APR 14, 2015
By Robert E. Fintelmann, MD, FACS
Cornea/External Disease
This comprehensive review of the latest research on refractive surgery provides guidance on which procedures may be performed with caution in patients with corneal dystrophies.
They report that phototherapeutic keratectomy (PTK) appears effective for opacities related to all epithelial and Bowman layer dystrophies, with only limited data available for both Meesmann corneal and Lisch epithelial corneal dystrophy. It has also been found to be helpful in treating decreased vision related to stromal dystrophies, with macular corneal dystrophy still eventually requiring penetrating keratoplasty.
A number of corneal dystrophies have been reported to worsen after LASIK. There is evidence that LASIK leads to an exacerbation of Avellino dystrophy and decreased endothelial cell density in Descemet membrane and endothelial dystrophies, suggesting caution in using it to correct refractive error in these patients. However, it appears to be safe after endothelial keratoplasty.
Photorefractive keratectomy (PRK) may avoid some of the complications of LASIK and be a better option for correction of ametropia in eyes with corneal dystrophies, although PRK also has been associated with exacerbation of stromal dystrophies. For endothelial basement membrane dystrophy, LASIK is contraindicated and PRK is the procedure of choice.
However, all forms of refractive surgery should be avoided in patients with granular-lattice corneal dystrophy, as they are at risk of exacerbation after LASIK or PRK. LASIK should not be performed on eyes with any evidence of guttata, and the safety of PRK has not been in established in patients with Fuchs endothelial corneal dystrophy. Both PRK and LASIK appear safe in mild forms of posterior polymorphous corneal dystrophy.
The authors stress that all patients presenting for refractive evaluation be carefully assessed for the presence of corneal dystrophies by slit-lamp examination, and asked about family history.