Stability of wavefront aberrations during the daytime after 6 months of overnight orthokeratology corneal reshaping.

Abstract

PURPOSE:

To evaluate the stability of wavefront aberrations during the daytime after 6 months of overnight orthokeratology corneal reshaping.

METHODS:

A prospective study of 26 eyes using the Ultravision BE lens design during 6 months of overnight wear. Uncorrected visual acuity (UCVA), cycloplegic refraction, and wavefront aberrometry were measured at 8 AM (within 1 hour after awakening and removing lenses), 1 PM (5 to 6 hours after lens removal), and 6 PM (10 to 12 hours after lens removal).

RESULTS:

There was no significant difference in UCVA between 8 AM, 1 PM, and 6 PM (P=.383). Spherical power from wavefront aberrometry showed significant regression from 8 AM to 1 PM (P<.001) and stabilized near zero diopters. Total root-mean-square (RMS) increased and higher order aberration RMS and defocus (Z4) decreased between 8 AM and 1 PM (P<.001) but did not change for the rest of the day (P>.001). There was no statistically significant change in astigmatism (Z3 and Z5) (P=.449) and coma (Z7 and Z8) (P=.145) between 8 AM, 1 PM, and 6 PM. Spherical aberration (Z12) showed regression throughout the day (P<.001).

CONCLUSIONS:

After 6 months of overnight orthokeratology wear, some optical aberrations showed regression during the day. Despite no significant change in UCVA during 10 to 12 hours, there was a significant increase in defocus (Z4) within the first 5 hours after removing the orthokeratology lens and a decrease in spherical aberration (Z12) throughout the day.

• Authors: Iane Stillitano, Paulo Schor, Cesar Lipener, Ana Luisa Hofling-Lima
• Journal: Journal of refractive surgery (Thorofare, N.J. : 1995) (J Refract Surg) Vol. 23 Issue 9 Pg. 978-83 (Nov 2007) ISSN: 1081-597X [Print] United States
• PMID: 18041257 (Publication Type: Journal Article)

Topics

• Circadian Rhythm
• Corneal Topography
• Diagnostic Techniques, Ophthalmological
• Fixation, Ocular
• Humans
• Orthokeratologic Procedures
• Prospective Studies
• Refraction, Ocular
• Refractive Errors (diagnosis, physiopathology, therapy)
• Time Factors
• Visual Acuity