Spectrum of variants associated with inherited retinal dystrophies in Northeast Mexico.

BACKGROUND: Inherited retinal dystrophies are hereditary diseases which have in common the progressive degeneration of photoreceptors. They are a group of diseases with clinical, genetic, and allelic heterogeneity. There is limited information regarding the genetic landscape of inherited retinal diseases in Mexico, therefore, the present study was conducted in the northeast region of the country. METHODS: Patients with inherited retinal dystrophies were included. A complete history, full ophthalmological and medical genetics evaluations, and genetic analysis through a targeted NGS panel for inherited retinal dystrophies comprising at least 293 genes were undertaken. RESULTS: A total of 126 patients were included. Cases were solved in 74.6% of the study's population. Retinitis pigmentosa accounted for the most found inherited retinal disease. Ninety-nine causal variants were found, being USH2A and ABCA4 the most affected genes (26 and 15 cases, respectively). CONCLUSIONS: The present study documents the most prevalent causative genes in IRDs, as USH2A, in northeastern Mexico. This contrasts with previous reports of IRDs in other zones of the country. Further studies, targeting previously unstudied populations in Mexico are important to document the genetic background of inherited retinal dystrophies in the country.

Conjunctival ultraviolet autofluorescence as a biomarker of outdoor exposure in myopia: a systematic review and meta-analysis.

Outdoor exposure is considered the primary modifiable risk factor in preventing the development of myopia. This effect is thought to be attributed to the light-induced synthesis and release of dopamine in the retina. However, until recent years, there was no objective quantifiable method available to measure the association between time spent outdoors and myopia. It is only recently that the conjunctival ultraviolet autofluorescence (CUVAF) area, serving as a biomarker for sun exposure, has begun to be utilized in numerous studies. To provide a comprehensive summary of the relevant evidence pertaining to the association between the CUVAF area and myopia across different geographic regions and age groups, a systematic review and meta-analysis were conducted. The search encompassed multiple databases, including MEDLINE, SCIENCE DIRECT, GOOGLE SCHOLAR, WEB OF SCIENCE, and SCOPUS, and utilized specific search terms such as "conjunctival ultraviolet autofluorescence", "CUVAF", "UVAF", "objective marker of ocular sun exposure", "myopia", "degenerative myopia", and "high myopia". The bibliographic research included papers published between the years 2006 and 2022. A total of 4051 records were initially identified, and after duplicates were removed, 49 articles underwent full-text review. Nine articles were included in the systematic review. These studies covered myopia and outdoor exposure across different regions (Australia, Europe and India) with a total population of 3615 individuals. They found that myopes generally had smaller CUVAF areas compared to non-myopes. The meta-analysis confirmed this, revealing statistically smaller CUVAF areas in myopic patients, with a mean difference of - 3.30 mm2 (95% CI - 5.53; - 1.06). Additionally, some studies showed a positive correlation between more outdoor exposure and larger CUVAF areas. In terms of outdoor exposure time, myopic patients reported less time outdoors than non-myopic individuals, with a mean difference of - 3.38 h/week (95% CI - 4.66; - 2.09). Overall, these findings highlight the connection between outdoor exposure, CUVAF area and myopia, with regional variations playing a significant role. The results of this meta-analysis validate CUVAF as a quantitative method to objectively measure outdoor exposure in relation with myopia development.

Multimodal and longitudinal evaluation of novel phenotype-genotype correlation of CLN3 isolated retinal degeneration in an hispanic female with heterozygous mutations c.944dup and c.1305C>G.

