Severity of visual field defects in primary congenital glaucoma and their risk factors.

PURPOSE: The primary objective of the study was to assess the frequency and severity of visual field defects (VFD) in primary congenital glaucoma (PCG). The secondary objective was to ascertain any associated risk factors. METHODS: An ambispective review of patients with PCG on follow-up with a 'target' intraocular pressure (IOP) of /= 5 years of age with best corrected visual acuity >/= 6/60 were subjected to manual kinetic Goldmann perimetry, and visual field defects (VFD) were identified. RESULTS: Seventy-one of 90 eyes completed a reliable kinetic perimetry. The mean age of children was 12.34 +/- 4.86 years, and the mean follow-up duration was 10.77 +/- 4.69 years. Baseline IOP and CDR were 29.07 +/- 8.83 mmHg and 0.66 +/- 0.22, respectively. 86.67% of eyes underwent a trabeculotomy + trabeculectomy with mitomycin-C. Thirty-one eyes (34.44%) required a second surgery, 25 of which were bleb revisions and 3 trabeculectomies. Mean IOP and CDR during last visit were 10.23 +/- 2.76 mmHg and 0.52 +/- 0.25, p 0.8, undergoing just a trabeculectomy with MMC, needing >/= 2 glaucoma medications on review or a repeat trabeculectomy was associated with greater severity of VFD. On univariate logistic regression, eyes that needed a bleb revision [OR, 95% CI 9.75 (2.66-35.67), p = 0.001], a repeat trabeculectomy with mitomycin-C [OR (CI) 18 (1.31-245.58), p = 0.03] and final CDR of > 0.8 [OR (CI) 23.1 (3.7-144.21), p = 0.001] were associated with VFD. On multivariable regression analysis, female sex [OR (CI) 18 (2.01-161.04), p = 0.01] was identified as the single most important risk factor for development of a VFD. CONCLUSION: At a 'target' IOP of 0.8, necessity for >/=2 medications or a repeat glaucoma surgery, and female sex were identified as risk factors for development and greater severity of glaucomatous VFD.