Ortho-K was indicated for sixty eyes of thirty aviators, twenty-one pilots and nine flight attendants, with age of 34.5 on the average. Uncorrected visual acuity (UCVA) was originally 20/30 or worse in all cases. The mean spherical equivalent (SE) was -3.69 Diopters (D). The same ophthalmologist designed full costumed reverse geometry Advanced Orthokeratology lenses for each patient. All the patients were followed at least two years wearing of Advanced Ortho-K lenses. The follow up examinations on auto-refraction, auto-keratometry, uncorrected and corrected visual acuity, intra-ocular pressure, corneal endothelial cells, corneal thickness and curve, and corneal shape were performed in the morning, 10am to 12am.
94% of the patients improved in UCVA up to 20/20 or better, 87% of them improved up to 20/15 or better, and 67% of them improved up to 20/10. The mean SEs improved to -1.90±1.00D during six months, -1.49±1.03D during one year, and -0.73±0.94D during two years. Astigmatism slightly increased by 0.38D on the average, however, it did not cause any serious problems for aviation tasks even during night. Intraocular pressure did not increase and corneal endothelial cells did not decrease. Other ophthalmologic examinations showed normal conditions and any complications were not observed throughout the period.
Advanced Ortho-K was evaluated to be safe and effective enough for also aviators with myopia. It can be recommended one of the options of reduction of myopia for aviators. Evaluations on night vision and night glare are planned for further studies.