Treating amblyopia in adults with prosthetic occluding contact lenses.

PURPOSE: To investigate the feasibility, effectiveness and acceptability of using prosthetic occluding contact lenses (OCLs) to treat moderate amblyopia in adults and of the role of the multifocal visual evoked potential (mfVEP) as a predictor of postamblyopic therapy. METHODS: A comparative, prospective, interventional, case series pilot study with amblyopic adults (mean age: 40 years, range 20-50 years) allocated into two intervention groups: eye patching and OCL. The primary outcome variable was logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), and secondary outcomes were mfVEP amplitude and latency and patients' health-related quality of life National Eye Institute Visual Function Questionnaire (NEI VFQ-25). RESULTS: Significant improvements in pre- to postamblyopic therapy BCVA were seen at 1.5 months in the OCL group [0.29 logMAR, 95% confidence interval (CI): 0.10-0.47 versus 0.11 logMAR, 95% CI: 0.02-0.19; p < 0.001] and eye patching group (0.29 logMAR, 95% CI: 0.17-0.40 versus 0.18 logMAR, 95% CI: 0.12-0.23; p < 0.01). Post-treatment BCVA was inversely related to age (R: 0.009, 95% CI: -0.02 to -0.001; p = 0.04) and the presence of strabismus (R: -0.3, 95% CI: -0.434 to -0.17; p = 0.001). No significant changes in the number and size of the abnormal mfVEP amplitude and latency defects were observed after occlusion. The NEI VFQ-25 composite score showed significant improvement in the OCL users at 12 months compared to eye patching. CONCLUSION: Significant vision improvement can be achieved, making occlusion with OCLs an effective and more acceptable therapy for adults with amblyopia.

Evaluation of visual function and retinal structure in adult amblyopes.

PURPOSE: To evaluate visual function and its relationship to structure in adult amblyopic subjects. METHODS: This observational, cross-sectional study included 24 adult amblyopes and 19 healthy subjects. The amblyopes were separated into three groups: anisometropic amblyopes (n = 15), strabismic amblyopes (n = 5), and strabismic amblyopes with anisometropia (n = 4). The relationships of the multifocal visual evoked potential (VEP) results with the clinical findings and psychophysical (Humphrey visual field) and structural (spectral domain optical coherence tomography) diagnostic test data were then investigated. RESULTS: Significant differences in the multifocal VEP amplitude responses (abnormal cluster defects), combining the interocular and monocular probability analysis, were observed between the anisometropic amblyopic (80%) and nonamblyopic eyes (13.3%) (p < 0.001), whereas in strabismic amblyopia, such defects were found in 100% of the amblyopic and nonamblyopic eyes. Delayed multifocal VEP interocular and monocular latencies were seen in 66.6 and 26.6% of the anisometropic amblyopic and nonamblyopic eyes, with no significant differences between eyes (p = 0.065). Likewise, latency delays were found in 40% of both strabismic amblyopic and nonamblyopic eyes. Multifocal VEP latency showed significant differences between anisometropic and strabismic amblyopic eyes (p = 0.036). Significant agreement was found between the Humphrey visual field and the multifocal VEP visual field defects in the central area of the visual field (p = 0.033). The average retinal nerve fiber layer thickness, foveal and macular thickness, and macular volume, as measured by spectral domain optical coherence tomography, did not show any significant differences between the amblyopic and nonamblyopic eyes and the control group. CONCLUSIONS: Multifocal VEP amplitudes and latencies were significantly affected in amblyopic eyes and, to a lesser extent, in nonamblyopic eyes. Multifocal VEP response latencies were more delayed in anisometropic eyes than in strabismic eyes, suggesting that anisometropic and strabismic amblyopia may represent different neural abnormalities.