Corneal biomechanical metrics and anterior segment parameters in mild keratoconus.

PURPOSE: To compare corneal hysteresis (CH), corneal resistance factor (CRF), spherical equivalent (SE), average central keratometry (K-Avg), corneal astigmatism (CA), corneal volume (CV), anterior chamber (AC) depth, and central corneal thickness (CCT) between patients with mild keratoconus and healthy controls and to estimate the sensitivity and specificity of CH and CRF in discriminating mild keratoconus from healthy corneas. DESIGN: Comparative case series. PARTICIPANTS: Sixty-three eyes (40 patients) with mild keratoconus (group 1) and 80 eyes from 40 gender- and age-matched controls (group 2). METHODS: Patients underwent a complete clinical eye examination, corneal topography (Humphrey ATLAS; Carl Zeiss Meditec, Dublin, CA), tomography (Pentacam; Oculus, Wetzlar, Germany), and biomechanical evaluations (ocular response analyzer; Reichert Ophthalmic Instruments, Depew, NY). The receiver operating characteristic (ROC) curve was used to identify cutoff points that maximized sensitivity and specificity in discriminating mild keratoconus from normal corneas. MAIN OUTCOME MEASURES: Corneal hysteresis, CRF, SE, K-Avg, CA, CV, AC depth, and CCT. The diagnostic performance of CH and CRF for detecting mild keratoconus was assessed using the ROC curve. RESULTS: In group 1 versus group 2, the SE values (mean+/-standard deviation) were -3.55+/-2.87 diopters (D) versus -1.46+/-3.09 D (P = 0); K-Avg, 45.09+/-2.24 versus 43.24+/-1.54 D (P = 0); CA, 3.15+/-1.87 versus 1.07+/-0.83 D (P = 0); CV, 57.3+/-2.12 versus 60.86+/-3.39 mm3 (P = 0); AC depth, 3.19+/-0.35 versus 3.05+/-0.43 mm (P = 0.0416); CCT, 503+/-34.15 versus 544.71+/-35.89 microm (P = 0); CH, 8.50+/-1.36 versus 10.17+/-1.79 mmHg (P = 0); CRF, 7.85+/-1.49 versus 10.13+/-2.0 mmHg (P = 0). The ROC curve analyses showed a poor overall predictive accuracy of CH (cutoff, 9.64 mmHg; sensitivity, 87%; specificity, 65%; test accuracy, 74.83%) and CRF (cutoff, 9.60 mmHg; sensitivity, 90.5%; specificity, 66%; test accuracy, 76.97%) for detecting mild keratoconus. CONCLUSIONS: The values for CH, CRF, CV, and CCT were statistically lower and those for SE, K-Avg, CA, and AC depth were statistically higher in patients with mild keratoconus compared with controls. Corneal hysteresis and CRF were poor parameters for discriminating between mild keratoconus and normal corneas. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Corneal biomechanical metrics in eyes with refraction of -19.00 to +9.00 D in healthy Brazilian patients.

PURPOSE: To evaluate corneal biomechanical metrics with tomographic parameters (given by the Oculus Pentacam) and refractive data in a population of healthy Brazilian patients. METHODS: Observational, cross-sectional study of 150 consecutive patients (53 men and 97 women; 260 eyes). Age, gender, central keratometric readings (central K), central corneal thickness (CCT), anterior chamber depth (ACD), spherical equivalent refraction, corneal hysteresis, and corneal resistance factor (CRF) were assessed and analyzed. RESULTS: Mean patient age was 46.5+/-21.04 years, average central K was 43.59+/-1.54 diopters (D), CCT was 545.05+/-35.41 microm, ACD was 2.96+/-0.52 mm, spherical equivalent refraction was -1.16+/-3.48 D, corneal hysteresis was 10.17+/-1.82, and CRF was 10.14+/-1.8 (range: 5.45 to 15.1). Mean CRF and corneal hysteresis were distinct among gender: CRF 10.326 in women and 9.810 in men (P=.0266); corneal hysteresis 10.421 in women and 9.727 in men (P=.0031). A negative correlation was found between both CRF and corneal hysteresis with age (r=-0.1255, P=.0434; and r=-0.2445, P=.0001, respectively). No association was found between CRF and average central K (r=0.0633, P=.3086), ACD (r=-0.0474, P=.4498), or spherical equivalent refraction (r=0.1028, P=.1061). Corneal hysteresis was not associated with age and average central K (r=0.0572, P=.3573), ACD (r=0.0060, P=.9236), or spherical equivalent refraction (r=0.0975, P=.1253). Corneal resistance factor and corneal hysteresis were positively associated with CCT (r=0.5760, P=0; and r=0.4655, P=0, respectively). CONCLUSIONS: Corneal biomechanical metrics of healthy Brazilian patients were associated with CCT, gender, and age. Corneal steepness, ACD, and spherical equivalent refraction did not affect comeal hysteresis and CRF values in the studied population.

