July 2019

CORNEA

Device Focus
Re-examining scleral lenses


by Rich Daly EyeWorld Contributing Writer


Corneal staining pattern after short-term use of a scleral lens

Limbal staining pattern after short-term use of a scleral lens
Source (all): Vishakha Thakrar, OD

 

Scleral lenses can offer a range of benefits to several types of patients, but they also carry the potential for complications.
The primary indication for scleral lens referral is the correction of vision for irregular astigmatism and corneal ectasias, said Vishakha Thakrar, OD.
“The saline between the posterior lens and anterior cornea creates a tear lens to correct vision in irregular corneas,” Dr. Thakrar said. “Commonly treated conditions include keratoconus, pellucid marginal degeneration, post-LASIK ectasia, radial keratotomy, penetrating keratoplasties, and corneal scars, dystrophies, and degenerations.”
Good candidates for scleral lenses include those with irregular astigmatism that cannot be corrected with spectacles, soft lenses, or corneal rigid gas permeable lenses, said Deborah S. Jacobs, MD. Other scleral lens candidates are patients with ocular surface disease that interferes with comfort or vision, as well as patients with regular astigmatism who are unhappy with quality of vision in spectacles and soft lenses and have occupational or recreational demands that can’t be met by corneal RGP lenses.
“That would be people who work in windy or dusty environments and athletes,” Dr. Jacobs said. “Baseball players meet both criteria. Outdoor workers of all sorts are candidates.”
Dr. Jacobs refers patients for a scleral lens trial or consultation before deciding whether to proceed with a fitting. The trial should address whether the patient’s vision improves or the lens provides support for the ocular surface, and the patient’s ability to manage the application, removal, and lens care regimen should be considered.

Other trial runs

Dr. Thakrar trials scleral lenses for keratoconus and ectasia patients prior to corneal transplantation in order to measure potential vision.
“If the vision can be corrected to 20/50 or better, we often will proceed with the lens rather than pursue surgery. However, this criterion will vary from case to case depending on the VA of the other eye and the patient’s visual needs,” Dr. Thakrar said. “Nevertheless, a contact lens refraction is necessary for many of these patients in order for the patient and surgeon to make an educated decision on whether to pursue cornea transplantation.”
Unusual indications for scleral lenses include ocular chronic graft-versus-host disease and Stevens-Johnson syndrome, Dr. Jacobs said. Other good candidates for the lenses are patients with cranial nerve VII dysfunction that is congenital, from tumor, from surgery, or post-viral.
“Often eye doctors focus on ‘fixing the lids,’ but that may be insufficient for maintenance of corneal integrity and comfort,” Dr. Jacobs said. “Patients with ‘blepharoplasty gone bad’ can be excellent candidates.”
Finally, scleral lenses can be a good solution for patients with complications after laser refractive surgery as well as those with declining and fluctuating vision after RK.
“Surgeons are often reluctant to offer this option; after all, the patients chose surgery to avoid contact lenses,” Dr. Jacobs said. “But scleral lenses correct vision wonderfully in these patient and are well-tolerated even if conventional contact lenses were not.”

Dry eye referral

A patient with dry eyes can still wear soft lenses, but when dry eye worsens, patients can become intolerant to soft lenses.
“That’s where the scleral lens can fit in nicely because the scleral lens holds a reservoir of fluid that bathes the corneal tissue, potentially treating dry eye while they are wearing the lens,” said William Trattler, MD.
Dr. Jacobs refers dry eye patients for scleral lenses when there is a surface breakdown that has not responded to medical management including OTC and prescription topical agents, treatment of meibomian gland issues, and punctal occlusion, or if there are lid issues that are not easily or completely addressed with surgery.
“Patients with dry eye discomfort but excellent vision in glasses or contacts may not be happy with the logistical demands of scleral lens wear and may have issues with the quality of vision related to surface wetting issues that can arise,” Dr. Jacobs said. “Patients with neuropathic eye pain respond variably, with better results in patients in whom signaling is peripheral and not longstanding.”

Scleral lens complications

The leading complication for these devices occurs in corneal transplant patients, said Elise Kramer, OD.
“If patients have a low endothelial cell density or they don’t have healthy endothelial cells, they will develop corneal edema,” Dr. Kramer said.
Another complication stems from uncertainty around the effects of ocular pressure, which has led clinicians to avoid giving the lenses to patients with ocular hypertension.
When there are complications, the alternatives to scleral lenses are determined by the condition. In the case of ocular surface disease, no other type of lens can replace what the scleral lens has to offer the surface of the eye, Dr. Kramer said.
But in the case of keratoconus or an irregular cornea, other options include hybrid lenses, small rigid lenses, and soft lenses.
Cases of lens fogging can be easily troubleshot by improving the lens fitting, Dr. Kramer said.
“If they are developing irritation or fogging with the lens it’s probably because the lens is not fitting properly,” Dr. Kramer. “Where the lens is landing it can cause fogging because it’s putting pressure on the tissue, and it can also cause irritation for the same reason.”

About the doctors

Vishakha Thakrar, OD
Private practice
Vaughan, Ontario

Deborah S. Jacobs, MD
Associate professor of ophthalmology
Harvard Medical School
Boston

William Trattler, MD
Center for Excellence
in Eye Care
Miami

Elise Kramer, OD
Private practice
Miami

Contact information

Kramer
: elise@miamicontactlens.com
Jacobs: deborah_jacobs@meei.harvard.edu
Thakrar: thakrarv@gmail.com
Trattler: wtrattler@gmail.com

Financial interests

Kramer: BostonSight Scleral, Euclid Systems Corporation
Jacobs: None
Thakrar: Bausch + Lomb, Precision Technology
Trattler: None

Re-examining scleral lenses Re-examining scleral lenses
Ophthalmology News - EyeWorld Magazine
283 110
220 297
,
2019-07-01T08:29:19Z
True, 7