Purpose:
To investigate the impact of prostaglandin analogs (PA) on the incidence and treatment of clinically significant diabetic macular edema (CSME).
Methods:
Retrospective chart review of patients with a history of both diabetes mellitus (DM) and primary open angle glaucoma was performed. Eyes were stratified into groups based on CSME development and PA exposure. Patients who developed CSME were followed for type and amount of treatment and time until resolution. Comorbid medical conditions and systemic medicines thought to influence CSME were considered.
Results:
The study included 346 eyes. Eight eyes (3.8%) developed CSME after PA therapy initiation (group 1a). Group 1a had DM for a mean of 18.8 years and took an average of 18.3 months for CSME resolution. Nine eyes (4.3%) developed CSME prior to initiation of PA therapy (group 1b). Group 1b had DM for a mean of 23.2 years and took an average of 16.6 months for CSME resolution. Group 2 consisted of 193 (55.8%) eyes that were treated with PA but never developed CSME. Mean duration of DM was 13.4 years. CSME developed in 25 eyes (7.2%) that were never exposed to PA (group 3). Group 3 had DM for a mean of 20 years and took an average of 12 months for CSME resolution. Group 4 consisted of 111 eyes (32.1%) not exposed to PA and without CSME. Mean duration of DM was 12.5 years. Duration of DM was longer (p=0.0001) in eyes that developed CSME (20.5 mo) compared to eyes that did not (13.7 mo). There was no significant difference (p=0.75) in duration of DM in eyes that developed CSME and were exposed to PA (21.1 mo) compared to eyes that were not (20.0 mo). PA treated eyes had a longer interval until resolution of CSME (17.4 mo) compared to PA untreated eyes (12 mo); this difference was not significant (p=0.18). Homogeneity existed among all groups with respect to amount of focal laser required for CSME resolution, incidence of hypertension, dyslipidemia, and ACE inhibitor exposure.
Conclusions:
CSME development correlated most strongly with duration of DM. CSME occurred more often in patients not treated with PA. However, there was a trend towards longer interval until resolution of CSME in eyes exposed to PA, independent of duration of DM.
Keywords: diabetes • macula/fovea • edema