Asymmetric vault of an accommodating intraocular lens.

We report a case of a new syndrome, late asymmetric vault of the AT45 Crystalens intraocular lens (IOL) (Eyeonics Inc.). The late vault, which occurred in 6 month after implantation of the IOL, caused a decrease in uncorrected distance and near acuities and minus-cylinder axis perpendicular to the haptics. Treatment with neodymium:YAG laser capsulotomy and fibrotic band release was successful.

Ability of corneal biomechanical metrics and anterior segment data in the differentiation of keratoconus and healthy corneas.

PURPOSE: To evaluate the sensitivity, specificity, and test accuracy of corneal biomechanical metrics and anterior segment data in differentiating keratoconus from healthy corneas. METHODS: Comparative case series. Patients with and without keratoconus (gender and age-matched) were submitted for complete eye examinations including corneal hysteresis (CH) and corneal resistance factor (CRF) as measured by the Ocular Response Analyzer and anterior segment data as gathered through Pentacam assessments. The anterior segment data measurement included average central keratometric readings (K-Ave), corneal astigmatism (CA), central corneal thickness (CCT), anterior chamber depth (AC depth) and corneal volume (CV). All parameters were assessed, compared and analyzed. A receiver operating characteristic (ROC) curve was used to identify the best cutoff point by which to maximize the sensitivity and specificity of discriminating keratoconus from normal corneas for each data category. RESULTS: Seventy seven eyes from forty three patients (24 male, 19 female) with keratoconus and eighty six eyes from forty three (24 male, 19 female) healthy controls were enrolled. ROC curve analysis showed poor overall predictive accuracy for all studied parameters in differentiating keratoconus from normal corneas. The highest sensitivity (79.2%) was obtained for both AC depth and CH (cutoff points 3.22 mm and 9.39 mmHg respectively). The best specificity (89.5%) and test accuracy (80.34%) were obtained for CA (cutoff point of 2.2 D). CONCLUSION: When considered together, studied parameters showed statistical differences between groups. However, when considered independently they presented low sensitivity, specificity and test accuracy in differentiating keratoconus from healthy corneas.

Management of unsuccessful LASIK surgery.

Refractive procedures enjoy very high success rates and are among the most commonly performed elective surgeries in medicine. With better insights into preoperative screening, the overwhelming majority of cases have successful outcomes. Unfortunately, however, all refractive surgeons must appropriately manage unsuccessful cases. Unsuccessful refractive surgery procedures may relate to each step of the refractive surgery process: preoperative screening, surgical planning, intraoperative events, and postoperative biomechanical or healing anomalies. This paper reviews the management of unsuccessful laser-assisted in situ keratomileusis (LASIK) procedures, focusing on significant advances related to wavefront-guided therapeutic ablations.

Avaliação da pressão intraocular através do ocular response analyzer antes e após cirurgia de facoemulsificação / Assessment of intraocular pressure through the ocular response analyzer before and after phacoemulsification surgery

OBJETIVO: Verificar a variação das medidas pressóricas através do Ocular Response Analyzer (ORA, Reichert): IOPg (gold standard, Goldmann correlated intraocular pressure) e IOPcc (corneal compensated intraocular pressure) antes e após a cirurgia de catarata por facoemulsificação. MÉTODOS: Estudo observacional prospectivo envolvendo 47 olhos de 36 pacientes que se submeteram à cirurgia de catarata por facoemulsificação com implante de lente intraocular. A Pressão intraocular compensada da córnea (IOPcc) e correlacionada com Goldmann (IOPg), foram medidos pelo Ocular Response Analyzer (ORA); As medidas foram realizadas no pré-operatório, 1º dia e 30º dia após a cirurgia de facoemulsificação. O Teste de Kolmogorov-Smirnov foi utilizado para avaliar a distribuição normal. Diferenças obtidas entre as medidas obtidas através do Ocular Response Analyzer foram avaliadas pelo T-test (Student's paired t-test). Foi considerado como estatisticamente significante p < 0,05 por cento. RESULTADOS: As médias da IOPcc no pré-operatório, no primeiro dia e no trigésimo dia após a cirurgia de facoemulsificação e implante de LIO foram de 15.6 (±3.06), 15.5 (±3.14) , e 15.71 (±4.34). A média de IOPg no pré-operatório foi de 14.7 (± 3.0), no primeiro dia após cirurgia 12.9 (± 3.1) e no trigésimo dia 13.4 (± 3.7). Houve diferença significativa entre IOPg (PRE X D1) com p < 0,01. CONCLUSÃO: Observamos uma diminuição da IOPg no pós-operatório imediato em córneas com edema após facoemulsificação. Logo, ressaltamos a importância da biomecânica na medida da Pio.

