Evaluation of clinical validity of the Rabin cone contrast test in normal phakic or pseudophakic eyes and severely dichromatic eyes.

PURPOSE: To evaluate the clinical validity of the Rabin cone contrast test (RCCT; Innova Systems, Inc.) in patients with normal phakic/pseudophakic eyes and severe dichromatic colour vision deficiency (CVD). METHODS: We evaluated age-related changes in the RCCT scores in 166 phakic eyes and 34 pseudophakic eyes and the RCCT sensitivity and specificity in 28 men with severe dichromatic CVD (10 with protanopia, 18 with deutanopia) and nine age-matched controls. All participants had 20/20 or better Snellen best-corrected visual acuity (BCVA). The RCCT was used to measure the L, M and S-CCT scores (range, 0-100). RESULTS: In normal phakic eyes, the mean L, M and S-CCT scores decreased gradually with ageing, with normal levels in patients in the second to seventh decades of life and some below normal in the eighth and ninth decades of life. In normal pseudophakic eyes, the mean L, M and S-CCT scores were normal in patients in the seventh to ninth decades of life. In eyes with severe CVD, the mean L, M and S-CCT scores were, respectively, 31.5 ± 18.3, 86.0 ± 12.6 and 98.0 ± 6.3 in patients with protanopia; 92.8 ± 10.5, 50.8 ± 19.6 and 97.8 ± 5.2 in patients with deutanopia; and 99.4 ± 1.7, 98.3 ± 5.0 and 99.4 ± 1.7 in controls. The RCCT sensitivity and specificity were 100% for diagnosing the CVD type. CONCLUSION: The RCCT can be used in non-visually impaired patients up to the seventh decade of life and after cataract surgery in elderly patients. The RCCT is available for CVD screening and typing and the score has a wide distribution range even in patients with severe CVD.

Capillary Dropout at the Retinal Nerve Fiber Layer Defect in Glaucoma: An Optical Coherence Tomography Angiography Study.

PURPOSE: To investigate the microvasculature changes of retinal nerve fiber layer (RNFL) defects in glaucoma. DESIGN: The study design is a case report. PATIENTS AND METHODS: Four glaucomatous eyes were included in this observational cross-sectional study. The microvasculature changes of RNFL defects were examined using optical coherence tomography (OCT) angiography. RESULTS: Three eyes had apparent wedge-shaped capillary dropout on OCT angiography. In the fourth eye, detection of wedge-shaped capillary loss was difficult because of overall capillary drop out due to advanced glaucoma. Capillary dropout detection by OCT angiography was correlated with visual field loss and RNFL defect detection by regular OCT. Compared with regular OCT used to obtain retinal thickness maps, OCT angiography is often better at visualizing the borders of lesions in the RNFL. CONCLUSIONS: OCT angiography can detect capillary dropout in RNFL defects in glaucomatous eyes, and therefore could be a useful glaucoma examination tool.

Ranibizumab and Aflibercept: Intraocular Pharmacokinetics and Their Effects on Aqueous VEGF Level in Vitrectomized and Nonvitrectomized Macaque Eyes.

