Navigate successful cataract surgery with refractive technology

(Image Credit: AdobeStock/ImageFlow)

With the rapid advances in surgical technologies, cataract surgery is now refractive surgery. Traditionally, cataract surgery and refractive surgery were considered separate procedures, despite many common properties. Some differences between the procedures have been that cataract surgery is medically necessary while refractive surgery is elective; cataract surgery is covered by insurance while refractive surgery is covered by the patient; and cataract surgery improves the best-corrected vision while refractive surgery improves uncorrected vision.

The surgeries have much in common. Both are outpatient procedures with relatively low risks. Both are characterized by fast recoveries and generally great outcomes.

However, the line between the 2 has become increasingly blurred due to the evolution of newer technologies that may not be covered by insurance and aim to optimize uncorrected vision after cataract surgery, said Christina Rapp Prescott, MD, PhD, associate professor of ophthalmology, residency program director, vice chair for education, and director of the Cornea Division, New York University Langone Health, New York.

Cataract surgery that is performed after refractive surgery presents unique challenges, as it is medically necessary but patients still have refractive surgery expectations, according to Prescott. Insurance covers most expenses, but patients may choose to pay for specific options.

Highlighting expectations: An illustrative case

Prescott described the case of a 73-year-old man who presented for a cataract surgery evaluation after having undergone 13 surgical procedures: bilateral hyperopic LASIK 16 years previously that resulted in epithelial ingrowth in the right eye; 2 bilateral enhancements; bilateral topography-guided photo­refractive keratectomy treatments performed in Canada; bilateral blepharoplasties; and 3 ptosis surgeries. The patient also had dry eye, suspected glaucoma, and mild cataracts. This patient was not a good surgical candidate due to irregular corneas and ultimately did well with scleral contact lenses.

“Unrealistic expectations are the No. 1 contraindication to surgery,” she said. “The best way to avoid unhappiness postoperatively is not to operate on patients [who] have a high chance of being unhappy.”

However, when avoidance is not an option, Prescott enumerated some preoperative steps to take.

Rule out other ocular pathology: Forewarned is forearmed

Predicted residual astigmatism ideally should be with the rule and less than 0.5 diopter. A toric IOL is a great option for patients with regular astigmatism but should be used with caution if there is any tomographic irregularity.

Dry eye is very common, especially post corneal refractive surgery, and should be treated preoperatively with attention paid to identifying surface irregularities, irregular astigmatism, the position and number of incisions if a refractive or arcuate keratotomy was performed, and the position and quality of the flap if LASIK was performed.

Regarding glaucoma, any visual field defects may be more noticeable after cataract surgery and could be worsened with a multi­focal lens. Optical coherence tomography can be used to screen the retina for subtle pathologies, which may cause visual aberrations post surgery.

Asking the patient about the annoyance of dirty eyeglasses and similar concerns can help clarify their expectations and personality. Other factors to consider are the patient’s occupation and the need for nighttime driving. Regarding refractive status, a patient with hyperopia or high myopia tends to have lower expectations than a patient with mild myopia or emmetropia.

Preoperative counseling

This is the time to bring all the available technology into play, such as repeat or multiple measurements, ocular surface optimization, performance of serial biometry/topography in the morning and afternoon, IOL calculators, and intraoperative aberrometry (Optiwave Refractive Analysis; Alcon). Consider a myopic target if the measurements are inconsistent. Prescott also advised discussing the various IOL options: monofocal, trifocal, extended depth of focus, toric, pinhole lenses, and a lens that can be adjusted after cataract surgery (Light Adjustable Lens; RxSight), even if the patient is not a candidate.

With these considerations in mind, Prescott described a 59-year-old man with bilateral cataracts who had a history of bilateral radial keratotomy (RK). In this case, Prescott repeated the IOLMaster/Pentacam in the morning and afternoon, used the American Society of Cataract and Refractive Surgery post-RK calculator, and considered a myopic target (progressive hyperopia).

Potential IOLs included a trifocal model that would provide the best range of vision, but this is not recommended following RK due to a high risk of optical aberrations and unpredictable refractive outcomes. IOLs such as Eyhance or Tecnis Symfony (Johnson and Johnson Surgical Vision), Vivity (Alcon), or IC-8 Apthera (Bausch and Lomb Surgical) were other possibilities.

Prescott opted for bilateral implantation of the Vivity lens. The patient achieved 20/25 at distance bilaterally and J7 and J3 in the right and left eyes, respectively. The patient occasionally used over-the-counter readers and, while slightly disappointed about needing them, was generally pleased with his vision.

A cautionary note

Regarding surgical planning for patients after RK surgery, Prescott advised creating a scleral tunnel incision, lowering the intraoperative bottle height, and being prepared to suture leaking RK incisions. When performing cataract surgery after a refractive procedure, Prescott pointed out the potential for reduced accuracy of IOL calculations.

“There is difficulty measuring the corneal power accurately, there is an altered relationship between the anterior and posterior corneal surfaces, and the effective lens position and IOL power are poorly predicted,” Prescott explained.

Many formulas and tools are available to help with prediction.

Postsurgical pearls

“Manage the ocular surface aggressively,” Prescott concluded. “More time may be required for visual stabilization. Develop a plan in case of a refractive surprise. And finally, provide reassurance to the patient.”

Christina Rapp Prescott, MD, PhD

E: christina.prescott@nyulangone.org

Prescott is associate professor of ophthalmology, residency program director, vice chair for education, and director of the Cornea Division, New York University Langone Health, New York. She is a consultant to Johnson and Johnson Vision. She presented at a New York University continuing medical education conference on current concepts of ophthalmology.