Need help? Click here for instructions. All Rights Reserved Privacy Policy. Fluctuating Vision After Radial Keratotomy. Cover Focus: Debates in Refractive Surgery. Surgeons as Refractive Surgery Patients. Late complications of radial keratotomy RK can occur, and, for the newest generation of refractive surgeons unfamiliar with this type of incisional surgery, management can be challenging. The goal of this pictorial review is to enhance understanding of the common complications of RK and the rationales for several management approaches.
RK, pioneered by Professor Svyatoslav Nikolayevich Fyodorov in , first performed in Russia, and adopted by US surgeons in particular and ophthalmologists in the rest of the world in the mid to late s, was a promising technique for the correction of low myopia.
RK relied on the effect of a series of deep radial incisions to relax the peripheral and flatten the central cornea in patients with myopia. The number of incisions varied from four to 16 and sometimes ambitiously 32, depending on the level of correction required, but all incisions extended from the pupil to the corneal periphery in a radial pattern, like the spokes of a wheel.
The Russian technique was felt to be more effective with deeper incisions centrally, however, there was considerable risk of entering the visual axis. The realization that there was no need to cut to the limbus gave rise to the concept of minimally invasive RK mini-RK. Introduced by Richard L. In mini-RK, incisions extending from the 3- to the 8-mm optical zone were created, rather than the variable number of mm full-length incisions used in the standard RK technique.
I was Dr. I performed RK for a couple of years in my own practice, and for the past 27 years I have regularly looked after patients with RK-related problems. As a result, my perspective on the procedure has changed over the years. RK worked by essentially producing controlled ectasia in the periphery of the cornea. Because the cornea is an elastic dome, the periphery became elevated, and the central area flattened to produce the desired outcome of correcting myopia.
Despite their positive effects, RK incisions cause several complications and side effects over time Table. These include a progressive hyperopic shift, diurnal fluctuations in visual acuity, starbursts, ectasia, poor visual quality from increased spherical aberration, and rupture of the keratotomy scars if traumatized. Shifts, fluctuations, and starbursts.
In some cases, particularly inferotemporal, RK incisions become more ectatic over time. This is often the case in eyes that have epithelial cysts or are originally predisposed to developing keratoconus, and ectasia is sometimes exacerbated by the performance of additional corneal ablative surgery for hyperopic correction. By ablating elevated areas, this secondary intervention steepens the cornea but also thins mechanically weak tissue, thereby contributing to ectatic progression Figure 2.
Poor visual quality from increased spherical aberration. RK patients often report a deterioration in visual quality as they age.
If a patient has 24 RK incisions, I can do the entire bimanual procedure through two 1-mm incisions that are fit in between the RK incisions. According to Dr. In the postoperative period, surgeons and patients should be prepared for swelling of the RK incisions.
The surgeon is distraught, but this is actually OK. On postop day one, just put the patient back in that same machine and do K measurements. The patient will typically be Then, two weeks or a month out, the postop K value is back to 36, the swelling has resolved and the patient is plano. Additionally, Dr. Always choose the higher lens power, and let the patient end up It will only stay Hoffman adds that there is a greater chance for refractive surprises in post-RK eyes, so he encourages patients to have realistic expectations.
They are willing to accept a less-than-perfect result. Chang recommends asking patients how they felt about the quality of vision they had after RK but before the cataract formed. From a counseling standpoint, you have some advantages there. Hoffman prepares patients to expect a longer period for stabilization of the refraction postoperatively.
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