Refractive surgery follow-up

Refractive: Back to basics
September 2022

by Liz Hillman
Editorial Co-Director

With advanced screening parameters and improved surgical techniques and technologies, the follow-up for refractive surgery—whether it be corneal or lenticular-based refractive correction—has become routine and, in most cases, fairly uneventful. But EyeWorld caught up with Kathryn Hatch, MD, and Gregory Parkhurst, MD, for a refresher and some important things to remember in the short- and long-term follow-up with post-refractive patients.

EVO Visian ICL
The first arrow shows the vault of the EVO Visian ICL over the crystalline lens. The second arrow shows the central port of the EVO Visian ICL.

In general, Dr. Parkhurst said, regardless of the refractive surgery performed, in the early postop period, the surgeon is looking at unaided vision at the target that was selected for the treatment. He added that most refractive surgery patients are myopic and being corrected for distance vision. In presbyopia patients who have received refractive surgery, Dr. Parkhurst said distance, intermediate, and near is evaluated. Patients in all cases are also counseled to make sure they are compliant with appropriate postop instructions (prophylactic antibiotic drop and steroid use, artificial tears, wearing shields/googles, etc.).

Dr. Parkhurst said long-term, annual follow- up of post-refractive patients is important to monitor the success of their refractive surgery but also because previously myopic eyes are more at risk for other ocular comorbidities unrelated to the refractive surgery.

“Just because we’re able to correct a refractive error in the cornea of a myope, we’re not making their otherwise myopic eye anatomically non-myopic,” he said. “We know that myopes are at risk for other unrelated ocular pathology; specifically, we know that high myopes have greater risk for retinal issues including retinal tears, retinal detachments, and glaucoma is more prevalent in high myopes as well as cataracts. Additionally, highly myopic eyes have risks for other comorbidities, and those things need to be monitored for even if they’ve had their refractive error treated.”

Corneal refractive surgery

As with any surgery, Dr. Hatch said corneal refractive surgery (LASIK, SMILE, and PRK) has an acute healing phase early on, and long-term follow-up is advised to monitor for stability. If a patient experiences issues such as dry eye, visual changes, or a need for a second procedure such as an enhancement, they should be monitored and treated, if necessary. Dr. Parkhurst noted the importance with corneal procedures to look for DLK at the interface and treat it if observed.

EVO Visian ICL
EVO Visian ICL vault of approximately 100% of central corneal thickness
Source (all): Roberto Saenz, OD

Dr. Hatch said she sees patients at postop day 1 and, if they look good, patients will come back at postop week 1. From there, she’ll see them at 6–8 weeks and once or twice again in the first year. With PRK patients, she’ll see them also at postop day 4 to remove the bandage contact lens and postop week 2 for a pressure check because they’re on a longer course of steroids.

On an annual or biannual basis, Dr. Hatch said she likes to see patients to check on their general eye health (sooner if the patient experiences changes in vision), including topography measurements.

“As a general practice, I think it’s good for all patients after keratorefractive surgery to not only have baseline topography but serial follow- up scans such that if they were to develop a change, you’d know,” Dr. Hatch said. “I think that’s often what is lacking when I get a referral for patients with ectasia. I don’t typically have prior topographies.”

In general, Dr. Hatch said if a post-refractive surgery patient develops ectasia, they are presenting to her once they’ve had vision changes, and from there she recommends collagen crosslinking right away.

“This is different from keratoconus,” she said. “I imagine if they were followed on a regular basis, we would see it on the topography before they had vision changes. A lot of refractive surgery patients don’t follow up. They’re doing well and don’t get eye exams. … Part of it is education for patients. They should be told they need to have an eye exam once a year or every other year. We’d probably find these rare cases of ectasia sooner than the way they’re coming with full blown vision changes.”

Dr. Hatch said that post-refractive surgery ectasia has become rare due to current preop screening procedures.

“We’re so knowledgeable about residual stromal bed and respecting the amount of tissue we’re removing, obtaining genetic testing when available, as well as discussing habits such as eye rubbing,” she said.

She also said that she incorporates epithelial thickness mapping into her preop evaluation, helping her recognize early signs of abnormalities or pre-keratoconic eyes. Genetic testing can be helpful in ruling out patients who might otherwise be at risk for ectasia.

