Factors influencing the outcome of goniotomy and trabeculotomy in primary congenital glaucoma

Purpose: To study the prognostic factors influencing intraocular pressure (IOP) reduction and success rates of paediatric goniotomy and trabeculotomy.

Patients: Data from patients aged ≤12 years who underwent goniotomy or trabeculotomy for primary congenital glaucoma from 2013 to 2016 were reviewed. The analysis included 452 eyes of which 120 eyes of patients with a median age (IQR) of 6 months (4.1-11 months) underwent goniotomy, and 332 eyes of patients with a median age of 5.2 months (2.3-9.3 months) underwent trabeculotomy.

Methods: Multivariate linear regression analysis was used to predict the correlation of preoperative and operative risk factors to the per cent IOP reduction, while multivariate logistic regression was done to determine independent predictors of failure. Failure was defined as a final IOP >18 mm Hg while on medications or the need for another glaucoma procedure.

Results: In the goniotomy group, the median IOP reduction was 19.4% and was positively correlated to a high initial IOP (p≤0.001) while in the trabeculotomy group, it was 36.8% and mostly influenced by preoperative IOP (p≤0.001), corneal clarity (p=0.04), gender (p=0.04) and consanguinity (p=0.03). The failure rate in the goniotomy group was 56% and was influenced by the preoperative cup-to-disc ratio, while in the trabeculotomy group it was 30% and strongly correlated to positive consanguinity (p≤0.001), higher preoperative IOP (p=0.003), female gender (p=0.01) and younger age at surgery (p=0.03).

Conclusion: Several factors can predict the outcome of angle surgery and can help in deciding the appropriate surgical intervention in paediatric glaucoma. Trabeculotomy seems to be superior to goniotomy in primary congenital glaucoma.