BACKGROUND: Inherited retinal disorders (IRDs) are a complex group of heritable diseases which are characterized by rod, cone, retinal pigment epithelium, or optic nerve dysfunction. Recently, mutations in CLN3 have also been associated with isolated IRDs. Herein, a case with heterozygous CLN3 variations that had not been previously linked to a CLN3-isolated retinal degeneration (CLN3IRD) phenotype in a Hispanic female and its multimodal imaging findings across a 10-year follow-up are presented. MATERIAL AND METHODS: An observational, prospective, case report on a hispanic female with CLN3IRD is presented. Patients underwent genetic testing and color fundus photography (CFC) and autofluorescence (FAF), fluorescein angiography (FA), Spectral domain optical coherence tomography (OCT) of the macular area, electroretinogram (ERG) and 30-2 visual field examination through automated perimetry. RESULTS: A female, aged 24, affected by CLN3IRD phenotype from c.944dup and c.1305C>G compound heterozygous variants, presented with bilateral hypopigmentary changes in the macular area of OU with that corresponded to hyporautofluorescent deposits in the macular area on FAF. An atrophic maculopathy was evident on structural OCT, and FA disclosed a symmetrical macular hyperflourescence with staining in the early and late stages in OU. Humphrey visual field testing showed a marked reduction of the central visual field in OU. Electrophysiological testing revealed an ERG with markedly decreased a and b waves in OU. In ten years follow up developed of bone spiculae in the midperipheral retina. CONCLUSIONS: We reported a patient with a novel CLN3IRD severe phenotype associated with the variants c.944dup and c.1305C>G, which had previously only been associated with JCNL.

Validation of a Semiautomatic Optical Coherence Tomography Digital Image Processing Algorithm for Estimating the Tear Meniscus Height.

Purpose: To design and validate a high-sensitivity semiautomated algorithm, based on adaptive contrast image, able to identify and quantify tear meniscus height (TMH) from optical coherence tomography (OCT) images by using digital image processing (DIP) techniques. Methods: OCT images of the lacrimal meniscus of healthy patients and with dry eye are analyzed by our algorithm, which is composed of two stages: (1) the region of interest and (2) TMH detection and measurement. The algorithm performs an adaptive contrast sequence based on morphologic operations and derivative image intensities. Trueness, repeatability, and reproducibility for TMH measurements are computed and the algorithm performance is statistically compared against the corresponding negative obtained manually by using a commercial software. Results: The algorithm showed excellent repeatability supported by an intraclass correlation coefficient equal to 0.993, a within-subject standard deviation equal to 9.88, and a coefficient of variation equal to 2.96%, and for the reproducibility test, the results did not show a significant difference as the mean value was 244.4 ± 114.9 µm for an expert observer versus 242.4 ± 111.2 µm for the inexperienced observer (P = 0.999). The method strongly suggests the algorithm can predict measurements that are manually performed with commercial software. Conclusions: The presented algorithm possess high potential to identify and measure TMH from OCT images in a reproducible and repeatable way with minimal dependency on user. Translational Relevance: The presented work shows a methodology on how, by using DIP, it is possible to process OCT images to calculate TMH and aid ophthalmologists in the diagnosis of dry eye disease.

Applications of Infrared Thermography in Ophthalmology.

Body temperature is one of the key vital signs for determining a disease's severity, as it reflects the thermal energy generated by an individual's metabolism. Since the first study on the relationship between body temperature and diseases by Carl Reinhold August Wunderlich at the end of the 19th century, various forms of thermometers have been developed to measure body temperature. Traditionally, methods for measuring temperature can be invasive, semi-invasive, and non-invasive. In recent years, great technological advances have reduced the cost of thermographic cameras, which allowed extending their use. Thermal cameras capture the infrared radiation of the electromagnetic spectrum and process the images to represent the temperature of the object under study through a range of colors, where each color and its hue indicate a previously established temperature. Currently, cameras have a sensitivity that allows them to detect changes in temperature as small as 0.01 °C. Along with its use in other areas of medicine, thermography has been used at the ocular level for more than 50 years. In healthy subjects, the literature reports that the average corneal temperature ranges from 32.9 to 36 °C. One of the possible sources of variability in normal values is age, and other possible sources of variation are gender and external temperature. In addition to the evaluation of healthy subjects, thermography has been used to evaluate its usefulness in various eye diseases, such as Graves' orbitopathy, and tear duct obstruction for orbital diseases. The ocular surface is the most studied area. Ocular surface temperature is influenced by multiple conditions, one of the most studied being dry eye; other diseases studied include allergic conjunctivitis and pterygium as well as systemic diseases such as carotid artery stenosis. Among the corneal diseases studied are keratoconus, infectious keratitis, corneal graft rejection, the use of scleral or soft contact lenses, and the response to refractive or cataract surgery. Other diseases where thermographic features have been reported are glaucoma, diabetic retinopathy, age-related macular degeneration, retinal vascular occlusions, intraocular tumors as well as scleritis, and other inflammatory eye diseases.

