Efficacy of Hyperbaric Oxygen Therapy on Central Corneal Thickness, Intraocular Pressure, and Nerve Fiber Layer in Patients with Type 2 Diabetes: A Prospective Cohort Study

Abstract

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.

Oxygen-Carrying Capacity of Perfluorohexyloctane, a Novel Eye Drop for Dry Eye Disease

“… 39 No changes in the central corneal thickness were observed after 3 months of HBOT. 55 Although HBOT appears to be safe for the cornea, 2 of 8 patients showed significant increases in myopia after 20 2-hour sessions of HBOT, 39 and extended HBOT caused cataracts in guinea pigs. 56 However, HBOT involves oxygen levels that are 3.5 times more than that present in PFHO, and for a longer duration, >20 treatments of 2 hours, so it is unlikely that the oxygen in a drop of PFHO is detrimental to the eye, and indeed is likely to be beneficial as discussed above.…”

Corneal Endothelial Cell Changes After Femtosecond Laser–Assisted Cataract Surgery in Diabetic and Nondiabetic Patients

“…27 The recovery of the cornea in patients with diabetes is longer than that in normal controls. 28,29 Despite good glycemic management, corneal endothelium in diabetic patients is brittle to surgical trauma and has a weak ability to repair. 29 The eyes of patients with diabetes are subject to various metabolic changes due to hyperglycemia 19 ; the aldose reductase in diabetic patients leads to the accumulation of polyols in cells, which act as an osmotic agent causing the swelling of endothelial cells.…”