Healio: radial keratotomy eyes hyperopic postop
- Healio on April 16 reported that cataract surgery in eyes with prior radial keratotomy can leave patients temporarily farsighted after surgery, even when lens calculations are correct. - Uday Devgan said the early hyperopic shift comes from fluid swelling old radial cuts, flattening the cornea; surgeons should usually target mild myopia and wait. - The issue affects aging radial keratotomy patients because long-term corneal flattening already pushes many toward hyperopia before cataracts develop. (aao.org)
Radial keratotomy was an older vision-correction surgery that used deep spoke-like cuts in the cornea to flatten its center and reduce myopia. Those cuts can still change the cornea decades later, which is why cataract surgery in these eyes is unusually hard to predict. (healio.com) (aao.org) Healio reported April 16 that patients with prior radial keratotomy can develop a temporary hyperopic, or farsighted, shift after cataract surgery even when the intraocular lens calculation was reasonable. Uday Devgan wrote that the early result can look like a refractive miss before the eye settles. (healio.com) The mechanism is mechanical, not mysterious. During cataract surgery, balanced salt solution and instrument manipulation can hydrate the old radial incisions, and swollen cuts flatten the central cornea enough to push vision in a hyperopic direction for the first weeks. (healio.com) (aao.org) That is why post-radial keratotomy cataract cases are often planned with a little extra lens power, aiming for mild myopia instead of exact plano. Devgan wrote that a small nearsighted result is usually easier to tolerate than another hyperopic surprise. (healio.com) The challenge starts before the operating room. Standard keratometry can miss the flattest central zone in a post-radial keratotomy cornea, which can underestimate corneal power and point surgeons toward an intraocular lens that is too weak. (healio.com) (aao.org) The American Academy of Ophthalmology says these eyes also need extra follow-up because the early hyperopic shift can last long enough to mislead both surgeons and patients. Its 2021 guidance recommends at least three months of follow-up before treating the first postoperative refraction as stable. (aao.org) There is a longer arc behind that warning. The National Eye Institute’s 10-year Prospective Evaluation of Radial Keratotomy results said 43% of eyes shifted at least 1 diopter in the hyperopic direction between six months and 10 years after the original radial keratotomy. (nei.nih.gov) (jamanetwork.com) That means many cataract patients who had radial keratotomy in the 1980s or early 1990s arrive for surgery with a cornea that is already flatter, less stable and harder to measure than a routine eye. The same old incisions that once reduced myopia are now part of the cataract calculation problem. (healio.com) (aao.org) The practical message is less about a new device than about expectations. In post-radial keratotomy eyes, a farsighted result on day one may be a stage of healing, not the final answer. (healio.com) (aao.org)
