Abstract
Purpose :
Choroidal neovascularization membranes (CNVM), a progressive, advanced form of age-related macular degeneration results in vision loss. Varying response to intra-vitreal injection therapy has been observed. Hence, this study aims to determine the association between the levels of various soluble secreted factors in the aqueous humour and response of macular edema to therapy in CNVM patients.
Methods :
Aqueous humour samples were collected from CNVM patients (n=31) undergoing intravitreal anti-VEGF after obtaining informed written consent and prior study approval by the Institutional Ethics Committee. The study subjects included CNVM patients (n=31) undergoing intravitreal anti-VEGF. Routine investigations including OCT imaging along with intravitreal injections were performed during visits. The subjects were then grouped as resolving edema (n=18) and persistent edema (n=8) based on the reduction in edema volume (analysed using MATLAB image processing) between two visits. Cytometric bead array was used for simultaneous quantification of IL-2, IL-4, IL-8, IL-17F, MCP-1, MIP-1β, CXCL9, CXCL10, CXCL11, Fractalkine, CD62L, CD62P, ICAM1, VCAM, Angiogenin and VEGF in aqueous humour collected during first visit.
Results :
VEGF levels in aqueous humour was significantly (p=0.03) lower in the persistent edema group (66±13 pg/ml) compared to resolving edema group (249±92 pg/ml). A significant increase in the levels of ICAM1, VCAM, CD62L and CXCL10 were observed in the aqueous humour of those patients with persistent edema compared to those with resolving edema. A positive correlation was observed between difference in edema volume (between visits) and ICAM1 (r=0.550; p=0.003), VCAM (r=0.455; p=0.01), CD62L (r=0.537; p=0.004) and IL-2 (r=0.424; p=0.03). These observations suggest the possible role of soluble cell adhesion molecules in the response of macular edema to therapy in CNVM patients. In addition, the decreasing trend in central subfoveal thickness was greater in those with resolving edema compared to persistent edema.
Conclusions :
The findings demonstrate a unique set of soluble factors in aqueous humour which may influence or indicate the status of therapy-mediated reduction of macular edema in CNVM patients.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.