PURPOSE: To evaluate the IOPg (gold standard, Goldmann correlated Intraocular pressure) and IOPcc (corneal compensated Intraocular pressure) in patients prior to and following phacoemulsification with intraocular lens implantation METHODS: This is a prospective study. Thirty six consecutive patients (47 eyes) that underwent phacoemulsification surgery and intraocular lens implantation were enrolled. Full ophthalmologic clinical assessment including Ocular Response Analyzer (ORA, Reichert Ophthalmic Instruments, Buffalo, NY, USA) measurements were performed in all cases prior to surgery (Pre) and at follow-up time points: day 1 and day 30. Exclusion criteria were corneal disease or scars, previous ocular surgery and patients with glaucoma or glaucoma suspect or ocular hypertension. Student's paired t-test was utilized. RESULTS: Mean and standard-deviation of ORA parameters were: IOPcc Pre was 15.6 (±3.06), day 1 (D1) 15.5 (±3.14) and day 30 (D30) 15.71 (±4.34). The mean of IOPg was Pre 14.7 (± 3.0), day 1 (D1) 12.9 (± 3.1), and day 30 (D30) was 13.4 (± 3.7). CONCLUSION: The reduction in the IOPg was observed in the immediate postoperative underestimating the real intraocular pressure ocular. We agree that biomechanical properties may have greater impact on IOP measurements error than corneal tchikness or curvature.

Ability of corneal biomechanical metrics and anterior segment data in the differentiation of keratoconus and healthy corneas / Estudo da performance diagnóstica de parâmetros biomecânicos e dados anatômicos da câmara anterior na diferenciação de córneas saudáveis e com ceratocone

PURPOSE: To evaluate the sensitivity, specificity, and test accuracy of corneal biomechanical metrics and anterior segment data in differentiating keratoconus from healthy corneas. METHODS: Comparative case series. Patients with and without keratoconus (gender and age-matched) were submitted for complete eye examinations including corneal hysteresis (CH) and corneal resistance factor (CRF) as measured by the Ocular Response Analyzer and anterior segment data as gathered through Pentacam assessments. The anterior segment data measurement included average central keratometric readings (K-Ave), corneal astigmatism (CA), central corneal thickness (CCT), anterior chamber depth (AC depth) and corneal volume (CV). All parameters were assessed, compared and analyzed. A receiver operating characteristic (ROC) curve was used to identify the best cutoff point by which to maximize the sensitivity and specificity of discriminating keratoconus from normal corneas for each data category. RESULTS: Seventy seven eyes from forty three patients (24 male, 19 female) with keratoconus and eighty six eyes from forty three (24 male, 19 female) healthy controls were enrolled. ROC curve analysis showed poor overall predictive accuracy for all studied parameters in differentiating keratoconus from normal corneas. The highest sensitivity (79.2 percent) was obtained for both AC depth and CH (cutoff points 3.22 mm and 9.39 mmHg respectively). The best specificity (89.5 percent) and test accuracy (80.34 percent) were obtained for CA (cutoff point of 2.2 D). CONCLUSION: When considered together, studied parameters showed statistical differences between groups. However, when considered independently they presented low sensitivity, specificity and test accuracy in differentiating keratoconus from healthy corneas.

