Difference between diabetic macular edema and pseudophakic macular edema using optical coherence tomography

Abstract

Context: Macular edema (ME) is a common pathologic condition causing vision impairment. Diabetic retinopathy is a common cause of ME which can also develop after cataract surgery. Optical coherence tomography (OCT) is a noninvasive diagnostic technique that provides imaging of fine retinal details. Proper diagnosis of the underlying etiology shall affect the management. Aims: This study aims to differentiation between diabetic and pseudophakic ME (DME and PME) using OCT. Settings and Design: Cross-sectional study of 2 Groups; A: 30 eyes with DME and B: 20 eyes with PME. Subjects and Methods: Full clinical evaluation, OCT scanning, and data analysis were done for both groups. Statistical Analysis Used: SPSS software v. 16 was used for: Descriptive statistics, mean, range, and standard deviation. Student's t-test was used for comparison between means. Pearson correlation coefficient was used to assess correlation between variables. Results: Maximum macular thickness and central macular thickness were elevated in both groups but were higher in PME group (P = 0.042 and P = 0.00001, respectively). Macular thickness/volume ratio (TVR) was higher in PME group (P = 0.00001). Cystic changes had different distribution patterns; ganglion cell layer and retinal nerve fiber layer layers were free in PME(Pseudophakic macular edema) while inner nuclear layer and outer nuclear layer were affected in both groups (P = 0.0061). Epiretinal membranes were found much more in DME group (P = 0.0452). Dome-shaped macula was frequently noticed in PME group (P = 0.043). Conclusions: PME and DME have different OCT features; higher TVR, dome-shaped macula, absence of ERM suggest PME while lower TVR, presence of inner retinal cysts and/or ERM suggest DME.