Unilateral Strabismic Amblyopia Research Articles

Assessing Choroidal Thickness in Pediatric Patients With Unilateral Strabismic Amblyopia by Using Spectral Domain-Enhanced Depth Imaging-Optical Coherence Tomography

Assessing Choroidal Thickness in Pediatric Patients With Unilateral Strabismic Amblyopia by Using Spectral Domain-Enhanced Depth Imaging-Optical Coherence Tomography

Monitoring occlusion therapy in amblyopic children using pattern visual evoked potential

Background Amblyopia is a unilateral or bilateral reduction of best-corrected vision that cannot be attributed only to a structural abnormality of the eye. It is a common childhood problem, and can be reversed if treated while the visual system is still maturing. Objective The aim of the present study was to investigate the role of pattern visual evoked potential (PVEP) in the assessment of visual function after occlusion therapy for children with unilateral strabismic amblyopia. Patients and methods Visual function was assessed clinically and using monocular PVEP, elicited by high-contrast checkerboard-patterned stimuli, before and after occlusion of the healthy eye for 1 week for every year of life in 20 children presenting with unilateral strabismic amblyopia. Results PVEP responses were significantly prolonged in latency in amblyopic eyes after the first assessment compared with nonamblyopic eyes. There was no significant difference in the interside amplitude. Assessment after occlusion showed a statistically significant reduction in the latency of the amblyopic eye and statistically significant improvement in the visual acuity. Conclusion PVEP can be used as a method of assessment of visual function after the occlusion therapy for children with unilateral strabismic amblyopia.

Factors Affecting Compliance to Two-Hour Versus Six-Hour Occlusion Therapy Regimens for Treatment of Strabismic Amblyopia

Purpose: To compare the effect of daily occlusion of the sound eye for two hours, without and with near vision exercises, versus six hours without near vision exercises, for the management of strabismic amblyopia and to determine the different factors affecting compliance to each treatment regimen. Methods: Forty five children having unilateral strabismic amblyopia were divided equally into 3 groups. Group A received 2-hour daily occlusion. Group B received 2-hour occlusion combined with near vision exercises. Group C received 6-hour occlusion therapy. Patients were followed up for 6 months. Results: The mean logMAR improvement was -1.03+/-0.57, -0.63+/-0.66 and -0.65+/-0.66, for groups A, B and C, respectively. The difference in mean logMAR improvement was significant (P < .001) in groups A versus B and A versus C, but was insignificant (P =.748) in group B versus C. Factors affecting compliance to each occlusion regimen were related to age, socioeconomic status, life pattern and season of the year.Conclusion: The best outcome was achieved when 2-hour daily patching was combined with near vision activities. Higher compliance to two-hour occlusion with near vision exercises was attained in older, educated children. Six-hour occlusion was more suitable in younger and in uneducated children.

Thickness of the Retinal Nerve Fiber Layer, Macular Thickness, and Macular Volume in Patients With Strabismic Amblyopia

To compare the thickness of the retinal nerve fiber layer (RNFL), the macular volume, and the macular thickness of the amblyopic eye with those of the non-amblyopic eye in patients with unilateral strabismic amblyopia using optical coherence tomography (OCT). OCT was performed for 14 patients with unilateral strabismic amblyopia who had no neurologic disease. Nine male and 5 female patients, whose ages ranged from 5 to 18 years, were enrolled in the study. The RNFL thickness average analysis program was used to evaluate mean superior, inferior, temporal, and nasal thickness. The data for all clock quadrants (12 values averaged) were identified as the overall RNFL. The retinal thickness and volume analysis program was used to evaluate macular scans. Data were compared using the Mann-Whitney U test. The mean age (+/- standard deviation) was 10.43 years (+/- 4.09 years). There were 6 right eyes and 8 left eyes with amblyopia; this group had a mean visual acuity (+/- standard error) of 0.3 (+/- 5.70). OCT parameters including the RNFL thickness in all quadrants, overall RNFL thickness, macular thickness, and macular volume showed no significant differences between the two groups (P > .05). Assessment of RNFL thickness, macular thickness, and macular volume with OCT revealed no difference between the two eyes of patients with unilateral strabismic amblyopia.

Thickness of the retinal nerve fiber layer in amblyopic and normal eyes: A scanning laser polarimetry study

Purpose: To compare scanning laser polarimeter (GDx, Laser Diagnostic Technologies, San Diego, Calif) measurements of the peripapillar retinal nerve fiber layer in amblyopic and normal eyes. Methods: Scanning laser polarimetry was performed on 21 patients with unilateral strabismic amblyopia who had an absence of neurologic diseases or glaucoma and a minimum age of 7 years. A mean retardation map was calculated from separate scans or was considered to be the best scan obtained for each eye. Polarimetric indices were analyzed comparing amblyopic and contralateral normal eyes. Results: The mean age was 15 ± 9 years (7-35 years) and the male:female ratio was 13:8. There were 6 right and 15 left amblyopic eyes, with the amblyopic group having a mean visual acuity of 0.3 ± 0.1. The mean (± SD) indices did not differ significantly between normal and amblyopic eyes, except the number that summates information from the individual parameters, which was higher in normal (20.71 ± 11.98) than in amblyopic (15.14 ± 6.81) eyes, P = .02. Conclusion: There was no statistical difference in thickness of the nerve fiber layer between amblyopic and normal eyes. A previous study found similar results in adults with strabismic amblyopia. (J AAPOS 2001;5:82-4)