Effect of aflibercept on persistent macular edema secondary to central retinal vein occlusion.

PURPOSE: To evaluate the efficacy of switching treatment from intravitreal ranibizumab to intravitreal aflibercept on the treatment of refractory macular edema secondary to central retinal vein occlusion (CRVO). METHODS: In this retrospective study; 12 eyes with refractory macular edema secondary to CRVO after multiple monthly repeated intravitreal 0.5mg/0.05mL ranibizumab injections prior to switching therapy to intravitreal 2mg/0.05mL aflibercept, between March 2012 and April 2016 were reviewed. The follow-up time was 12 months. Changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), central retinal volume (CRV) and injection interval between baseline and month 1, 3, 6 and 12 after switching therapy to aflibercept were reviewed and evaluated. RESULTS: Mean baseline CRT decreased from 516±101 mic. to 252±114 mic. at month 12 (P=0.008). Mean baseline CRV decreased from 8.74±2.13 mm3 to 6.82±1.64 mm3 at month 12 (P=0.005). Baseline BCVA improved from 0.73±0.21 to 0.53±0.17 logMAR at month 12 (P=0.004). Mean BCVA gain was two logMar lines (10 letters) at month 12. After switching therapy to aflibercept; the mean injection interval increased significantly from 1.34 months at baseline to 1.86 months at month 12, by an increase of 0.52 months (P=0.02). CONCLUSION: Intravitreal aflibercept is evaluated to be presenting significant visual and anatomical improvements in patients with persistent macular edema due to CRVO despite previous intravitreal ranibizumab.

Comparison of different formulas for intraocular lens power calculation using a new optical biometer.

PURPOSE: To evaluate and compare the predictability of different formulas for intraocular lens (IOL) power calculation using a new optical biometer (Aladdin). METHODS: This prospective cross-sectional study included 70 eyes of 70 patients who underwent uneventful phacoemulsification with IOL implantation. Preoperative IOL power calculations were performed using the Aladdin optical biometer. Postoperative actual refractive errors and errors predicted by the SRK/T, SRK II, Holladay 1, Hoffer Q and Haigis formulas were analyzed. The mean estimation error (EE), mean absolute estimation error (AEE) and the percentage of eyes within ± 0.50 and ± 1.00 D of the target refraction for each of five formulas were calculated and compared. This analysis was also repeated in three groups formed based on axial length (AL) (group 1: <22.5mm, group 2: 22.5-24 mm, group 3: >24 mm). RESULTS: In the overall study group, the smallest mean AEE was provided by the Holladay 1 formula, however there was no statistically significant difference in the mean AEE's predicted by the five formulas (P=0.34). The highest percentage of eyes within ± 0.50 and ± 1.00 D of the target refraction was also found by using Holladay 1 (71% and 97%). SRK/T provided smallest mean AEE for groups 1 (n=13) and 3 (n=16). In group 2 (n=41), the smallest mean AEE was obtained using Holladay 1. CONCLUSIONS: Based on the Aladdin biometric data used in our study, better results can be obtained using SRK/T formula in eyes with short or long AL. The Holladay 1 formula may be preferred in eyes with moderate AL.