Greater subfoveal choroidal thickness in AMD eyes; more injections needed
By Cheryl Guttman Krader;Reviewed by Aleksandra Rachitskaya, MD
In patients with exudative age-related macular degeneration (AMD), greater subfoveal choroidal thickness (SFCT) at presentation correlated with need for more injections during the first year of anti-VEGF therapy, according to findings of a retrospective study conducted at the Cleveland Clinic Cole Eye Institute, Cleveland.
“We know that abnormalities in choroidal circulation are involved in AMD pathogenesis and that the choroid tends to be thinner in eyes of patients with AMD compared to age-matched healthy controls,” said Aleksandra V. Rachitskaya, MD, assistant professor of ophthalmology, Cleveland Clinic Lerner College of Medicine. “Although there is significant variation in this feature, we hypothesized that greater thickness of the subfoveal choroid in exudative AMD eyes might be a positive prognostic factor.
“Therefore, we were surprised to find that eyes with a thicker subfoveal choroid required more injections,” Dr. Rachitskaya added. “Our data suggest that imaging to determine SFCT may be helpful to retina specialists for anticipating how individuals with exudative AMD may respond to anti-VEGF injections.”
Dr. Rachitskaya said further research is needed to investigate these results in larger populations of patients of different age, race, and undergoing various treatment protocols.
Data results
The study included data from 62 patients with treatment-naïve exudative AMD who underwent serial follow-up with SD-OCT (Cirrus, Carl Zeiss Meditec) at 3-month intervals after beginning anti-VEGF therapy. The patients ranged in age from 64 to 97 years and were almost equally divided between men and women.
The patients were predominantly Caucasian (97%), and mostly treated with bevacizumab (Avastin, Genentech) (93.5%). Subfoveal choroidal thickness at baseline ranged from 70 µm to 361 µm and was significantly associated with age, being lower in older patients.
Data from follow-up visits showed that SFCT was unchanged during the first year after starting anti-VEGF injection. A linear regression analysis showed a highly significant correlation between baseline SFCT and number of anti-VEGF injections during the first year.
An analysis with eyes divided into 3 groups according to their baseline SFCT showed that the average number of anti-VEGF injections needed during the first year was significantly greater in eyes presenting with a SFCT >276 µm compared to subgroups with a SFCT <109 µm or 110 µm to 275 µm (9.4 vs. 6.0 and 6.12, respectively).
Additional analyses found no significant association between SFCT and visual acuity pretreatment or after 1 year. There was also no significant correlation between baseline SFCT and the presence of either subretinal fluid or intraretinal fluid.
Aleksandra Rachitskaya, MD
This article is based on a poster presented at the 2017 annual meeting of the Association for Research in Vision and Ophthalmology. Dr. Rachitskaya has no relevant financial interest to disclose.
