- Limited visual acuity despite clear corneal graft.
- More frequently occurs in eyes with pre-operative keratoconus, severe scaring, or corneoscleral defect.
- Irregular suture placement, uneven suture tightness or technical error during the corneal button trephination.
- Sometimes donor astigmatism.
- Suture manipulation or removal for tension redistribution.
- May be corrected with eyeglasses or contact lenses.
- In cases where refractive corrections do not provide satisfactory vision due to high residual astigmatism, a variety of surgical options may be employed such relaxing incisions, compression sutures, excimer laser photoastigmatic refractive keratectomy or LASIK.