Session Title: Vascular Diseases and Diabetic Retinopathy III
Session Date/Time: Saturday 19/09/2015 | 16:30-18:00
Paper Time: 16:54
First Author: : D.Sahota UNITED KINGDOM
Co Author(s): : G. Reid M. Sarhan
PURPOSE:Intravitreal dexamethasone implant (IDI) has been demonstrated to improve visual acuity and reduce loss in visual acuity in macular oedema (MO) secondary to retinal vein occlusion (RVO). However, few published studies demonstrate the efficacy over multiple treatment rounds and whether there is a difference in response to IDI between central (CRVO) and branch (BRVO) retinal vein occlusion.
We describe the response to re-treatment with IDI over three treatment rounds in patients with MO secondary to CRVO or BRVO, who met NICE guidelines for treatment.
Retrospective study of consecutive patients receiving IDI for treatment of MO secondary to RVO in UK single-centre setting (Calderdale Royal Hospital, Yorkshire) from September 2011 to April 2013. Follow-up period was 6-months after each implantation, when treatment was stopped or further implantation undertaken (to a maximum of 3 implants).
Implants were performed in a clean room with aseptic technique under local anaesthetic following preparation with povidone-iodine 5%. Patients were prescribed a 5 day course of topical levofloxacin after the procedure. Treatment criteria was the presence of MO on OCT (Central Macular Thickness (CMT) greater than 250μm) as a result of RVO within 2 years of onset and best corrected visual acuity (BCVA) of 24 letters logMAR (6/96) or better. Retreatment was indicated unless BCVA was better than 80 letters logMAR (6/7.5) or if there was resolution of MO (CMT less than 250μm). Treatment was stopped if intolerable side-effects occurred, if another treatment was favoured (anti-VEGF or photocoagulation) or if the patient did not consent to further IDI. Retrospective case-note review with data collection of demographics, past ophthalmic history and nature of RVO (CRVO or BRVO). Outcome measures were BCVA and CMT at initiation, 2 months and 6 months post-treatment. BRVO vs. CRVO sub-groups were compared. Statistical significance was calculated by Student t-test with a p-value less than 0.05 deemed as significant.
60 eyes received initial IDI. Mean age was 72.4 years with 35 (58%) female. 34 were BRVO (57%), 26 (43%) CRVO. Mean initial BCVA and CMT were 0.83 and 524μm. Mean BCVA and CMT were 0.63 and 282μm at 2months; 0.78 and 424μm at 6months. 17 eyes received second IDI (11 BRVO, 7 CRVO). Mean re-treatment interval 6.7months. Mean BCVA and CMT were 0.81 and 469μm at initiation; 0.65 and 291μm at 2months; 0.84 and 458μm at 6months. 6 eyes received third IDI (4 BRVO, 2 CRVO). Mean re-treatment interval 6.8months. Mean BCVA and CMT were 0.87 and 437μm at initiation; 0.65 and 291μm at 2months; 0.84 and 458μm at 6months. At first presentation, mean initial BCVA and CMT were significantly worse in CRVO (0.96, 587μm) vs. BRVO (0.74, 476μm). After first IDI, mean decrease in CMT at 2months was higher (p=0.003) in CRVO (303μm) vs. BRVO (195μm). Difference in mean change in BCVA at 2months in CRVO vs. BRVO was not significant (p=0.25). In second and third IDI groups, there was no significant difference in BCVA or CMT change at 2months in CRVO vs. BRVO.
IDI increases the incidence of improvement in BCVA and CMT in patients with MO secondary to RVO. The improvement in BCVA and CMT at 2 months is however negated after 6 months back to pre-treatment levels, as previously demonstrated by the GENEVA study group after initial IDI. The statistically significant improvement in BCVA and CMT at 2 months continues with a second and third IDI but does not persist at 6 months even with multiple IDIs (up to 3). Mean BCVA and CMT at 6 months follow-up has no statistically significant difference compared to baseline in any treatment round. Multiple treatment rounds of IDI are an effective therapy for MO in both BRVO and CRVO with neither group responding better than the other at 2 months in terms of visual improvement. However after the first IDI there is a better anatomical response in CRVO which may be due to higher CMT at baseline in CRVO vs. BRVO.