Patterns of retinal thickness prior to and following treatment with fluocinolone acetonide 190 μg intravitreal implant for diabetic macular edema

Objectives: To compare retinal thickness before and after treatment with the fluocinolone acetonide (FAc) 190 mu g intravitreal implant in people with diabetic macular edema (DME) using data from the Iluvien Clinical Evidence study in the UK (ICE-UK). Methods: For this retrospective cohort study, data on people attending any one of 13 participating ophthalmology departments and treated with FAc intravitreal implant between April 1, 2013 and April 15, 2015 were collected for 12 months prior to and at least 12 months after implantation. Cross-sectional and longitudinal patterns of central foveal thickness (CFT) were compared before and after FAc implant. Results: There were 208 people who contributed data from 233 individual eyes treated with the FAc implant. Mean age was 68.1 years and 62% were male. Median (interquartile range) CFT decreased from 462 mu m (354-603 mu m) at time of implant to 309 mu m (222-433 mu m) at 12 months post-implant (p<.001). Over the same period, a reduction of >= 10%, >= 25%, and >= 50% in CFT was observed in 113 (65%), 87 (50%), and 37 (21%) treated eyes, respectively. Eyes with a CFT of 400 mu m at the time of implant were significantly more likely to achieve a reduction in CFT of >= 10%, >= 25%, and >= 50% at 12 months (all p<.001) compared with eyes with a CFT of <400 mu m at implant. Both retinal thickness and changes in retinal thickness were loosely correlated with visual acuity. Conclusion: A marked reduction in retinal thickness was observed in people following FAc intravitreal implant for DME. The response was related to the degree of retinal thickness prior to treatment.