Dr. Hatch said that educating patients about the detriment of eye rubbing is generally under emphasized.

“When I see patients who have ectasia, the vast majority of them are eye rubbers or they’re sleeping with their face in the pillow. It’s one of the first questions I ask people with ectasia. It’s a surprisingly common link,” she said.

Dr. Parkhurst also said that long-term complications from corneal laser vision correction done in good candidates are rare. The benefit of doing an annual exam in these patients is not so much to monitor for post-refractive ectasia but to ensure the long-term satisfaction with their procedure. He said most patients get corneal refractive surgery before becoming presbyopic. After the onset of presbyopia a decade or so later, they sometimes think the LASIK has “worn off.”

“Part of the utility of the annual exam is to reeducate the patient about the difference between myopia and presbyopia and offer solutions to that when it presents instead of trying to reeducate the patient that it’s not their LASIK wearing off,” Dr. Parkhurst said.

Phakic IOLs and RLE

For intraocular procedures like refractive lens exchange (RLE) and ICL surgery, Dr. Parkhurst and Dr. Hatch said that the postop period is similar to that of cataract surgery, with some differences.

Dr. Parkhurst said the surgeon is looking at centration of the ICLs and making sure everything is healing as expected. Visual acuity, IOP, the incision, and anterior chamber are all assessed. Within the first week, the surgeon is on the lookout for infection and aggressive inflammation as well. For phakic IOLs, the vault (space between the ICL and the crystalline lens) is assessed.

“The vault that you observe postoperatively is dependent on the size of the phakic IOL chosen. We pick ICLs relative to the power the patient needs to correct their vision; … the thing that is a little more nuanced is picking the size of the ICL that’s needed to fit in the space in the front part of the eye. The ICL comes in four different sizes, and the vault will be dependent on which of those four different lengths the surgeon chose to use.”

When monitoring vault at all visits, Dr. Parkhurst said to document it in an objective way to see if there are changes over time. If the vault was large from day 1, for example, and the IOP went up suddenly at week 1, the angle closed, the most likely diagnosis would be pupillary block and an angle closure IOP event, potentially necessitating an ICL exchange. If the vault was low/normal in the early postop period and suddenly increased later leading to angle closure, the more likely cause is obstruction of flow through the iridotomy, not the size. The newer design of the EVO Visian ICL (STAAR Surgical) with a central fenestration eliminates this latter scenario, Dr. Parkhurst said.

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Endothelial monitoring for phakic IOLs, Dr. Parkhurst said, was necessary with anterior chamber phakic IOLs. Dr. Parkhurst said a benefit of posterior chamber phakic IOLs is that they are not in close proximity to the endothelium.

“In my opinion, there is not a big utility of monitoring the endothelium with these posterior chamber lenses because chronic endothelial cell loss has not been shown,” he said.

Dr. Hatch said she will routinely check the endothelial cell count at the time of the preop workup for a phakic IOL candidate, to get a baseline. Postop, she said she will monitor it.

“It would be an unusual situation to have to explant the lens, but certainly if you see the cell count going down and there is a high vault and a situation where there is concern, you might consider explanting it,” she said, adding later that anterior segment OCT might be valuable in the postop period to assess implant vault.

Dr. Hatch offered these main takeaways for all post-refractive surgery patients regardless of the procedure: 1) do topography at all follow- up visits and 2) advise patients to not rub their eyes at all follow-up visits.


Editors’ note

Click for more specific information on EVO ICL surgery from Dr. Parkhurst’s practice.

About the physicians

Kathryn Hatch, MD
Assistant Professor of Ophthalmology
Harvard Medical School
Boston, Massachusetts

Gregory Parkhurst, MD
Parkhurst NuVision LASIK Eye Surgery
San Antonio, Texas

Relevant disclosures

Hatch: Carl Zeiss Meditec, CXLO, Glaukos, Johnson & Johnson Vision
Parkhurst: STAAR Surgical

Contact

Hatch: Kathryn_Hatch@meei.harvard.edu
Parkhurst: gparkhurst@parkhurstnuvision.com