Abstract
Purpose :
Ischemic retinopathies encompass conditions like central retinal artery occlusion (CRAO) and diabetic retinopathy (DR), which involve acute or chronic retinal ischemia, respectively. CRAO can lead to severe vision loss, with less than 20% of patients regaining functional visual acuity in the affected eye. DR remains the leading cause of blindness in working-age adults. Studies suggest that proteins in ocular fluids reflect retinal pathology. This study conducts a proteomic analysis of aqueous humor (AH) samples from CRAO patients and vitreous humor (VH) samples from DR patients undergoing pars plana vitrectomy (PPV).
Methods :
AH samples were collected from 10 CRAO patients undergoing standard-of-care paracentesis and 10 controls undergoing cataract surgery. VH samples were collected from 10 DR patients and 10 non-diabetic controls undergoing PPV. Samples were analyzed using an Orbitrap Eclipse Tribrid mass spectrometer.
Results :
Compared to controls, AH levels of 36 differentially expressed proteins (log fold change, logFC > |1|, q-value < 0.05) were identified in CRAO patients. Qiagen IPA analysis revealed 11 proteins linked to ophthalmic diseases. Notably, gamma enolase, a glycolysis enzyme isoform primarily expressed in neurons, was upregulated (logFC = 1.2, q-value = 0.018), suggesting neuronal injury and enzyme release. Additionally, clusterin, a known protective protein, was downregulated (logFC = -1.8, q-value = 0.006). ELISA confirmed proteomics data. VH samples from DR patients exhibited changes in a distinct set of proteins, including ones previously reported in the literature.
Conclusions :
This study presents the first proteomic analysis of AH samples from CRAO patients. Multiple hits with potential implications for CRAO pathophysiology and management were identified. Proteomic results differed between DR and CRAO studies, likely due to the differing pathophysiology and disease duration.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.