Clinical outcomes of the piggyback secondary implantation of a novel multifocal lens in the ciliary sulcus: A case series.

PURPOSE: Evaluate the clinical outcomes of the secondary piggyback add-on IOL implantation in the ciliary sulcus for pseudophakic patients previously implanted with a monofocal IOL, who pursue a spectacle-free option after IOL surgery. METHODS: A prospective case series including seven pseudophakic patients who underwent an in-the-bag monofocal IOL implantation. All eyes underwent a piggyback IOL implantation of the new sulcus designed A4 AddOn IOL in the ciliary sulcus as a secondary procedure for pseudophakic patients pursuing a spectacle-free option for near and intermediate distance after IOL surgery. RESULTS: Seven eyes from six patients were included in this study, from which 4 (71.43%) were female, with a mean age of 58.33 ± 3.5 years (range 54-63; 95% CI 54.66, 62.01). The postoperative spherical equivalent at the 3-month visit was -0.10 m ± 0.82. Also, the UDVA was 0.11 ± 0.08 logMAR, the UIVA 0.01 ± 0.03, and the UNVA 0.01 ± 0.03 3 months after their surgical procedure. CONCLUSIONS: The A4 AddOn multifocal IOL's secondary piggyback implant is an efficient alternative for monofocal pseudophakic patients seeking presbyopia solutions. This sulcus-designed IOL provides an optimal visual outcome for near and distance vision.

Novel RB1 germline mutation in a healthy man.

BACKGROUND: Retinoblastoma (Rb) most frequently presents as a unilateral sporadic disease up to 40% of cases, however, arise from a monoallelic germline pathogenic variant. Only 10% of the germline mutations are inherited, and high penetrance is seen in up to 90% of these cases. As an effort to optimize counseling and screening, mutations are classified according to inheritance patterns. However, RB1 spectrum is highly heterogeneous, and information for unaffected carriers remains scarce. MATERIALS AND METHODS: The Mexican family of a 5-month-old patient diagnosed with Rb was studied. The family consisted of five individuals (father, mother, and three siblings). Genetic testing using a next-generation sequencing assay targeting RB1 with oligonucleotide baits designed to capture its exons and 20 bases flanking intronic sequences was performed in every family member. Clinical history and a complete ophthalmological examination (best-corrected visual acuity, slit-lamp biomicroscopy, macular optical coherence tomography, fundus autofluorescence, optical coherence tomography angiography, and electrophysiological studies) were performed in members testing positive to RB1 mutation. RESULTS: The father and her five-month-old daughter tested positive for a non-synonymous RB1 mutation c.459del (p.Lys154Serfs*21). The girl presented with bilateral retinoblastoma, successfully treated with cryotherapy and intravenous chemotherapy. The father had no relevant findings on imaging studies or ophthalmologic evaluation. CONCLUSIONS: This report describes a rare case of a novel low-penetrance RB1 germline mutation. Long-term follow-up of the father will include periodic evaluation of the eyes and orbits, and surveillance for systemic sarcoma and secondary malignancies. Implications for unaffected individuals need to be further studied.

Agreement between the Swept-Source Optical Coherence Tomography and the Image-Guided System for Biometry Assessment in Cataract Surgery.

