Severe Glaucoma May Influence Microcystic Macular Edema

Optic disc affected by glaucoma.
Microcystic macular edema not associated with faster global visual field decay among patients with primary open-angle glaucoma, according to a study.

More severe stages of glaucoma and younger age are associated with microcystic macular edema (MME) in patients with primary open-angle glaucoma (POAG), according to a study published in the British Journal of Ophthalmology

Between January 2010 and January 2019, researchers conducted a retrospective chart review of patients seen at the Glaucoma Division, Stein Eye Institute. They analyzed 315 eyes of 190 patients with POAG. All participants had good-quality macular volume scans that included reliable visual fields (VF) available within 6 months. The study excluded eyes with retinal pathologies except for epiretinal membrane (ERM). The investigators qualitatively evaluated the inner nuclear layer for the presence of MME. They used linear regression to estimate global mean deviation (MD), Visual Field Index (VFI) decay rates, superior and inferior MD rates as well as pointwise total deviation rates of change. They used logistic regression to identify baseline factors associated with the presence of MME and to determine whether MME is related to progressive VF loss.

The researchers identified MME in 25 eyes (8%) of 24 patients (12.6%). In total, 218, 55 and 42 eyes were classified as having mild, moderate and severe stages of glaucoma, respectively. The average age and MD in eyes with and without MME was 57.2±8.7 vs 62.0±9.9 years (P =.02) and -9.8±5.7 vs -4.9±5.3 dB (P <.001), respectively, according to the report.  

In mixed multivariate logistic regression, younger age (OR: 0.9, 95% CI 0.902 to 0.992, P =.02) and worse baseline MD (OR: 0.89, 95% CI 0.83 to 0.95, P =.01) were associated with the presence of MME in patients with POAG. The team notes that ERM was not associated with the presence of MME (P =.84). 

“MME was not associated with faster global VF decay in this cohort,” the researchers report. “MME may confound monitoring of glaucoma with full macular thickness.”

Study limitations include the small sample size of patients with MME and sometimes the quality of the optical coherence tomography scans were inadequate. 

Disclosure: This research was supported by multiple sources. Please see the original reference for a full list of authors’ disclosures. 

Reference

Mahmoudinezhad G, Salazar D, Morales E, et al. Risk factors for microcystic macular oedema in glaucoma. Br J Ophthalmol. Published online November 5, 2021. doi:10.1136/bjophthalmol-2021-320137