Aqueous Humor Cytokine Response in the Contralateral Eye after First-Eye Cataract Surgery in Patients with Primary Angle-Closure Glaucoma, High Myopia or Type 2 Diabetes Mellitus.

BACKGROUND

Bilateral sequential cataract surgery within a short period is becoming more prevalent because of the efficiency and safety of modern cataract surgery. It has been reported that the first surgical eye might affect the contralateral eye. This study investigated the cytokines involved in the immunopathogenesis of pre-existing ocular or systemic conditions, as well as the inflammatory biomarkers in response to topical stimuli, by analyzing the cytokine profile of aqueous humor (AH) from cataract patients without these morbidities as control and with type 2 diabetes mellitus (DM), primary angle-closure glaucoma (PACG) or high myopia (HM) in each eye at the beginning of first (defined as baseline) and second eye cataract surgery.

METHODS

Forty patients were recruited in this cohort study (10/group). Bilateral sequential cataract surgeries were conducted at intervals of 12.08 ± 1.2 days. Aqueous humor samples (100-200 μL/eye) were separately collected from 40 first-eyes and 40 second-eyes at the beginning of the cataract surgeries. Twenty-seven selected cytokines were detected with Luminex-multiplex immunoassay. The concentrations of cytokines in the aqueous humor and their association with pre-existing ocular or systemic conditions were analyzed and compared between and within the groups.

RESULTS

Before first-eye surgery (baseline), the levels of interleukin (IL)-1ra, IL-13 and tumor necrosis factor (TNF)-alpha were significantly increased in PACG compared with controls. The levels of IL-13 were increased while that of IL-15 were decreased in HM. Compared with controls, 11 cytokines were significantly increased in DM. In the AH of the contralateral eye after first-eye cataract surgery, basic fibroblast growth factor (bFGF) was significantly more abundant in PACG and HM, while the levels of monocyte chemoattractant protein-1 (MCP-1) and interferon gamma-induced protein 10 (IP-10) were decreased in PACG. We also identified 6 significantly upregulated cytokines in DM compared with controls. Compared with baseline, there was an overlap of 5 altered cytokines in the AH of contralateral eyes after first-eye surgery between the four groups. Some were exclusively altered in each subgroup, with 1 in the control group, 4 cytokines in the PACG and HM groups, and none in the DM group.

CONCLUSIONS

From the initial profile, it is observed that patients with pre-existing ocular or systemic conditions have some degree of inflammation in their eyes before surgery and in the contralateral eye after the first eye cataract surgery, which could be peculiar of the morbid conditions of the patients. Inflammation was more detectable in patients with type 2 DM before surgery. PACG and HM patients showed stronger intraocular inflammatory reactions to topical stimuli compared with controls and DM patients. Our data suggest that ophthalmologists should pay closer attention to inflammatory responses, especially in cataract patients with pre-existing conditions, although the clinical significance of these changes following surgery remains to be further investigated.