Effectiveness and safety of overnight orthokeratology with Boston XO2 high-permeability lens material: A 24 week follow-up study

• Orthokeratology is the use of rigid contact lenses to reduce refractive errors.
• Boston XO2 material with a higher Dk than the Equalens II material was examined.
• The success rate increased with length of time to 100% from day 1 to week 24.
• No severe complications were reported.

ObjectiveTo examine the effectiveness of overnight orthokeratology lenses made with Boston XO2, highly gas-permeable lens material for the temporary correction of myopia.MethodsMyopic individuals from 9 to 62 years of age were eligible. Participants ≤12 years of age were required to have myopia ≤−4.00 D and astigmatism ≤1.50 D, and for those 13–62 years of age myopia ≤−5.00 D and astigmatism ≤3.00 D. All participants were required to have normal healthy eyes and not be receiving any ocular medications or systemic medications likely to affect the results of visual acuity. Participants wore the lenses for a minimum of 7 h during sleep, and were evaluated on day 1 and weeks 1, 2, 4, 12, and 24. Success was defined as LogMAR ≤ 0.1.ResultsA total of 126 participants (63.5% females) with a mean age of 20.4 ± 11.5 years were recruited. Baseline LogMAR, and vertical and horizontal corneal curvature were 0.8, 7.7 mm, and 7.9 mm, respectively, in both eyes. A consistent decrease in LogMAR was noted from day 1 to week 12. The success rate increased with length of time (from 33.9% to 100% for the right eye and from 35.5% to 100% for the left eye from day 1 to week 24). No severe complications were noted.ConclusionOvernight orthokeratology with lenses made of Boston XO2 material are effective and safe for the temporary reduction of myopia.