Initial Visual Management of Orthokeratology Patients
BY CRAIG W. NORMAN, FCLSA
One of the more perplexing issues we incur during the off-label overnight orthokeratology fitting process is the management of daytime vision during the first few days of treatment. Typically, patients wear these lenses during their first night after dispensing, then return to the office early the next morning with the lenses still on the eye. After the practitioner evaluates visual acuity with the lenses on, he evaluates the lens fit by both white light and fluorescein pattern. The lenses are removed, uncorrected vision is tested, corneal integrity examined and then keratometric measurements and, most importantly, topographical mapping takes place. Usually, the practitioner then decides to modify the lens fitting relationship or continue with the same lenses for orthokeratology treatment.
The question patients ask most often is, "What do I do if my vision begins to change during the day?" First, remind patients that their current glasses won't work. Then discuss the two widely used, yet quite different approaches to answering this question.
One approach is to consider wearing daily disposable (single-use) soft lenses on a temporary basis. For example, if a slow-responding 4.00D myope has a first night corrective effect of 2.00D resulting in 20/200 uncorrected vision, he will need a lens to correct the remaining 2.00D until the practitioner determines if the lens fit is adequate or not.
We can expect in this case that for the first few days that the patient will need additional correction. Dispensing a series of disposable soft lens (2.00D, 1.00D, 0.50D, etc.) may provide the patient with the necessary correction until the endpoint orthokeratology effect is achieved.
Soft daily disposable lenses are readily available in the office and can be easily dispensed to the patient. Unfortunately, this is a cumbersome method since it entails additional lenses, possibly more (and different) training for insertion and removal and will not correct any remaining corneal astigmatism. Also, the patient is modulating his correction instead of the practitioner.
Daytime Visual Options During Orthokeratology Adaptation
In our clinic, we prefer to simply have the patient wear his ortho-k lenses for daytime wear once his uncorrected vision changes enough to bother him. This may be at noon, 4 pm or 8 pm, depending on individual patient response. This method provides crisp vision, corrects for residual corneal astigmatism and doesn't require a separate contact lens modality. Plus, it aids in achieving the treatment effect with additional wearing time.
Our experience is that these reverse geometry lenses are very comfortable and easy for the patient to wear during daytime hours. After the first few days of treatment, it usually isn't necessary for the patient to be concerned with this auxiliary lens use, but it is a great option during the adaptation period.
Some practitioners prefer that patients wear their lenses during the day for the first few days during adaptation. The rationale behind this concept is that it aids in initial ortho-k changes, helps the patient become adept at lens handling and provides clear acuity during the daytime.
Craig W. Norman is Director of the Contact Lens Section at the South Bend Clinic in South Bend, Indiana. He is a fellow of the Contact Lens Society of America and an advisor to the RGP Lens Institute.