Factors affecting corneal deformation amplitude measured by Corvis ST in eyes with open-angle glaucoma.

PURPOSE: To evaluate the factors affecting corneal deformation amplitude (DA) measured using Corvis ST in eyes with open-angle glaucoma. METHODS: This prospective, longitudinal study included 48 eyes with open-angle glaucoma who required additional intraocular pressure (IOP)-lowering drops. All eyes underwent a complete eye examination at baseline, including a Corvis ST, which was repeated 4-8 weeks after the change in therapy. Factors affecting the corneal biomechanics, namely the DA, were determined using mixed effect models. RESULTS: The mean age of the cohort was 65.0 ± 7.9 years. The mean IOP reduced from 23.4 ± 5.4 mmHg to 17.9 ± 5 mmHg after the change in glaucoma treatment ( P < 0.001). The DA increased from 0.89 ± 0.16 mm to 1.00 ± 0.13 mm after IOP reduction ( P < 0.001). On mixed effect model analysis, IOP (-0.02 ± 0.001, P < 0.001) and corneal pachymetry (-0.0003 ± 0.0001, P = 0.02) affected the change in the DA. CONCLUSION: IOP and corneal pachymetry affect the DA and must be accounted for when using Corvis ST to evaluate corneal biomechanics in glaucoma.

Reference values for anterior chamber morphometrics with swept-source optical coherence tomography in a Caucasian population.

PURPOSE: The aim of this study is to generate reference values for anterior chamber morphometrics to facilitate the interpretation of anterior chamber images acquired with swept-source optical coherence tomography (SS-OCT) in a Caucasian population. MATERIALS AND METHODS: Non-glaucomatous Caucasian subjects, who were newly referred to the outpatient department of the University Eye Clinic Maastricht UMC+, were asked to undergo anterior segment assessment with SS-OCT imaging prior to routine eye examination (including visual acuity and refractive error measurements, Goldmann applanation tonometry, slit lamp examination and funduscopy). RESULTS: A total of 647 Caucasian subjects, aged 40-80 years, were included. Mean age (± standard deviation) was 61.7±10.3 years, and 294 were male (45%). Mean refractive error was -0.63±3.17 D. OCT images and measurements were obtained in all cases. The mean temporal trabecular iris angle at 500 µm (TIA500) was 27.04°±12.04°, the mean nasal TIA500 was 27.43°±11.75°, the mean anterior chamber depth (ACD) was 2.75±0.39 mm and the mean lens vault (LV) was 0.44±0.30 mm. A smaller temporal TIA500, shallower ACD and higher LV were found in female and hyperopic subjects. CONCLUSION: Reference values for anterior chamber morphometrics in Caucasians were generated, quantified and presented. These values offer tools for the interpretation of anterior segment images of Caucasians and differentiation between presumed mechanisms of angle closure.

Repeatability of vessel density measurements of optical coherence tomography angiography in normal and glaucoma eyes.

AIMS: To compare the intrasession repeatability of peripapillary and macular vessel density measurements of optical coherence tomography angiography (OCTA) in normal and glaucoma eyes, and to evaluate the effect of signal strength of OCTA scans on the repeatability. METHODS: In a cross-sectional study, three optic nerve head scans each of 65 eyes (30 normal, 35 glaucoma eyes) and three macular scans each of 69 eyes (35 normal, 34 glaucoma eyes) acquired in the same session with OCTA were analysed. Repeatability was assessed using within-subject coefficient of repeatability (CRw) and variation (CVw). Effect of signal strength index (SSI) on repeatability was evaluated with repeated-measures mixed-effects models. RESULTS: CRw (%) and CVw (%) of peripapillary measurements in normal eyes ranged between 3.3 and 7.0, and 2.5 and 4.4 respectively, and that in glaucoma eyes between 3.5 and 7.1, and 2.6 and 6.6. For the macular, these measurements ranged between 4.1 and 6.0, and 3.3 and 4.7 in normal eyes and 4.3 and 6.9, and 3.7 and 5.6 in glaucoma eyes. Repeatability estimates of most measurements were similar in normal and glaucoma eyes. Vessel densities of both peripapillary and macular regions significantly increased with increase in SSI of repeat scans (coefficients ranging from 0.15 to 0.38, p<0.01 for all associations). CONCLUSIONS: Repeatability estimates of OCTA measured peripapillary and macular vessel densities were similar in normal eyes and eyes with glaucoma. SSI values of the scans had a significant effect on the repeatability of OCTA with the vessel density values increasing in scans with higher SSI values.

Foveal Layer Morphology Detected on Spectral Domain Optical Coherence Tomography and its Correlation with Visual Acuity in Asian Indian Premature Infants in their First Year of Life.

PURPOSE: To report foveal microanatomy imaged on handheld spectral domain optical coherence tomography (SDOCT) and correlate it with visual acuity in Asian Indian premature infants. METHODS: A retrospective analysis of 32 Asian Indian premature infants, 10 with Type 2 retinopathy of prematurity (ROP), were imaged between 3 and 12 months of corrected postmenstrual age (PMA) on the handheld SDOCT (Envisu 2300, Bioptigen, DNC, USA). The foveal findings on these images were correlated with visual acuity measured using Teller acuity cards. The study cohort was divided into three groups based on the corrected age, 3-<6 months, 6-<9 months, and 9-12 months. SDOCT images of the foveal center were analyzed for inner retinal layer (IRL) persistence or fusion and presence of the external limiting membrane (ELM), inner segment-outer segment or the ellipsoid zone (EZ), and the outer segment-retinal pigment epithelium (OS-RPE) layers. RESULTS: The mean visual acuity of the three groups was 1.60, 1.63, and 1.23 logMAR, respectively (p < 0.001). Visual acuity significantly correlated with all four layers (IRL fusion, ELM, EZ, and OS-RPE in the 3-<6-month group [p < 0.001], IRL fusion only in 6-<9-month group (p < 0.001), and IRL fusion and EZ in the 9-12-month group (p < 0.001 and p = 0.01, respectively). CONCLUSIONS: The study provides insights into our understanding of a premature infant's foveal maturation in the first year. Inner retinal fusion or maturation is the most important event that correlates with better visual acuity throughout the first year. In addition, between 9 and 12 months PMA, the completion of the EZ at the foveal center positively influenced visual acuity. The presence of ROP did not influence development of the layers, but the sample size was small for subgroup analysis.

Visual Complaints and Eye Problems in Orchestral Musicians.

OBJECTIVE: To study visual complaints and eye diseases among professional and amateur orchestral musicians in the Netherlands. METHODS: In this observational study, members from professional and amateur symphony or wind orchestras were asked to complete a questionnaire collecting demographic data, musical, medical, and family history, and data on present visual complaints and/or eye diseases. Questions about playing in the orchestra were also asked. RESULTS: Data from 70 professionals and 48 amateurs showed that most musicians needed glasses or contact lenses for playing in the orchestra (61% of the professionals, 63% of the amateurs). A majority (66% of professionals, 71% of amateurs) had visited an ophthalmologist at least once during their lifetime, and 10% of the professionals and 23% of the amateurs were currently under treatment of an ophthalmologist. Visual complaints while playing in the orchestra were quite common and included poor lighting conditions, problems with reading small notes, blurred vision, tired eyes, and itching or burning eyes. Professional musicians especially reported adverse effects of eye complaints encountered in the orchestra for daily life; 35% got tired earlier and 33% felt that they could not adequately perform their tasks in the orchestra. CONCLUSION: The results show that visual complaints and eye problems probably are quite common among orchestral musicians and therefore warrant further interest and research.