To examine how breath-hold diving activities of Korean haenyeo female divers affect intraocular pressure (IOP), optic nerve and visual field (VF).

Basic ophthalmologic tests were performed for a group of breath-hold female divers (26 eyes) and a control group of non-divers (26 eyes) and the results compared between the 2 groups. For the breath-hold female diver group, a questionnaire survey was conducted on the patterns of breath-hold diving and the correlation with abnormalities in IOP, optic nerve and VF analyzed.

IOP was significantly higher in the diver group (diver group: 15.00 ± 3.76 mm Hg, control group: 13.93 ± 2.36 mm Hg, p < 0.05). Between the 2 groups, the cup area (diver group: 1.21 ± 0.60 mm², control group: 0.83 ± 0.46 mm² , p < 0.05), the cup-to-disc (C/D) ratio (diver group: 0.44 ± 0.21, control group: 0.31 ± 0.14, p < 0.05), and the vertical C/D ratio (diver group: 0.70 ± 0.17, control group: 0.51 ± 0.12, p < 0.05) were also significantly different. A significant correlation between working hours per day and IOP (r = 0.44, p < 0.05), between diving depth and RNFL defect, and cup area, and vertical C/D ratio (r = 0.43, r = 0.41, r = 0.39, p < 0.05) was observed.

Subjects who breath-hold dive for a long period, such as Korean Haenyeo, need to have a glaucoma test regularly.