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Abstract #45528 Published in IGR 13-2
Decrease in intraocular pressure following orthokeratology measured with a noncontact tonometer
Ishida Y; Yanai R; Sagara T; Nishida T; Toshida H; Murakami AJapanese Journal of Ophthalmology 2011; 55: 190-195
PURPOSE: Orthokeratology for correction of myopia reduces corneal power by flattening corneal curvature and thinning central corneal thickness (CCT). Measurement of intraocular pressure (IOP) with a noncontact tonometer is known to be affected by CCT and corneal curvature. We investigated the influence of orthokeratology on such measurements of IOP. METHODS: This was a prospective, interventional case series derived from a clinical trial of orthokeratology lenses in two hospitals. Both eyes of 45 subjects were fitted with reverse-geometry lenses, worn for more than 4 h overnight for 52 weeks. Uncorrected visual acuity, refraction, IOP (with a noncontact tonometer), CCT, and corneal curvature were measured. RESULTS: Uncorrected visual acuity, spherical equivalent value, IOP, CCT, and the radius of corneal curvature were 0.93 ± 0.27, -2.87 ± 1.05 D, 13.5 ± 2.5 mmHg, 536.2 ± 39.6 μm, and 7.88 ± 0.25 mm, respectively, before orthokeratology, and 0.17 ± 0.34, -1.05 ± 1.18 D, 12.4 ± 2.7 mmHg, 528.6 ± 40.8 μm, and 8.10 ± 0.31 mm at 52 weeks after treatment. The changes in all parameters were significant, and the change in IOP was significantly correlated with that in CCT at 24 weeks and thereafter. CONCLUSIONS: Orthokeratology for myopia leads to a decrease in IOP measured with a noncontact tonometer, likely as a result of the associated decrease in CCT.
Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan.
Classification:
8.4 Refractive surgical procedures (Part of: 8 Refractive errors in relation to glaucoma)
2.2 Cornea (Part of: 2 Anatomical structures in glaucoma)
6.1.1 Devices, techniques (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)
