gms | German Medical Science

102. Jahrestagung der DOG

Deutsche Ophthalmologische Gesellschaft e. V.

23. bis 26.09.2004, Berlin

Long-term changes of orthokeratology lens wear: visual and corneal changes

Meeting Abstract

  • corresponding author N. Stübiger - Department of Ophthalmology, University of Tuebingen and University of Applied Sciences Aalen
  • K. Häussler - University of Applied Sciences Aalen
  • B. Hard - University of Applied Sciences Aalen
  • R. Michels - University of Applied Sciences Aalen

Evidenzbasierte Medizin - Anspruch und Wirklichkeit. 102. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft. Berlin, 23.-26.09.2004. Düsseldorf, Köln: German Medical Science; 2004. Doc04dogDO.08.10

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dog2004/04dog077.shtml

Published: September 22, 2004

© 2004 Stübiger et al.
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Outline

Text

Objective

Overnight orthokeratology (Ortho-K) is a method for temporarily eliminating myopia. A special geometry of rigid gas permeable (RGP) lenses (double reverse back curve) enables transformation of the cornea to a flatter form. Possible diopteric corrections are lasting from -0.75 diopter (D) to -4.5 D. The aim of our study was to evaluate the effectiveness of Ortho-K for treatment of myopia and to evaluate possible pathologic corneal alterations.

Methods

The study was performed with a group of 20 volunteers. Both eyes were fitted with Ortho-K lenses, and uncorrected visual acuity, refractive correction, corneal curvature and corneal changes, including measurements of corneal endothelial alterations, were achieved. The control group consisted of 5 volunteers, who have worn glasses as vision correction. Neither group exhibited any eye disease or any pathological symptom at the beginning of the study.

Results

Before fitting the Ortho-K lenses, the wearing group had a mean spherical correction (oculus dexter/oculus sinister) of -2.06 / -2.25±0.90/0.84 D, a mean uncorrected vision of 0.64±0.31 (visus logmar) and a mean central corneal radius of 7.78 / 7.77±0.31/0.30 mm. After one week of wearing contact lenses the majority of the volunteers had such a good response, that no statistical difference in visual acuity between the two groups was detectable (the mean spherical correction was +0.14 / 0.02±0.25/0.14 D, the mean uncorrected vision was -0.12±0.06 D and the mean central corneal radius was 8.09 / 8.08±0.35/0.34 mm). Corneal irritations which occurred at the beginning of the study in the wearing group included corneal staining (40%), acute corneal edema (10%), microcystes (5). The study was completed after a mean observation period of 4 months.

Conclusions

Overnight orthokeratology, perhaps as an alternative to refractive corneal surgery, is a very safe method for temporarily eliminating minor myopia. We achieved in our study stable remaining visual changes for all walking hours of the day, which allow patients enjoy excellent device-free vision.