EARLY TREATMENT OF SEVERE CYSTOID MACULAR EDEMA IN CENTRAL RETINAL VEIN OCCLUSION WITH POSTERIOR SUB-TENON TRIAMCINOLONE ACETONIDE

Abstract

To evaluate the clinical outcomes of posterior sub-Tenon (PST) injection of triamcinolone acetonide (TA) in the early treatment of severe cystoid macular edema (CME) in central retinal vein occlusion (CRVO). In a noncomparative, prospective study, 18 eyes of 18 patients with severe CME (central macular thickness, CMT >450 microm) secondary to recent-onset CRVO (the onset of symptoms < or =4 weeks) and a decrease in visual acuity (< or =80 letters of Early Treatment Diabetic Retinopathy Study [ETDRS] scores, 20/50) were included. PST injection of 40 mg of TA was given under topic anesthesia. All patients received three biweekly injections and were evaluated at baseline and at 1 day, 1, 2, 4, 6, and 8 weeks, and 3, 6, and 9 months after injection. The main outcome measures were ETDRS scores, CMT, intraocular pressure (IOP), cataract progression, and frequency of complications. The mean age of the 18 patients was 61.17 years (range, 24-81 years) and the mean duration of symptoms was 15.28 days (range, 9-28 days). Eight eyes were diagnosed with ischemic CRVO and 10 eyes with nonischemic CRVO. Mean baseline ETDRS visual acuity (VA) score was 36.89 +/- 18.22 in all affected eye. There was a significant improvement in VA at 1, 3, 6, and 9 months of follow-up. The mean VA at these time points were 46.61 +/- 20.21, 58.11 +/- 22.19, 59.39 +/- 22.98, and 58.67 +/- 23.27 (all P < 0.001), respectively. Both nonischemic and ischemic eyes benefited with a statistically significant VA improvement at each time point. A comparison of the gain in VA between two subgroups was not significant at 1 and 3 months (P > 0.05), but was statistically significant at 6 and 9 months (P = 0.009 and 0.008, respectively). VA gain of 10 or more letters was found in all nonischemic eyes (10/10) and 3 ischemic eyes (3/8) at the 9-month follow-up. Two ischemic eyes were found to have no gain of letters in VA at the 9-month follow-up. The mean baseline CMT for all eyes was 566 +/- 42 microm. There was a 29% reduction with a mean CMT of 404 +/- 49 microm (P < 0.001) at 1 month, 51% reduction with a mean CMT of 278 +/- 40 microm (P < 0.001) at 3 months, 61% reduction with a mean CMT of 222 +/- 56 microm (P < 0.001) at 6 months, and 63% reduction with a mean CMT of 210 +/- 30 microm (P < 0.001) at 9 months. Both nonischemic and ischemic eyes demonstrated a statistically significant reduction in CMT (all P < 0.001). A comparison of the reduction in CMT between these two subgroups was not significant at each visit (all P > 0.05). For both subgroups, there was no statistically significant difference in IOP change at baseline, 1 week, 1, 3, 6, and 9 months of follow-up. Only two patients required topic antiglaucoma drops for elevated IOP. Three patients developed a recurrence of CME accompanied with visual decrease. No cataract progression or other complications were observed. PST injection of TA is effective in reversing CME and improving visual acuity in recent-onset CRVO in the first 9 months. Patients with nonischemic CRVO may respond more favorably than patients with ischemic CRVO. Early treatment may be better for visual improvement before longstanding macular edema results in irreversible photoreceptor damage. Further study with longer follow-up period is necessary.