Refractive surgery - Radial keratotomy

Considerations

Young applicants who undergo any type of refractive surgery for myopia before the refractive error has stabilised are at risk of recurrence of myopia, albeit to a lesser degree.

Radial keratotomy is a procedure rarely used these days being mostly limited to treating severe astigmatism. It consists in radial incisions of the cornea, allowing it to flatten.

Radial keratotomy may result in fluctuating visual acuity and sensitivity to glare. This can cause difficulties in the healing phase.

The long-term consequences of radial keratotomy are difficult to predict. Applicants should be reminded of this uncertainty as it may affect their chances of employment in the aviation industry.

Following radial keratotomy, the refraction takes time to stabilise to its new value. Flying is not permitted while the refraction is susceptible to change.

Evidence of stability generally requires:

• A waiting period since surgery of at least three months;
• A visual acuity remaining within standards for the Class sought when tested at different times, whether corrected or uncorrected;
• Absence of problem with haze, glare or contrast sensitivity.

Information to be provided

An applicant who first presents with a history of radial keratotomy should provide:

• All reports by the surgeon who undertook the procedure;
• Documentation indicating the pre-surgery refractive error;
• A special eye report, from an accredited optometrist, completed not earlier than three months post-surgery. This must include information about haze, glare, contrast sensitivity and all visual acuity and refractive error determinations done since the procedure. Measurements are to include early morning and late in the day determinations.

Note:

MEs should have a low threshold for seeking advice by the CAA in cases of radial keratotomy.

Testing of visual performance with a bright light shining at the applicant should be sufficient to demonstrate any excessive vision impairment under glare condition. A formal determination can also be done by some optometrists.

Disposition following radial keratotomy

An applicant who has undergone radial keratotomy in the past one year should be assessed as having a condition that is of aeromedical significance.

An applicant who has undergone radial keratotomy more than one year ago may be assessed as having a condition that is not of aeromedical significance if:

• The applicant meets the vision standards with or without corrections; and
• The visual acuity remains within standards for the Class sought when tested at different times, whether corrected or uncorrected; and
• There is no corneal haze; and
• There is normal contrast sensitivity; and
• The applicant does not suffer from glare.

Provided that the certificate is endorsed as follows:

• The appropriate endorsements requiring corrective lenses are applied if the standards can only be met while wearing corrective lenses; and
• Surveillance is imposed requiring yearly special eye report until five years have lapsed since surgery;
• Surveillance every five years thereafter should also be undertaken.