0.991 and 0.988, for OLCR and US respectively. The mean CCT difference between OLCR and US was 8.90 ± 9.03 µ (95% confidence interval: 5.52-2.27 µ), and the LoA was 35.40 µ. Conclusions: OLCR technology provided reliable intraobserver CCT measurements. Both pachymetry measurements may be used interchangeably with minimum calibration adjustment.

Antecedentes: La paquimetría corneal es ampliamente utilizada para la cirugía refractiva y el seguimiento de pacientes con queratocono. La medición exacta es esencial para una cirugía refractiva segura. Objetivo: Evaluar la reproducibilidad intraobservador en la medición del grosor corneal central (GCC) utilizando reflectometría óptica de baja coherencia (OLCR) y su concordancia con la paquimetría ultrasónica. Método: Estudio prospectivo, comparativo y aleatorizado de una tecnología diagnóstica. Se midió de forma aleatorizada un ojo de cada sujeto en tres ocasiones con ambos equipos. Para el análisis de fiabilidad se obtuvieron la desviación estándar (DE) intrasujeto, el coeficiente de variación (CV) y el coeficiente de correlación intraclase (CCI). Para el estudio de concordancia se analizaron los datos usando una prueba t pareada simple, además de los límites de acuerdo de Bland-Altman (LA). Para la evaluación de los LA se utilizó el promedio de las tres mediciones de cada equipo. Resultados: El estudio incluyó 30 ojos de 30 sujetos con una edad promedio de 28.70 ± 8.06 años. Para la repetibilidad, la DE intrasujeto fue de 3.41 y 5.96 µ, el CV del 2 y el 4%, y el CCI de 0.991 y 0.988, para el OLCR y el paquímetro ultrasónico, respectivamente. La diferencia del GCC promedio entre el OLCR y el paquímetro ultrasónico fue de 8.90 ± 9.03 µ (intervalo de confianza del 95%: 5.52-2.27 µ), y el LA fue de 35.40 µ. Conclusiones: La tecnología de OLCR proporciona medidas del GCC intraobservador fiables. Ambas mediciones paquimétricas pueden usarse de forma intercambiable con mínimos ajustes de calibración.

Comportamento da pressão intraocular no tonômetro de aplanação de Goldman e pneumático durante o teste de sobrecarga hídrica / Intraocular pressure behavior in the Goldmann and pneumatic tonometer during water drinking test

Resumo Objetivo: Avaliar a concordância entre os tonômetros de aplanação de Goldman e pneumático na realização do teste de sobrecarga hídrica (TSH). Métodos: Estudo descritivo transversal composto por uma amostra de 102 olhos proveniente de um hospital particular em Goiânia (GO) entre 2013 a 2016, com avaliação das diferentes pressões intraoculares (PIO) nos tonômetros de aplanação de Goldman e pneumático quando submetidos ao TSH. Resultados: A média de idade foi de 52,17 (± 15,21) anos, sendo que60,8% dos pacientes pertenciam ao sexo feminino e 39,2% ao masculino. A média da espessura da córnea foi de 531,9(± 72,75) micra. Por regressão linear as variaveis idade e espessura da cornea central não ocorreram significancia estatistica entre os dois dispositivos analisados. Conclusão: Observou-se boa concordância nas medições entre os aparelhos de aplanação e o pneumático durante o teste de sobrecarga hídrica, porém necessita-se de novos estudos de maior impacto epidemiológico para confirmação desta assertiva.

Abstract Objective: To evaluate the consonance betweenthe Goldman and pneumática planation to nometers under the effect of the water drink test. Methods: Cross-sectional descriptive study consisting of a sample of 102 eyes from a private hospital in Goiânia (GO) from 2013 to 2015,with na evaluation of different intraocular pressures (IOP) in the Goldman and pneumatic flattening to nometers when submitted to TSH. Results: The average age was 52.17 (± 15.21) years old, 60.8% of the patients were female and 39.2% were male.The mean corneal thickness was 531.9(± 72.75) By linear regression the variables age and corneal thickness did not occur statistical significance between the two devices analyzed. Conclusion: Good agreement was observed in the measurements between the applanation devices and the tire during the water drink test, but new studies with a greater epidemiological impact were required to confirm this assertion.