LONG AXIAL LENGTH IS A RISK FACTOR FOR INFECTIOUS ENDOPHTHALMITIS IN MICROINCISIONAL VITRECTOMY AND MEMBRANE PEELING SURGERY.

Abstract

To investigate risk factors of infectious endophthalmitis (IE) in microincision vitrectomy surgery and membrane peeling. The authors retrospectively reviewed the medical records of patients who underwent microincision vitrectomy surgery and membrane peeling for idiopathic and secondary epiretinal membranes. IE incidence and its causative microorganisms were collected. Risk factors for IE development- including age, sex, simultaneous cataract surgery, axial length, refractive error, intraocular pressure, myopic tractional maculopathy (MTM), and diabetes mellitus-were assessed. Main outcome measures were association between IE development and clinical factors. Of 3,496 eyes, IE occurred in 16 eyes (0.45%). The causative microorganisms were detected in 12 eyes (75%) showing Staphylococcus epidermidis (n = 9), Staphylococcus aureus (n = 1), Staphylococcus capitis (n = 1), and Enterococcus faecalis (n = 1). More IE developed in female (0.74% vs. 0.12%, P = 0.01), eyes with MTM (5.0% vs. 0.35%, P = 0.001), and high myopia (1.7% vs. 0.34%, P = 0.001). Mean axial length (25.2 ± 3.0 vs. 24.0 ± 1.8 mm), mean age (67.4 ± 8.0 vs. 62.4 ± 12.2 years), simultaneous cataract surgery (0.54% vs. 0.27%), and presence of diabetes mellitus (18.7% vs. 20.9%) were not different between eyes with and without IE. High myopia and MTM were significantly associated with IE (logistic regression; P = 0.009, P = 0.046, respectively). Eyes with MTM (n = 80) and high myopia (n = 294) exhibited significantly lower intraocular pressure on Day 1 (11.2 ± 4.6 mmHg and 12.0 ± 5.1 mmHg, respectively), compared with age-matched controls (13.9 ± 4.3 mmHg and 13.6 ± 4.4 mmHg; P = 0.001 and P = 0.01, respectively). In microincision vitrectomy surgery and membrane peeling, eyes with high myopia and MTM, which were likely to have lower intraocular pressure in the early postoperative period, were more susceptible to postoperative IE.