Uveitic Glaucoma: Intensive Treatment Necessary Following Trabeculectomy

Although topical or oral medications can control most cases of uveitic glaucoma, 35% of adults and 60% of children eventually need filtration surgery to improve the drainage of aqueous humor from the eye, reduce intraocular pressure (IOP), and preserve optic nerve function.

If patients need such surgery, several options may be considered. For adults, one option is trabeculectomy, the removal of some of the trabecular meshwork near the drainage angle to create a fistula that allows aqueous humor to bypass clogged trabecular channels and flow through the angle. Another option is the placement of an aqueous shunt, also known as a glaucoma drainage device or glaucoma device implant (GDI).

In contrast with adults, children typically receive a trabeculotomy, which involves making incisions in the trabecular meshwork without removing tissue.

However, the interplay between glaucoma surgery and uveitis has remained unclear, especially regarding the impact of uveitis on the outcomes of different types of surgery.

To compare the outcomes of trabeculectomy with those of GDI placement and to determine the effect of uveitis activity on these outcomes, an Australian and British team retrospectively reviewed the results of 82 cases of uveitic glaucoma treated with either trabeculectomy (54 cases) or GDI surgery (28 cases) from December, 2006, through November, 2014. Patients were followed-up for an average of 26 ±22 months. The team was led in part by Associate Professor Lyndell Lim (pictured), PhD, FRANZCO, clinical trials research leader at the Centre for Eye Research Australia at the University of Melbourne.

The goal of the study was to determine whether surgery was successful (as defined in the guidelines of the World Glaucoma Association) and to examine the associations between uveitis factors and surgical outcomes by using univariate and multivariate analysis.

The team determined that the success rate for trabeculectomy, 67%, did not differ significantly from that for GDI, which was 75% (P = 0.60). Furthermore, they found that primary and secondary GDI surgeries had similar success rates. They also determined that hypotony was the most common surgical complication and occurred in approximately 30% of cases.

The team reported that the trabeculectomy group included more cases with active uveitis at the time of surgery (35%) than the GDI group did (14%). However, active uveitis during surgery did not increase the risk of trabeculectomy failure to a statistically significant degree.

Nevertheless, they found that recurrence of uveitis after surgery was associated with surgical failure to a significant degree in the trabeculectomy group but not in the GDI group (odds ratio, 4.8; P = 0.02). Therefore, the investigators concluded that early and prolonged intensive treatment of ocular inflammation is especially important for surgical success after trabeculectomy.

In a related study, a Quebecois team determined that trabeculotomy is safe and effective in children with uveitic glaucoma. That team retrospectively reviewed the records of all pediatric patients who had trabeculotomy for uveitic glaucoma at Ste-Justine University Hospital Centre at the University of Montreal between 2008 and 2014.

During that period, 33 trabeculotomies were done in 28 eyes. In patients whose uveitis was medically controlled, two trabeculotomies per eye were done if necessary for IOP control.

The study included 22 patients whose mean age at surgery was approximately 10 years (range, 5—17 yr). Their diagnoses included uveitic glaucoma associated with juvenile idiopathic arthritis (68%), with idiopathic uveitis (23%), or with pars planitis (9%). Mean follow-up was 34 months (range, 10–78 mo).

The team defined a successful surgical outcome as a final IOP of < 22 mmHg but ≥ 6 mmHg with or without medical therapy. Using this definition, they reported a surgical success rate of 82%. However, four eyes (12%) needed a second trabeculotomy to meet the success criteria, and another four eyes (8%) needed filtration procedures to do so.

The investigators reported that mean IOP decreased from 31.4 mmHg before surgery to 15.0 mmHg at the final visit. In addition, the mean number of glaucoma medications required for IOP control decreased from 4.2 before surgery to 0.4 at the final visit. After surgery, visual acuity and intraocular inflammation remained stable, and no major complications occurred.

The team also did Kaplan-Meier survival analyses and reported the cumulative survival probabilities of the study patients after as many as two trabeculotomies: 1 year after surgery, this probability was 0.86 (95% confidence interval (CI), 0.71—0.93), and 2 years after surgery, it was 0.77 (CI, 0.60–0.87).

They published a report on this study, “Trabeculotomy in the treatment of pediatric uveitic glaucoma,” in the September, 2016, issue of the Journal of Glaucoma.

A report on the first study, “Surgical outcomes of trabeculectomy and glaucoma drainage implant for uveitic glaucoma and relationship with uveitis activity,” was published online in late January, 2017, in Clinical and Experimental Ophthalmology.

Related Coverage:

For Bilateral Uveitic Glaucoma, It May be Best to Operate on Second Eye Sooner than Later

Treating Uveitic Glaucoma No Easy Task for Doctors

Hypotony May Signal Severe Uveitis in Juvenile Idiopathic Arthritis Patients