PURPOSE: To assess the agreement on biometric data obtained using the Verion image-guided surgery system and the swept-source-OCT biometer IOL Master 700. MATERIALS AND METHODS: All patients underwent biometry using the SS-OCT and the Image-Guide System. The comparison between instruments was assessed using the Intraclass correlation coefficient (ICC). Level of Agreement (LoA) employing the Bland-Altman analysis. RESULTS: The image-based system produced significantly higher keratometry values, evidencing a low LoA between the SS-OCT and the image-based system, ranging from -1.30 D to 0.65 D (1.95 D), -1.04 D to 0.72 D (1.76 D), and -1.31 D to 0.65 D (1.96 D), respectively. The LoA for the Cylinder ranged from -0.46 D to 0.74 D (1.2 D) and from 0.82 to 0.94 mm for WTW. CONCLUSIONS: In our study, the SS-OCT biometer and the Image-based System evidenced statistically significant differences in measuring the main biometric parameters except for the WTW.

Comparative of meibomian gland morphology in patients with evaporative dry eye disease versus non-dry eye disease.

Many recent studies have showed that morphological changes are one of the key signs of meibomian gland disease (MGD). These changes can be seen even before symptom onset, potentially underestimating the prevalence of MGD; however, until now, there is no conclusive information about the impact of meibomian gland (MG) morphology in tear film physiology and disease. This study aimed to investigate the prevalence of anatomical and morphological MG alterations between patients with evaporative dry eye disease (DED) and healthy controls. Retrospective chart review of seventy-five patients with evaporative DED and healthy individuals who had dry eye assessments included Ocular Surface Disease Index questionnaire, meibum quality, meibum expressibility, lid margin abnormality, ocular staining, non-invasive tear film break-up time, and meibography. We did not find significant differences in MG alterations in the upper lid between healthy and DED subjects. Patients with evaporative DED presented MG alterations in the lower lid more frequently than healthy subjects (54.8 vs. 30.3%; p = 0.03). The presence of shortened glands was the only MG alteration that was more prevalent in the lower lid in dry-eye patients than in healthy subjects (p < 0.05). Subjects with evaporative DED presented more alterations in the lower lid than healthy subjects.

Prevalence of Ocular Surface Disease Symptoms in High School Students in Monterrey, Mexico.

PURPOSE: To determine the prevalence of dry eye disease symptoms and contact lens wear in Mexican high school students. METHODS: A cross-sectional association study included a group of high school students who were selected from a random sampling of classrooms. The authors used the Ocular Surface Disease Index (OSDI) questionnaire as a surrogate measure for dry eye disease symptoms, and contact lens wear was also investigated. RESULTS: Seven hundred fifty-nine students with a mean age of 16.12 ± 0.96 years were surveyed and 55.7% of the students were girls (423 of 759). The average OSDI score was 25.11 ± 20.61 points. Girls had higher scores (28.25 ± 21.48 points) than boys (21.14 ± 18.74 points), and the difference was statistically significant (P < .001). Forty-three students (6.1%) wore contact lenses and had higher OSDI scores (34.26 ± 23.13 and 24.51 ± 20.31 points, respectively) and the difference was also statistically significant (P = .002). CONCLUSIONS: Symptoms of mild and moderate dry eye disease are prevalent in high school students and, as reported in previous studies, girls are more affected than boys. [J Pediatr Ophthalmol Strabismus. 2021;58(5):287-291.].

Polymicrobial Keratitis: Risk Factors, Clinical Characteristics, Bacterial Profile, and Antimicrobial Resistance.

