Comparison of Anatomical and Functional Outcomes of Intravitreal Dexamethasone Implant between Phakic and Pseudophakic Eyes with Diabetic Macular Edema

PURPOSE: To compare the effectiveness of dexamethasone (DEX) intravitreal implants for the treatment of diabetic macular edema between phakic and pseudophakic eyes after a follow-up. METHODS: A total of 79 eyes in 79 patients with diabetic macular edema who were insufficiently responsive to the previous anti-vascular endothelial growth factor treatment and applied intravitreal DEX implant were included in this retrospective study. The patients were divided into two groups according to their type of lenses: pseudophakic (group 1) and phakic (group 2). Best-corrected visual acuity, intraocular pressure (IOP), retinal nerve fiber layer thickness, and central macular thickness changes in the two groups were compared. RESULTS: Group 1 comprised 42 eyes in 42 patients with a mean age of 64.02 ± 3.79 years, while group 2 comprised 37 eyes in 37 patients with a mean age of 64.19 ± 5.08 years. In both groups, best-corrected visual acuity improved significantly with a significant decrease in central macular thickness (p < 0.001). In both lens types, the IOP values decreased significantly on the first day but subsequently increased significantly compared to baseline from one week to six months. Increases in IOP values were significantly higher in group 1 at the first week, 1st month, and 6th month compared with group 2. During follow-up, the inferior quadrant retinal nerve fiber layer showed a significant decrease in both groups. CONCLUSIONS: In both phakic and pseudophakic eyes, intravitreal DEX implantation is an effective treatment method with low-risk complications. In our study, the pseudophakic group experienced a significantly earlier increase in IOP and at higher levels than did the phakic group. In light of these data, we suggest that in patients with pseudophakic eyes, follow-ups for IOP should be stricter and started earlier after intravitreal DEX treatment.