The Berkeley Orthokeratology Study, Part II

Comparison of Reverse-Geometry Lens Designs for Overnight Orthokeratology

“…Although small reductions in corrected acuity did also occur with ortho-k, the advantage of ortho-k over refractive surgery is that the procedure is reversible with discontinuation of lens wear. 7,16,25,26 At 1 month, the diameter of the treatment zone was larger in eyes that wore the BE lenses compared with the eyes that wore the Contex and R&R lenses. The differences in the way the lens parameters are calculated and subsequent design differences might account for the differences in the size of the treatment zone.…”

“…Subsequent attempts were all based on flat lens fitting philosophies, but took a less aggressive approach than Jessen. [3][4][5][6][7][8] Results of these early trials were unpredictable and unstable, primarily due to poor lens centration. Although the procedure appeared to be safe, unwanted corneal cylinder was often induced, 5,6,8 and only relatively small amounts of reduction in myopia were possible.…”

The Comparison of Overnight Lens Modalities (COLM) Study

“…The CRT group showed a statistically signifi- Symptoms often associated with the use of spherical orthokeratology lenses included poor visual quality, decreased distance vision, diurnal fluctuations in vision, and problems with glare. 12,13 It would be advantageous if the NEI RQL-42 could help differentiate differences between the CRT and Focus NIGHT & DAY groups for these complaints. Examining the scales on the NEI RQL-42 corresponding to these complaints found no statistically significant differences between the CRT technology and the Focus NIGHT & DAY spherical lens technology at any time during the study.…”

Orthokeratology (Corneal Refractive Therapy)

“…Four major studies were conducted by Kerns, 2 Binder et al, 3 Polse et al, 4 and Coon 5 to investigate the clinical efficacy of orthokeratology, and although they used different lens designs and fitting philosophies, all four studies reached similar conclusions. Reductions in myopia were indeed found, but they were modest (averaging approximately 1.00 D) and unpredictable and showed high individual variability.…”