OBJETIVO: Avaliar a sensibilidade, especificidade e acurácia de parâmetros biomecânicos e anatômicos do segmento anterior isolados na diferenciação de córneas saudáveis e com ceratocone. MÉTODOS: Estudo tipo série de casos comparativa. Pacientes com ceratocone e controles saudáveis foram pareados (idade e sexo) e submetidos a exame oftalmológico completo, incluindo avaliação biomecânica (ORA) e tomográfica (Pentacam). Ceratometria central média, astigmatismo corneano, espessura corneana central, profundidade da câmara anterior, volume corneano, CH e CRF foram estabelecidos, avaliados e comparados. Curvas ROC (Receiver operating characteristic) foram utilizadas para identificar o melhor valor de corte que apresentasse a maior sensibilidade e especificidade na discriminação entre ceratocone e córneas saudáveis para cada dado estudado. RESULTADOS: Setenta e sete olhos de 43 pacientes com ceratocone (24 homens e 19 mulheres) e 86 olhos de pacientes saudáveis (24 homens e 19 mulheres) foram incluídos no estudo. Curvas ROC mostraram baixa acurácia na predição do diagnóstico de ceratocone em todos os parâmetros isolados estudados. Maior sensibilidade encontrada foi 79,2 por cento para profundidade da câmara anterior e CH (ponto de corte 3,22mm e 9,39mmHg respectivamente); maior especificidade e acurácia foram encontradas na análise do astigmatismo corneano (ponto de corte 2,2 D; 89,5 por cento e 80,34 por cento respectivamente). CONCLUSÃO: Todos os parâmetros estudados mostraram diferença estatisticamente significativa entre os grupos. No entanto, quando considerados isoladamente apresentaram baixas sensibilidade, especificidade e acurácia na diferenciação entre ceratocone e córneas saudáveis.

Allelic association study between phospholipase A2 genes and bipolar affective disorder.

OBJECTIVES: In vivo studies demonstrating that lithium is a powerful phospholipase A2 (PLA2) inhibitor suggest that PLA2 activation, and subsequent cell signaling overactivation by increased fatty acid release may be the primary abnormality in bipolar affective disorder (BPAD), thus making PLA2 genes attractive candidates for the susceptibility to BPAD. The present study investigates polymorphisms in cytosolic phospholipase A2 (cPLA2), calcium-independent phospholipase A2 (iPLA2), and secretory phospholipase (sPLA2) genes in a Brazilian sample. METHODS: A cross-sectional study was performed with 181 unrelated DSM-IIIR BPAD subjects and 312 controls. A polymerase chain reaction-restriction fragment length polymorphism assay for BanI cPLA2 and AvrII iPLA2 polymorphisms was performed, and an ATT repeat in sPLA2 was assessed using a semiautomated genetic analyzer (ALFexpress). RESULTS: There was no significant difference observed in the allelic and genotypic distribution between the BPAD and control groups for cPLA2 (genotype: chi2 = 0.8, 2df, p = 0.6; allele chi2 = 0, 1df, p = 0.9), iPLA2 (genotype: chi2 = 1.7, 2df, p = 0.4; allele: chi2 = 0.3, 1df, p = 0.6), and sPLA2 (allele: chi2 = 3.6, 6df, p = 0.8). CONCLUSION: Our results failed to demonstrate that the studied PLA2 polymorphisms were associated with an increased risk for BPAD in our sample.

Malária por Plasmodium falciparum: análise quadrienal, durante 12 anos, da eficácia do tramento com quinino / Falciparum malaria: quadrennial analysis, during 12 years of the quinine treatment eficacy

A eficácia do quinino no tratamento da malária por P. falciparum foi estudada mediante análise quadrienal de 454 prontuários de pacientes internados no HDT-GO. de 1983 a 1994, tratados somente com quinino na mesma dosagem, durante 7 dias. No quadriênio de 1983 a 1986, 98.4 por cento dos pacientes tratados näo apresentavam parasitemia assexuada já no 5§ dia de tratamento e o índice de recrudescência tardia (Rû) foi 8 por cento, de 1987 a 1990, apenas 72,9 por cento estavam sem parasitemia no 5§ dia, 1,4 por cento continuavam com parasitemia no 7§ dia (R2) e o índice de recrudescência (R1) foi 17 por cento; de 1991 a 1994, 70,3 por cento estavam sem parasitemia no 5§ dia, 3,5 por cento continuavam com parasitemia no 7§ dia (R2) e o índice de recrudescência (R1) foi 20 por cento. O aumento gradual na persistência da parasitemia, inclusive até o 7§ dia de tratamento (R2)e da recrudescência tardia (R1), indicam estar o P. falciparum desenvolvendo, na área do estudo, resistência ao quinino