PURPOSE: We evaluated the pharmacokinetics of intravitreally injected ranibizumab and aflibercept, and their effects on VEGF in the aqueous humor of vitrectomized and nonvitrectomized macaque eyes. METHODS: Intravitreal ranibizumab (IVR; 0.5 mg/50 µL) or intravitreal aflibercept (IVA; 2 mg/50 µL) was injected into the previously vitrectomized right eyes of three macaques and nonvitrectomized right eyes of three macaques. The left eyes served as controls (nonvitrectomized, noninjected). Aqueous humor was obtained from both eyes just before injection and on days 1 and 3, and weeks 1 to 8 after IVR and IVA. The ranibizumab, aflibercept, and VEGF concentrations were measured using enzyme-linked immunosorbent assays. RESULTS: The half-lives in aqueous humor of nonvitrectomized and vitrectomized eyes were, respectively, 2.3 and 1.4 days for ranibizumab, and 2.2 and 1.5 days for aflibercept. Concentration of VEGF was decreased below the limit of detection (LOD) by IVR for 3 weeks in nonvitrectomized eyes and 1 week in vitrectomized eyes, respectively, and by IVA for 6 weeks in nonvitrectomized eyes and 4 weeks in vitrectomized eyes, respectively. In the untreated control eyes, the ranibizumab and aflibercept concentrations were below the LOD, and the VEGF aqueous concentrations remained unchanged after IVR and decreased for 3 days after IVA. CONCLUSIONS: Intravitreally injected ranibizumab and aflibercept have similar half-lives in aqueous humor and shorter half-lives in vitrectomized eyes. Compared to IVR, IVA suppresses VEGF level for a longer time period.

Evaluation of acquired color vision deficiency in glaucoma using the Rabin cone contrast test.

PURPOSE: To evaluate acquired color vision deficiency in glaucoma by using the Rabin cone contrast test (RCCT). METHODS: Twenty-seven eyes of 27 patients with glaucoma (glaucoma group) and 27 eyes of 27 normal subjects (control group) were included in this study. Long (L), medium (M), and short (S) CCT scores (L CCTs, M CCTs, and S CCTs, respectively) were measured using the RCCT in both groups. Visual field examinations were performed with Humphrey automated perimetry using the Swedish interactive thresholding algorithm 30-2, and the mean deviation (MD) was evaluated. The macular ganglion cell/inner plexiform layer (GCIPL) thickness was measured using high-definition optical coherence tomography in the glaucoma group. RESULTS: The mean M CCTs and S CCTs in the glaucoma group were significantly lower (P<0.05 for both comparisons) than in the control group (M CCTs, 80.7±16.8 vs. 91.9±8.22; S CCTs, 83.9±19.5 vs. 97.4±3.77, respectively); the L CCTs did not differ significantly (P=0.065) from those of the controls (91.8±12.8 vs. 97.4±3.50, respectively). The M CCTs and S CCTs were correlated significantly with those of MD (M CCTs, r=0.47; S CCTs, r=0.44; P<0.05 for both comparisons) and GCIPL thickness (M CCTs, r=0.70; P<0.0001; S CCTs, r=0.57; P<0.01). CONCLUSIONS: The chromatic discrimination thresholds measured by RCCT in the glaucoma group were significantly different from those measured in the control group and were correlated with the MD and GCIPL thickness. The RCCT may be useful for evaluating acquired color vision deficiency in glaucoma and may help advance current understanding of the pathophysiology of glaucomatous damage.

Comparison between one injection and three monthly injections of intravitreal bevacizumab for myopic choroidal neovascularization.

AIM: To compare the effects of one intravitreal bevacizumab (IVB) injection with three monthly injections for myopic choroidal neovascularization. METHODS: Group A included 13 patients treated with one IVB injection; group B included 19 patients treated with three monthly 1.25-mg IVB injections. All patients were followed monthly for 12 months with additional injections performed as needed. The best-corrected visual acuity (BCVA) and the central foveal thickness (CFT) on optical coherence tomography were evaluated before and after treatment. RESULTS: The mean logMAR BCVA improved from 0.59 to 0.49 at 12 months in group A (p = 0.21) and from 0.65 to 0.29 in group B (p < 0.001); the improved logMAR BCVA differed significantly between the groups (p < 0.05). The mean CFT decreased from 231 µm at baseline to 150 µm at 12 months in group A (p < 0.05) and from 279 to 156 µm in group B (p < 0.001). During the follow-up, 6 of 13 eyes in group A and 5 of 19 eyes in group B received additional injections. CONCLUSIONS: Treatment starting with three monthly IVB injections may achieve better functional outcomes with fewer retreatments compared with treatment starting with one IVB injection.