Surgical failure, cataract more common in uveitic glaucoma

This retrospective study found that trabeculectomy with MMC was less effective in eyes with uveitic glaucoma than in eyes with primary open angle glaucoma (POAG).

This study out of Japan is the largest retrospective study to date investigating uveitic glaucoma patients. It nicely demonstrates the increased risk of failure of trabeculectomy in uveitis patients and the need to consider other surgical options in this group (such as glaucoma drainage devices), especially in pseudophakic patients with granulomatous uveitis.

The authors compared surgical success and complications, including cataract progression, after trabeculectomy with MMC between 101 uveitic glaucoma patients and 103 POAG patients. Surgical failure was defined as IOP ≥ 21mm Hg or an additional glaucoma surgery.

Uveitic glaucoma had a significantly lower cumulative probability of surgical success at three years (P = 0.0171) and a significantly higher cumulative probability of postoperative cataract surgery (P < 0.0001). In addition, the Cox proportional hazard model revealed that previous cataract surgery (RR = 2.957, P = 0.0344) and granulomatous uveitis (RR = 3.805, P = 0.0106) were prognostic factors for surgical failure of trabeculectomy. There was no significant difference in the frequency of other surgical complications between the two groups.

This should make one consider use of other surgical options (e.g., glaucoma drainage device) for better long-term outcomes following glaucoma surgery given the increased risk of trabeculectomy failure in uveitics. This should definitely hold true in a pseudophakic patient with granulomatous uveitis who will have an even greater risk of failure. If, however, a low target IOP is needed, one should bear in mind that the success of a trabeculectomy even in uveitics was 62 percent and presumably higher in phakic patients or patients with nongranulomatous uveitis.

An additional word of caution is that the uveitic group was younger and had higher intraocular pressures at the time of surgery, both of which could be factors influencing the higher failure rate in this group.

In conclusion, uveitic patients undergoing trabeculectomy should be strongly counseled about the increased risk of failure and the greater chance of cataract development.