Postoperative cystoid macular oedema after non-penetrating glaucoma surgery

A comparative study of cystoid macula edema following glaucoma drainage device surgery versus trabeculectomy

PURPOSE

To assess and compare the risk for development of cystoid macula edema (CME) after glaucoma drainage device (GDD) implantation versus conventional trabeculectomy with mitomycin (trab) for glaucoma.

METHODS

Retrospective review of consecutive patients receiving trab or GDD implantation between 2016 and 2018. Inclusion criteria were availability of pre- and postoperative spectral domain optical coherence tomography (SD-OCT) of the macula. SD-OCT images were evaluated for presence of CME qualitatively, central subfield thickness (CST) and macular volume (MV).

RESULTS

73 eyes could be included, 42 received trab and 31 GDD surgery. Eyes receiving trab on average had 0.8 ± 0.8 previous intraocular operations, while eyes with GDD implantation had 3.1 ± 1.9 (p < 0.001). Occurrence of postoperative CME was significantly more frequent after GDD implantation (6 out of 31 (19.4%)) than after trab (2 out of 42 eyes = 4.8%), (p = 0.049). Mean preoperative CST as well as MV was comparable in both groups (CST before trab: 282.7 ± 23.0 µm, CST before GDD 284.2 ± 27.3 µm, p = 0.287; MV before trab: 7.8 ± 1.1 mm3, MV before GDD: 8.0 ± 0.8mm3, p = 0.305). Mean postoperative CST and MV were significantly higher after GDD (CST 338.5 ± 129.3 µm, MV 8.8 ± 2.6 mm3) than after trabeculectomy (CST 290.6 ± 60.2 µm, p = 0.038; MV 7.8 ± 1.2mm3, p = 0.039).

CONCLUSIONS

In real-life conditions, GDD surgery seems to be associated with a higher risk to develop CME when compared to conventional trabeculectomy. This information may be helpful for glaucoma surgeons to advise the patients on postoperative risks of surgery.

Maculopathies in Glaucoma

In the presence of glaucoma, various changes in the macula can occur during the course of the disease itself or its treatment. Maculopathies that can be observed in glaucoma include cystoid macular edema, hypotony maculopathy, and microcystic macular edema. The following article discusses the pathophysiology, causes, course, clinical presentation, and treatment of these maculopathies.