Measuring intraocular antibodies in eyes treated with anti-vascular endothelial growth factor.

OBJECTIVE: To characterize the total intraocular aqueous humour antibody profiles in cases receiving anti-vascular endothelial growth factor (anti-VEGF) for retinal vascular disease compared with controls without retinal pathology. DESIGN: Cross-sectional. PARTICIPANTS: 93 aqueous humour samples: 22 eyes undergoing cataract surgery (controls) and 71 eyes receiving intravitreal injections (IVI) (cases) for macular edema or neovascularization. METHODS: Antibody isotyping of aqueous humour was performed using Milliplex MAP Human Isotyping Multiplex Assay. Cases and controls were compared for several outcome measures. RESULTS: The primary outcome measure was total mean antibody isotype concentration quantified in the aqueous humour. Secondary outcomes included comparing aqueous humour concentrations with visual acuity, number of IVI received, type of anti-VEGF agent injected, and persistence intra-/subretinal fluid post injection. Mean immunoglobulin M (IgM) concentrations in cases were 19-fold higher compared with controls. Aqueous immunoglobulin G (IgG)1,2,3,4 and immunoglobulin A (IgA) were 2-4-fold higher in cases compared with controls. Disease-specific trends were observed, with diabetic retinopathy (DR) eyes containing the highest amounts of aqueous antibodies. Total number of injections correlated with higher titres of IgG1 (p < 0.001), IgG2 (p < 0.009), and IgG3 (p < 0.001) in all cases analyzed with the strongest correlations seen in DR eyes (r = 0.77, p < 0.001). Presence of aqueous humour antibodies correlated with worse post-IVI best-corrected visual acuity; IgG1 (p < 0.01), IgG2 (p < 0.005), IgG3 (p < 0.01), and IgA (p < 0.003) in all cases analyzed, with the strongest correlations seen in DR eyes (r = 0.74, p < 0.001). CONCLUSIONS: Intraocular antibodies are present in the aqueous humour at significantly higher concentrations in eyes receiving IVIs for retinal vascular diseases compared with controls.

Intraocular calcidiol: Uncovering a role for vitamin D in the eye.

Vitamin D has emerged as a potentially important molecule in ophthalmology. To date, all ophthalmic data pertaining to vitamin D has been restricted primarily to tear and serum analysis in human patients. Considering the isolated nature of the eye, we sought to determine the presence of intraocular vitamin D in ocular disease. METHODS: 25-Hydroxyvitamin D3 (25(OH)D3) concentrations were measured in the eye and blood of 120 participants undergoing ophthalmic procedures. Ocular localization of the 1,25-dihydroxyvitamin D3-generating (CYP27B1) and deactivating (CYP24A1) hydroxylases was performed by immunohistochemistry. Gene expression of CYP27B1, CYP24A1 and VEGF-A was measured in eyes from patients with and without disease. RESULTS: 25(OH)D3 was quantified in 112 ocular samples. In 40 cataract patient samples, the average 25(OH)D3 concentration was 0.057 ng/mL, compared to 72 retinal disease patient samples, average of 0.502 ng/mL (p < 0.001). Intraocular 25(OH)D3 did not correlate with serum levels of 25(OH)D3. There was no difference between the level of 25(OH)D3 measured in the aqueous and vitreous humour. The vitamin D-specific CYPs 27B1 and 24A1, strongly localized to complementary regions of the ciliary body, retinal pigment epithelium and neural retina. Gene expression analysis confirmed retinal CYP27B1 correlated strongly with VEGF-A in eyes from diabetic patients (r = 0.92, p < 0.001). CONCLUSIONS: Our data confirms that vitamin D is present in the humours of the human eye and that local synthesis/degradation is possible via the ocular CYP27B1 and CYP24A1. This argues for a functional role for local vitamin D production and signaling in the eye and suggests that vitamin D may be an important intraocular mediator in disease pathogenesis.