After uneventful cataract surgery, continuation of prostaglandin therapy did not increase incidence of cystoid macular edema, according to research results published in the British Journal of Ophthalmology.
Researchers conducted a prospective, randomized study (ClinicalTrials.gov identifier NCT03292796) to determine whether the discontinuation of prostaglandin analogue therapy after uncomplicated cataract surgery can reduce the risk of cystoid macular edema development in patients with either primary open angle glaucoma or ocular hypertension.
The study population included patients with either condition older than 16 years of age who had been prescribed topical prostaglandin analogue therapy for at least 2 months and were scheduled for routine cataract surgery at 1 of 2 centers.
The study cohort included 62 eyes from 62 patients who were randomly assigned 1:1 to either continue or discontinue prostaglandin analogue therapy (n=31 in each group). Patients were postoperatively evaluated at 1 day, 1 week, and 1 month after surgery; IOP was measured at each visit and a macula optical coherence tomography (OCT) scan was performed at 1 week and 1 month.
The primary study outcome was the presence of cystoid macular edema on OCT imaging at the 1-month follow-up. The secondary study outcome was the change in IOP from baseline during the same time.
Baseline patient characteristics between groups were similar in terms of age, gender, glaucoma diagnosis, mean preoperative IOP, type of prostaglandin analogue therapy, and treatment duration, among other variables.
No incidences of cystoid macular edema were detected in either group at the 1 week follow-up visit. At 1 month, 12.9% of patients in each group presented with cystoid macular edema (odds ratio, 1.000; 95% CI, 0.227-4.415). All eyes that developed cystoid macular edema experienced a resolution in cystoid changes at a mean 3.0±0.8 months after treatment with topical ketorolac trometamol (0.5%) 3 times daily.
Among the eyes that developed cystoid macular edema, CMT increase from baseline was not significantly different (91±114 µm vs 11±9 µm in the continue vs discontinuation groups). All increases in CMT were <52 µm, with the exception of 1 eye in the continuation group that experienced an increase of 260 µm from baseline.
All 4 prostaglandin analogue therapies were implicated in cystoid macular edema development, although duration of treatment, number of topical antiglaucoma medications, treatment with preserved drops, and effective phacoemulsification time were not related.
On the first postoperative day, there was a significant IOP increase of 3.3±5.9 mm Hg from baseline in the continuation group, while IOP was similar in the discontinuation group. At week 1, IOPs in each group were similar to baseline with no between-group difference. At 1 month, researchers saw a significant reduction in IOP vs baseline in the continuation, but not in the discontinuation group.
Study limitations include the possibility that the study may have been underpowered to detect an intergroup difference and a lack of evaluation of whether it is beneficial to stop prostaglandin analogue therapy postoperatively in patients who have macular disease.
“In patients with no macular pathology, it may be beneficial to continue prescribing topical [prostaglandin analogues], if appropriate for IOP control, with no apparent risk of increasing the development of postoperative [cystoid macular edema,” the study concludes. “The results of the present study augment the findings of a recent publication meta-analysis, which suggested that there was no evidence for stopping [prostaglandin analogues] after cataract surgery with respect to the development of [cystoid macular edema].”
Niyadurupola N, Brodie J, Patel T, et al. Topical prostaglandin analogue use and cystoid macular oedema following uneventful cataract surgery: A randomized control trial. Br J Ophthalmol. Published online May 27, 2021. doi:10.1136/bjophthalmol-2021-319149