Article

CLINICAL: CONTACT LENSES

FITTING SCLERAL LENSES

Realize the benefits of this technology in post-surgical patients

Post-surgical patients can have some of the most challenging corneas to fit with contact lenses. This due to their often irregular shape. But, with today’s scleral lens technology, which vaults the cornea, our patients can achieve optimal comfort and vision after their procedures. Here’s a case study and a look at the fitting process.

KERATOCONUS PATIENT

A 46-year-old female with keratoconus in both eyes who had a corneal transplant OS, presented for a comprehensive exam. Her history showed an inability to wear contact lenses in the past due to discomfort and irritation. She told me she was open to the idea of wearing contact lenses again, but was concerned with her past failures. Her spectacle prescription was: -5.25 – 1.25 x 005 OD and -3.00 – 2.50 x 024 OS with a +2.25 add OU. Her BCVA was 20/20- OD and 20/25- OS.

After discussing her options, I proceeded with a scleral contact lens fit. Scleral lenses were the best option to provide a smooth optical surface, without putting stress on the cornea, by vaulting her irregular corneal shape. (When fit correctly, this option will maximize comfort and provide the best visual outcomes.)

Topography can give the eye care practitioner a starting point for the amount of irregularity that is needed to correct during a scleral lens fitting.
Image courtesy of Jason Miller, O.D., M.B.A., F.A.A.O.

FITTING PROCESS

To improve your confidence with scleral lenses, consider attending a fitting workshop, certification courses or a training session online with the lens manufacturer.

To determine the best scleral lens for this patient, I followed these three steps:

  1. Ensure clearance. Utilizing a fitting set, I was able to obtain my primary goals for this patient. After placing a variety of lenses on her eyes, the proper lens allowed about 250 μm of central corneal clearance. This can be seen with a narrow beam (optic section) behind the slit lamp or with an anterior segment OCT image.
  2. Clear the limbus. Fluorescein helps visualize the limbus to ensure the limbal stem cells are not being stressed by the lens. (If changes need to be made, I utilize the fit guide, or call the manufacturer of that specific scleral lens for troubleshooting.)
  3. Stick the landing. As a 16 mm-diameter lens cleared the limbus on this patient, I now needed to make sure it landed correctly on the sclera to be comfortable for the patient and not cause any impingement of the conjunctival tissue. Use of the slit lamp can reveal blanched or ghost blood vessels along the limbus due to a poor landing. (Again, follow the fit guide, or call the manufacturer for any troubleshooting here.)
    Keep in mind that new technologies, such as AS-OCT, can help visualize the vault of the cornea. (There is more to come in this area.)

NEXT STEPS

It’s important to understand the science and have a plan for these specialty patients. With the help of a scleral lens, the patient discussed reported her best vision to date: 20/25+ OD and 20/30 OS.

Scleral lenses have the ability the help patients who have irregular corneas after surgery. Take the necessary steps to fine-tune these fitting skills, as this technology has the ability to vault the practitioner’s contact lens skills to a higher level. OM