Corneal elevation changes after forced eyelid closure in healthy participants and in patients with keratoconus.

BACKGROUND: To assess pointwise corneal elevation changes after forced eyelid closure test (FECT) in the eyes of healthy subjects and in eyes with keratoconus. METHODS: Twenty-nine subjects with keratoconus and 31 healthy volunteers were evaluated. Patients with keratoconus who had corneal hydrops, apical scarring, corneal thickness ≤ 400 µm, ocular surface disease, contact lens wear on the examination day and a history of corneal cross-linking were excluded. Exclusion criteria for healthy participants were spherical error > +3.00 D and < -3.00 D, corneal astigmatism > 1.50 D, corneal curvature > 47 D, ocular allergy, clinical findings and family history of keratoconus. Pentacam was performed before and after 20 seconds of FECT and raw data were extracted from the built-in software. Pointwise anterior and posterior elevation changes in the central 8 mm cornea were assessed using paired samples t-test and heat maps were constructed to reflect mean changes and statistically significant data points. Statistical significance was assumed at p < 0.01. RESULTS: Age and gender were similar between healthy subjects (24.5 ± 1.6 years, 46.4 per cent female) and subjects with keratoconus (28.6 ± 9.2 years, 46.4 per cent female, p = 0.19, 0.61, respectively). Healthy eyes displayed posterior depression clustering in the inferotemporal and inferonasal areas (mean change: -4.5 ± 7.8 µm and -5.2 ± 9.8 µm, respectively, all p < 0.01). In contrast, keratoconus eyes exhibited a wider area of posterior elevation clustering in the inferior cornea (mean change: 8.1 ± 14.5 µm, all p < 0.01) with a small extension in the inferotemporal cornea (mean change: 12.1 ± 22.3 µm, all p < 0.01). CONCLUSION: FECT elicits corneal elevation changes mainly in the inferior cornea with the change being more pronounced and wider in eyes with keratoconus.

Quadrantwise Comparison of Lens-Iris Distance in Patients With Pseudoexfoliation Syndrome and Age-matched Controls.

PURPOSE: To perform a quadrantwise comparison of the minimum distance between the posterior iris and the anterior lens in eyes with pseudoexfoliation syndrome (PXS) and age-matched controls. PATIENTS AND METHODS: This study was designed as a prospective cross-sectional study. The study population consisted of 60 patients with PXS and 50 age-matched controls. Anterior segment Scheimpflug images of segments 90 to 270, 135 to 315, 180 to 360, and 225 to 45 degrees were exported as high-quality JPEG images (1920 pixels wide, 1048 pixels high; each pixel having a physical dimension of 8.064×8.064 µm) for further evaluation. The images were analyzed by Image J software. Minimum lens-iris distance (MLID) of the superior, inferior, nasal, and temporal quadrants were analyzed and compared between the groups. Anterior chamber depth, anterior chamber angle, pupillary diameter, average of K1 and K2 (Km), and cataract grading system by Scheimpflug imaging [Oculus Pentacam Nucleus Grading System (PNS)] were also assessed. RESULTS: The MLIDs of all quadrants in eyes with PXS were shorter than controls and these differences were statistically significant (P<0.05). The shortest distance was recorded in the inferior quadrant followed by the superior, temporal, and nasal quadrants in both groups. Pupillary diameter was the only variable found to be correlated with mean global MLID at a statistically significant level (r=-0.465, P<0.001; adjusted for age, sex, anterior chamber angle, anterior chamber depth, PNS, and Km). CONCLUSION: Eyes with PXS manifested with shorter mean MLID than controls.

A rare association of intravitreal bevacizumab injection with double ridge formation in retinopathy of prematurity.

A second anterior ridge formed 8 weeks after therapy in a case of zone II, stage 3 retinopathy of prematurity, which was treated with intravitreal bevacizumab injection alone. The clinical appearance was defined as "double ridge." Retinopathy of prematurity cases treated only with intravitreal bevacizumab injections may progress; therefore, close follow-up is recommended.