Evaluation of the Factors Associated With the Reversal of the Disc Cupping Following Surgical Treatment of Childhood Glaucoma

Abstract

Purpose:: Evaluate the reversal of optic disc cupping after surgical procedure for congenital glaucoma and assess the factors which may intervene on this process.

Methods:: Prospective study involving 45 eyes of 36 patients with childhood glaucoma, who underwent surgical treatment at the Hospital Municipal da Piedade, Rio de Janeiro, Brazil, between January 1998 and December 2005. The study included patients <5 years old with IOP<19mmHg for at least six months following surgery. The excluding criteria were: children who were ≥ 5 years old, IOP ≥ 19mmHg after surgery and cloudy media. All patients were examined under narcosis before and one, three and six months after surgery in order to assess IOP by applanation tonometry, to measure the horizontal corneal diameter, perform biomicroscopy, gonioscopy and to evaluate cup-to-disc ratio under pupil dilatation. After this period the follow-up was performed every six months. In order to meet study criteria, vertical axis of the cup-to-disc ratio (C/D) was considered. The stabilization of the optic disc was confirmed in at least two consecutive tests by the same examiners that were not aware of the previous test. All surgeries were performed by the same surgeon. The variables evaluated and correlated were age at the time of the surgery; vertical axis of C/D; IOP as well as the horizontal corneal diameter preoperatively; quantity and type of surgery performed; range of IOP reduction; number of antiglaucomatous drops taken postoperatively and the type of glaucoma. The statistical methods applied were Student-t test for paired samples and for independent samples and Multivariate analysis of multiple linear regression and of multiple logistic regressions.

Results:: There was a significant difference (p<0,001) between the pre (0,75 ± 0,15) and postoperatively (0,62 ± 0,22) C/D and the IOP measured pre (22,40 ± 4,93mmHg) and postoperatively (12,33 ± 3,84mmHg). The variables which statistical significance correlation to the reversal of cupping were age at the time of surgery (p=0,008) and the reduction of the IOP after surgery (p=0,048). A higher reduction of cupping was observed in children ≤ 1 year old (0,18 ± 0,12) at the time of the surgical procedure.

Conclusions:: Optic disc cupping can be reversed at an early stage of primary congenital glaucoma following successful reduction of IOP. Younger age at surgery was associated with reversal of cupping, specially in children operated before 1 year of age.

Keywords: optic disc • intraocular pressure • visual development: infancy and childhood