This article is more than 5 years old. Information may no longer be current.
Many points need to be considered in cataract patients with prior corneal refractive surgery
Click Here to Manage Email Alerts
I was early into corneal refractive surgery. I was honored to be selected by my friend, the late George O. Waring III, MD, to be one of the eight surgeons in the National Eye Institute-sponsored Prospective Evaluation of Radial Keratotomy study in 1980. I continued performing incisional refractive surgery throughout the 1980s and until the first excimer laser was approved in 1995. In 1987, I obtained one of the first excimer lasers and participated in the clinical trials with Taunton Technologies and later Visx, which led to FDA approval. My partners and I adopted LASIK early and have continued to have a robust laser corneal refractive surgery practice. Most of our patients were in their mid to late 30s when they requested corneal refractive surgery to correct their refractive error, and now, 30 years later, they are developing cataracts.
Management of a cataract patient with previous refractive surgery is common in our practice. I would like to share a few thoughts regarding their management. As a group, they are highly interested in refractive cataract surgery. They previously requested surgery to reduce their dependence on glasses and could afford it. They tend to be more affluent than average and, in my experience, want reduced dependence on glasses after cataract surgery and are willing to pay for it. Therein lies the challenge, as they are a more difficult patient to manage.
I will start with the RK patient. I advocated a system of RK called “mini-RK” and have published on the technique and taught it to hundreds of colleagues. In this approach, four-incision RK was favored, and more than eight radial incisions were never placed. In addition, the smallest optical zone used was 3 mm, and the incisions were stopped at 1 mm to 2 mm from the limbus. Another friend, the late Charles Casebeer, MD, and I taught hundreds of courses together, and he called this “limbal sparing RK.” If lucky enough to have a patient with cataract and this more conservative form of RK, a clear corneal incision can still be utilized, especially in the four-incision cases. In RK eyes with eight or more incisions (the most I have seen is 64) extending to or in some cases across the limbus, I recommend a scleral tunnel incision.
I usually utilize a peribulbar block when I select a scleral tunnel incision, and the classic fornix-based flap, light cautery, frown-shaped incision and dissection forward with a crescent blade reduce the risk of incisions splitting open during phacoemulsification. If incisions do split open, they usually do so near the limbus. Most of the time the cataract removal and lens implantation can be completed without placing sutures or changing the incision site. The challenge is closing the incision. I find a horizontal mattress suture at the limbus works the best, with radial sutures placed across the incision more centrally. These split-open RK incisions can be hard to close, akin to a stellate corneal laceration, and I have found that ReSure wound sealant (Ocular Therapeutix) is often a useful adjunct.
The RK eye has significant diurnal fluctuation of vision, starting more hyperopic in the morning. I like to perform a refraction at 8 a.m. and 4 p.m. Then I have a discussion with the patient as to when they wish to have the best uncorrected vision. For example, I have one patient who is a tennis-teaching professional who does all of his teaching at night. He is OK wearing glasses during the day but wants to see well from 5 p.m. to 11 p.m. Another patient might opt for best uncorrected vision in the morning. I have done corneal cross-linking on some of these patients with severe diurnal fluctuation, and it tends to dampen the fluctuation but shifts the refraction more hyperopic and the refraction can continue to change for years, so I have mixed feelings about this approach. A slightly myopic target is preferred, as the hyperopic shift these patients experience continues after surgery.
The 10-year PERK study data showed that an eight-incision RK shifts hyperopic about 1 D per decade. This must be considered in the plan and the patient counseled. They also need to be counseled that they will be blurry from a hyperopic shift caused by corneal edema on the first postoperative day and that this will clear slowly over several weeks.
I favor the IOLMaster (Zeiss) and the Barrett formulas. The American Society of Cataract and Refractive Surgery calculation website is excellent as well. Intraoperative aberrometry is difficult in the RK eye but possible after laser corneal refractive surgery.
Finally, in my opinion, multifocal IOLs do not do well in the RK patient. I have had good outcomes with so-called mini-monovision of 1 D to 1.5 D, the Crystalens (Bausch + Lomb) and the extended depth of focus Symfony IOL (Johnson & Johnson Vision), with the EDOF giving some benefit in managing the diurnal fluctuation. Toric IOLs can be utilized, but if the post-RK patient has significant astigmatism, one needs to look carefully for corneal ectasia. I cross-link the patient with post-RK corneal ectasia, and if they require a contact lens, a toric lens is avoided. In the future, I believe my IOL of choice for RK eyes will be the AcuFocus IC-8 small diameter aperture IOL, which is giving excellent results outside the United States in these difficult patients.
For me, preoperative and postoperative medication regimens are the same as in a standard case, with a little more emphasis on managing the ocular surface. Enhancements are quite common, and I prefer PRK. Patients are counseled that they are likely to need a PRK, and it could be needed again in a decade. Once again, we need morning and afternoon refractions before enhancement, as well as postoperative stability, which can take 3 months or longer. Again, the target refraction plan is made with the patient’s needs in mind as to what time of day they want to be emmetropic.
In the post-laser corneal refractive surgery patient, I still favor mini-monovision, Crystalens, and the Symfony IOL or equivalent. In patients operated more recently with PRK, LASIK or SMILE, especially if the corneal higher-order aberrations are below 0.5 RMS, a multifocal IOL can be done with good outcomes, but I remain careful here as many of the patients that I see in consultation who are unhappy with their outcomes are multifocal IOL/post-laser corneal refractive surgery patients. Because good outcomes can be obtained without using a multifocal IOL, I avoid them in most patients. In the post-PRK/LASIK/SMILE patients, I pay special attention to the ocular surface, including ocular surface preparation before surgery (I want no corneal staining), ocular surface protection during surgery, ocular surface rehabilitation and long-term maintenance. I still prefer PRK as an enhancement tool following prior PRK, LASIK or SMILE. I usually use a standard treatment based on a careful, stable and repeated manifest refraction.
Every eye care provider will be seeing more post-corneal refractive surgery patients with cataract. They are more challenging and often more demanding, requiring careful testing, planning, counseling, intraoperative skill and postoperative care, including the common need for refractive enhancements.
Disclosure: Lindstrom reports relevant financial disclosures for Alcon, Bausch + Lomb, J&J Vision and Zeiss.