Abstract
Purpose: :
The Early Treatment Diabetic Retinopathy Study recommended that laser treatment for eyes with hard exudates (HE) associated with adjacent retinal thickening in the center of the macula or at 500 µm, which is defined as clinically significant macular edema (CSME), be undertaken. However, the amount of HE associated with CSME dose not always increase in natural course, and may generally be divided between HE regression (group A) and HE aggravation (group B) even if patients did not accept laser photocoagulation. Therefore, we studied the differences in systemic background and functional outcome between the two groups.
Methods: :
We compared total cholesterol (TC), triglyceride, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), HbA1c, duration of diabetes, glomerular filtration rate (GFR), and LogMAR best-corrected visual acuity (BCVA) between group A (n = 21) and group B (n = 22) using retrospective observational non-randomized controlled study methods. The study eyes of all subjects with type 2 diabetes had: (1) nonproliferative diabetic retinopathy and HE associated with CSME at baseline; (2) baseline BCVA of 0.1 or better; and (3) no history of ophthalmic treatments for diabetic retinopathy and maculopathy. They were followed for the study period (at least 6 months) without ophthalmic treatments, and color fundus photographs which were performed to estimate the amount of HE associated with CSME at baseline and at the final follow-up visit were used to classify them into the two groups.
Results: :
The mean follow-up was 17.3 ± 8.4 months for group A and 16.0 ± 8.5 months for group B. The mean age was 58 ± 9 years for group A and 56 ± 12 years for group B. There was a significant difference between group A and group B in mean TC (194 ± 36 vs. 219 ± 31 mg/dl, p = 0.016) and mean LDL (114 ± 28 vs. 140 ± 24 mg/dl, p= 0.003) throughout the follow-up period. Triglyceride, HDL, HbA1c, duration of diabetes, and GFR were not different between the two groups. The final mean BCVA was significantly higher in group A compared with that in group B (-0.03 ± 0.11 vs. 0.07 ± 0.17, p= 0.028). Separate within-group analysis showed significant decrease in BCVA from baseline at the final follow-up in group B (-0.05 ± 0.06 to 0.07 ± 0.17, p= 0.003).
Conclusions: :
For patients having HE associated with CSME, regulation of elevated TC and LDL before affecting their VA might result in better macular anatomical outcome and preservation of vision without laser photocoagulation.
Keywords: diabetic retinopathy • edema • clinical (human) or epidemiologic studies: risk factor assessment