Clinical Scorecard: Contact Lens Case Reports: Managing Diurnal RK Refractive Changes
At a Glance
| Category | Detail |
|---|---|
| Condition | Diurnal refractive fluctuations following radial keratotomy (RK) |
| Key Mechanisms | Corneal flattening from radial incisions causing irregular astigmatism and refractive instability, with diurnal and environmental variation |
| Target Population | Post-RK patients experiencing vision fluctuations and irregular astigmatism |
| Care Setting | Ophthalmology and optometry clinics managing post-refractive surgery complications |
Key Highlights
- Approximately 60% of RK patients experience diurnal vision fluctuations, typically shifting toward myopia, though hyperopic shifts can occur.
- Scleral lenses can provide stable vision and mitigate diurnal refractive fluctuations even in eyes with significant oblate corneal surfaces post-RK.
- Alternative management options include high-Dk soft contact lenses and corneal cross-linking, though the latter may induce hyperopic shifts.
Guideline-Based Recommendations
Diagnosis
- Assess diurnal refractive changes through manifest refractions at different times of day.
- Perform slit lamp examination to evaluate RK incisions and corneal health.
- Consider corneal topography to assess irregular astigmatism and corneal shape.
Management
- Fit customized scleral lenses to improve vision stability and reduce diurnal fluctuations.
- Consider high-Dk soft contact lenses as an alternative to stabilize refractive changes.
- Corneal cross-linking may be considered to mitigate fluctuations but monitor for hyperopic shifts.
Monitoring & Follow-up
- Regular follow-up to monitor refractive stability and corneal health.
- Evaluate visual acuity and comfort with contact lens wear.
- Monitor for potential complications such as corneal ectasia or neovascularization.
Risks
- Potential for irregular astigmatism and corneal ectasia post-RK.
- Diurnal refractive fluctuations impacting visual function.
- Hyperopic shifts associated with corneal cross-linking and some soft lens wear.
Patient & Prescribing Data
64-year-old female post-RK with 20-year history of diurnal refractive fluctuations
Scleral lenses with specific parameters (diameter, base curve, toric landing zone, high Dk material) provided stable 20/20 vision and eliminated diurnal fluctuations; glasses required switching prescriptions throughout the day when lenses were not worn.
Clinical Best Practices
- Customize scleral lens parameters to accommodate oblate corneal surfaces post-RK.
- Educate patients on the potential for diurnal refractive changes and the benefits of scleral lens wear for stabilization.
- Consider alternative contact lens modalities and adjunctive treatments based on individual patient response and tolerance.
- Monitor for and manage complications related to RK and contact lens wear.
References
- National Eye Institute. Ten-year results on radial keratotomy released. 1994
- Waring GO 3rd et al. Three-year results of the PERK Study. Ophthalmology. 1987
- Mader TH, White LJ. Refractive changes at extreme altitude after radial keratotomy. Am J Ophthalmol. 1995
- Chang V et al. Radial keratotomy: complications management. EyeWiki. 2025
- Schanzlin DJ et al. Diurnal change in refraction after radial keratotomy. Ophthalmology. 1986
- McRae S et al. Diurnal variation in vision after radial keratotomy. Am J Ophthalmol. 1989
- Inoue T et al. Minimizing radial-keratotomy-induced diurnal variation using contact lenses. J Cataract Refract Surg. 2000
- Elbaz U et al. Collagen crosslinking after radial keratotomy. Cornea. 2014
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