OBJECTIVE: To describe clinical characteristics, complications, and the most prevalent microorganisms causing polymicrobial keratitis and their antibiotic sensitivities. METHODS: A cross-sectional study including a consecutive analysis of patient's records with a diagnosis of bacterial keratitis with a positive culture and antibiogram report were included. Patients were grouped into those having monomicrobial and polymicrobial infection. Features studied included demographic and clinical characteristics, risk factors, Gram stain, cultures, and antibiotic sensitivity. RESULTS: We included 656 patients; in 31.5% more than one microorganism was found. Seven hundred and twenty-three gram-positive bacteria were isolated, and 336 (46.5%) had polymicrobial keratitis. One hundred sixty-one gram-negative bacteria were isolated, and 99 (61.5%) from polymicrobial keratitis. Fourteen (0.60%) patients presented ring infiltrate, and 10 (71.42%) of those patients had polymicrobial keratitis (X2 10.654, P=0.001). Multivariate analysis showed that patients with history of contact lens use (odds ratio [OR] of 1.78, P=0.042), coexistent autoimmune disease (OR 4.64, P=0.03), irregular edges of the infiltrate (OR 2.06, P=0.005), and ring infiltrate (OR 6.034, P=0.005) have a higher risk for developing polymicrobial infection. In the polymicrobial group, gram-positive and gram-negative organisms showed a high sensitivity to Netilmicin. CONCLUSIONS: We found a high incidence of polymicrobial keratitis. Our results suggest that it should be suspected in patients with a history of contact lens use, coexistent autoimmune disease, infiltrates with indistinct edges, and ring infiltrates. Sensitivities to moxifloxacin are lower than those reported in previous studies, but sensitivity to Netilmicin is higher.

Comparative Study of Two Infrared Meibographers in Evaporative Dry Eye Versus Nondry Eye Patients.

OBJECTIVE: To compare the measurement of the meibomian gland (MG) dropout between two infrared meibographers in patients with and without dry eye. METHODS: The right eyelids of each patient were imaged using the Antares and Cobra meibography devices. All images were analyzed using Phoenix software to calculate the percentage of the MG dropout. Lipid layer thickness, eyelid margin characteristics, ocular surface staining, MG secretion, number of expressible glands, and noninvasive tear breakup time were also evaluated. A comparison between nondry eye and evaporative dry eye was performed. RESULTS: Eighty participants (mean age, 36.93 years and 51.3% women) were included, of which 67.5% had nondry eye. A significant difference was observed in the dropout percentage of the superior eyelid between the Antares and Cobra devices (P=0.007) for all participants and when only the nondry eye patients were examined. In patients with dry eye, no significant differences were found in the dropout measurements of both eyelids. CONCLUSIONS: Statistically significant differences in the MG dropout percentage in the upper eyelid of nondry eye patients were obtained from both meibographers. The measurements were similar in patients with dry eye, suggesting that the two instruments can be interchanged.

Symptoms of ocular surface disease in construction workers: comparative study with office workers.

BACKGROUND: To investigate and contrast the prevalence of dry eye symptoms in construction workers and office workers using the OSDI questionnaire. METHODS: A cross-sectional, observational study was conducted using the OSDI questionnaire to evaluate dry eye symptoms and associated risk factors. Sampled size calculation with a power of 80% and a 95% degree of confidence suggested the inclusion of 298 participants. RESULTS: We studied 304 subjects (149 construction workers and 155 office workers). More than half (55%) of the participants presented dry eye symptoms (OSDI > 12). The average OSDI score was 21.30 ± 22.20 points, being lower in the group of construction workers (12.45 ± 17.50) than in-office workers (28.51 ± 22.99) (p <  0.001). Considering participants who had moderate and severe symptoms (23 to 100 points in OSDI), office workers presented dry eye symptoms 4.15 times more frequently than construction workers (OR 4.15, 95% CI 2.52, 6.85). Women presented statistical evidence of higher OSDI scores than men (32.47 ± 23.72 vs. 14.87 ± 18.48, respectively). CONCLUSIONS: construction workers have four times less risk of presenting dry eye symptoms than people working in the average office space. This highlights the pernicious effects on the ocular surface of the office environment, which poses a significant risk for the development or worsening of dry eye symptoms.

"Novel p.Tyr284Cys BEST1 genotype-phenotype correlations of Vitelliform Macular Dystrophy in a family with incomplete penetrance".

