Purpose: To evaluate the effect of hyperbaric oxygen therapy (HBOT) on central corneal thickness (CCT), intraocular pressure (IOP), and the retinal nerve fiber layer (RNFL) thickness in patients with type 2 diabetes mellitus. Methods: This prospective non-randomized cohort study consisted of type 2 diabetes mellitus patients who received 30 sessions of HBOT for diabetic foot ulcer. The CCT, IOP, and RNFL measured at baseline, after the 10th session of HBOT, after the 20th session of HBOT, after the 30th session of HBOT, and after the 3 months of the last session of HBOT. We gained the superior-nasal, superior-temporal, inferior-nasal, inferior-temporal, nasal and temporal quadrant RNFL values with a spectral-domain optical coharence tomography. Results: Forty-six eyes of 46 patients included in the study. During the study period, a statistically significant increase in mean IOP values compared to baseline was observed (p < 0.001). We found no significant changes at CCT and all quadrants of RNFL values during HBOT and after 3 months of the treatment (p > 0.05). During the study period, the IOP levels increased over 21 mmHg (between 22 and 28 mmHg) in seven eyes (15.2%). The mean hemoglobin A1c values of these patients with IOP >21 mmHg were 8.2 ± 0.9 mg/dL, and there was significant differences compared with those of patients with IOP values ≤21 mmHg (7.4 ± 2.8 mg/dL) (p = 0.001). Conclusions HBOT increase IOP in type 2 diabetic patients especially in ones with impaired blood glucose regulation. However, it does not cause any changes in CCT and RNFL. As diabetic retinopathy and diabetic foot ulcer are in common pathologies, thus this brief report concludes a need for further studies with longer follow-up periods to explore the potential interaction of HBOT on CCT, IOP, and RNFL.

Purpose: We sought to determine changes in the conjunctival bacterial flora and antibiotic resistance after topical antibiotic drops for infection prophylaxis were administered following intravitreal injections in patients with type 2 diabetes. Methods: This prospective and nonrandomized cohort study included 116 eyes of 116 treatment-naive patients with type 2 diabetes who received six serial intravitreal anti-vascular endothelial growth factor injections for macular edema. Three conjunctival cultures were obtained from each eye over the course of the study (Culture 1, baseline; Culture 2, 1 month after the third injection; and Culture 3, 1 month after the sixth injection). The study subjects were given topical moxifloxacin hydrochloride for 4 days after each monthly intravitreal injection. The growth patterns of conjunctival bacterial flora and the antibiotic resistance to several commonly used antibiotics were examined. Results: The rate of culture positivity increased significantly during the observation period (Culture 1, n = 47, 40.5%; Culture 2, n = 58, 50%; Culture 3, n = 76, 65.5%, p < 0.001). The bacterium with the highest baseline culture positivity was Staphylococcus epidermidis (n = 45, 38.8%), which increased significantly during the observation period (p < 0.001). No significant increase was noted in the culture positivity of the other bacteria with baseline culture positivity (p > 0.05). Regarding antibiotic susceptibility, significant increases in resistance to the fluoroquinolone group of drugs were noted (p < 0.001). No significant changes in sensitivity were detected in the other 11 investigated antibiotics that are commonly used in clinical practice (p > 0.05). Conclusions The use of topical moxifloxacin after each intravitreal injection significantly increases the fluoroquinolone resistance of the ocular surface flora and the culture-positivity rate of S. epidermidis in patients with type 2 diabetes.