Purpose: Vitelliform Macular Dystrophy is an inherited autosomal dominant disease with variable expressivity, caused by a mutation in the BEST1 gene. We report a family with variable expressivity and incomplete penetrance in its members.Materials and Methods: A Mexican family was studied. It was comprised of six individuals (father, mother, and four children). A clinical history was taken, and a complete ophthalmological examination (distance best-corrected visual acuity, slit-lamp biomicroscopy, optical coherence tomography, fundus autofluorescence, optical coherence tomography angiography, and electrophysiological studies) was performed in each individual.Results: Two members presented low visual acuity and vitelliform lesions in different stages in the ocular fundus. The assessment suggested a diagnosis of Vitelliform Macular Dystrophy. Genetic analysis was performed by sequencing of exons 2, 4, 5, 7, 8, and 9 of the BEST1 gene. All patients were carriers of the A variant allele of SNP rs1109748 located in exon 2 (c.219 C > A; p.Ile73=). Also, a missense mutation was identified in exon 7 in the mother and two children (c.851A>G; p.Tyr284Cys). The mother has a normal visual acuity, no abnormal findings in the ophthalmological examination and an abnormal electrooculogram, exhibiting incomplete penetrance.Conclusion: This represents one of the few cases of Vitelliform Macular Dystrophy with incomplete penetrance, being the first in our country and Latin America, and with our reported mutation with this characteristic.

Comparison of meibomian gland loss area measurements between two computer programs and intra-inter-observer agreement.

BACKGROUND: Meibography is a diagnostic test that allows in vivo evaluation of meibomian gland (MG). Nowadays, it is unknown whether the two available computer programs are equivalent to evaluate the glandular loss area. METHODS: This is a prospective, longitudinal, and observational study. A random selection of meibography photographs from healthy patients from the ocular surface clinic at Destellos de Luz foundation is made. The upper eyelid images were taken with the Antares® meibography (CSO, Florence, Italy); they were classified in five sessions with a week of separation between each measurement by an expert observer for each program, Phoenix (MAGL) and ImageJ (LAGB). An analysis of the meibomian gland loss area was performed, calculating it semiautomatically with Phoenix and manually with ImageJ. Intra-observer agreement was assessed through an intra-class correlation coefficient and the mean of standard deviations within subjects. Comparison between the two computational programs MG loss was made trough a nonparametric test. RESULTS: Fifty-four images from x patients (n, 67.3% female) were analyzed. The limits of concordance analysis between the two programs showed a range between - 18.55 and 9.14%. The mean MG loss area through ImageJ by observer 1 was 27.91 ± 14.82% (IC 95% 23.87 to 31.96), and that by observer 2 was 29.05 ± 15.17% (95% CI 24.91 to 33.19). The mean MG loss area through Phoenix by observer 1 was 24.48 ± 13.97% (IC 95% 20.67 to 28.29), and that by observer 2 was 24.93 ± 12.70% (95% CI 21.46, 28.40) CONCLUSIONS: The comparison of the measurement of meibomian gland loss with both programs showed a statistically significant difference. Intra-observer repeatability and inter-observer repeatability were good, with no clinical or statistical difference.

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.

Translation and validation of the contact lens dry eye questionnaire-8 (CLDEQ-8) to the Spanish language.

PURPOSE: To present the process of cultural and psychometric adaptation, and clinical validation of a new version in the Spanish language of the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8). MATERIALS AND METHODS: The translation-retro-translation method was applied to the CLDEQ-8 questionnaire. Two independent native Spanish-speaking translators adapted the questionnaire from English to Spanish, and then a committee of experienced clinicians (CE) evaluated the semantic equivalence and designed a Spanish version of the CLDEQ-8 questionnaire. The resulting translated version was tested conducting a pilot study in contact lens users and assessing their perception and overall understanding of the terminology. The results were analyzed and a final version was designed. The final version was retro-translated to English by a native English-speaking translator and compared with the original CLDEQ-8 version to confirm there were no meaningful differences. To clinically validate the new instrument, a prospective study was conducted to apply the new Spanish CLDEQ-8 to 50 contact lens users. RESULTS: Fifty patients were studied with an average age of 21.50 ± 1.66 years. The average CLDEQ-8 score was 13.28 ± 6.81 points (range 1-31). The internal consistency (Cronbach's alpha) was 0.89, with a corrected index of homogeneity >0.50 for all evaluated items. CONCLUSIONS: The process of trans-cultural adaptation of the questionnaire CLDEQ-8 resulted in the elaboration of a reliable and much needed instrument capable of measuring frequency and intensity of dry eye symptoms in Spanish-speaking contact lens users.

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.

Comparison of cumulative dissipated energy delivered by active-fluidic pressure control phacoemulsification system versus gravity-fluidics.

PURPOSE: To compare the cumulative dissipated energy (CDE), aspiration time and estimated aspiration fluid utilized during phacoemulsification cataract surgery using two phacoemulsification systems . METHODS: A total of 164 consecutive eyes of 164 patients undergoing cataract surgery, 82 in the active-fluidics group and 82 in the gravity-fluidics group were enrolled in this study. Cataracts graded NII to NIII using LOCS II were included. Each subject was randomly assigned to one of the two platforms with a specific configuration: the active-fluidics Centurion ® phacoemulsification system or the gravity-fluidics Infiniti ® Vision System. CDE, aspiration time (AT) and the mean estimated aspiration fluid (EAF) were registered and compared. RESULTS: A mean age of 68.3 ± 9.8 years was found (range 57-92 years), and no significant difference was evident between both groups. A positive correlation between the CDE values obtained by both platforms was verified (r = 0.271, R 2 = 0.073, P = 0.013). Similarly, a significant correlation was evidenced for the EAF (r = 0.334, R 2 = 0.112, P = 0.046) and AT values (r = 0.156, R 2 = 0.024, P = 0.161). A statistically significantly lower CDE count, aspiration time and estimated fluid were obtained using the active-fluidics configuration when compared to the gravity-fluidics configuration by 19.29, 12.10 and 9.29%, respectively (P = 0.001, P < 0.0001 and P = 0.001). CONCLUSIONS: The active-fluidics Centurion ® phacoemulsification system achieved higher surgical efficiency than the gravity-fluidics Infiniti ® IP system for NII and NIII cataracts.

Comparison of biometric measurements obtained by the Verion Image-Guided System versus the auto-refracto-keratometer.

PURPOSE: To compare the biometric measurements obtained from the Verion Image-Guided System to those obtained by auto-refracto-keratometer in normal eyes. METHODS: This is a prospective, observational, comparative study conducted at the Asociación para Evitar la Ceguera en México I.A.P., Mexico. Three sets of keratometry measurements were obtained using the image-guided system to assess the coefficient of variation, the within-subject standard deviation and intraclass correlation coefficient (ICC). A paired Student t test was used to assess statistical significance between the Verion and the auto-refracto-keratometer. A Pearson's correlation coefficient (r) was obtained for all measurements, and the level of agreement was verified using Bland-Altman plots. RESULTS: The right eyes of 73 patients were evaluated by each platform. The Verion coefficient of variation was 0.3% for the flat and steep keratometry, with the ICC being greater than 0.9 for all parameters measured. Paired t test showed statistically significant differences between groups (P = 0.0001). A good correlation was evidenced for keratometry values between platforms (r = 0.903, P = 0.0001 for K1, and r = 0.890, P = 0.0001). Bland-Altman plots showed a wide data spread for all variables. CONCLUSION: The image-guided system provided highly repeatable corneal power and keratometry measurements. However, significant differences were evidenced between the two platforms, and although values were highly correlated, they showed a wide data spread for all analysed variables; therefore, their interchangeable use for biometry assessment is not advisable.