THE SCLERAL LENS VAULT
MANAGING PRESBYOPIA WITH MULTIFOCAL SCLERAL LENSES
GREGORY W. DENAEYER, OD
The goal of using scleral lenses to manage corneal irregularity is to maximize patients’ best-corrected distance acuity using single-vision correction. For those patients who are presbyopic, that would mean wearing spectacles with their scleral lenses for near visual tasks. However, there are presbyopic scleral lens patients who can obtain functional distance and near vision with multifocal scleral lenses.
Many of the commercially available scleral lenses have the option for adding multifocal optics. However, scleral lenses don’t translate and require a multifocal design to utilize simultaneous vision. Most of the designs offered are center near, although center distance is available. An aspheric transition zone between near and distance can extend a patient’s intermediate range.
Candidates
The simultaneous nature of multifocal scleral lens optics requires neural adaptation for patients to subjectively succeed with multifocal optics. Even under perfect circumstances, some patients aren’t able to accept the degradation in vision that is inherent to simultaneous optics as compared to single-vision distance.
Patients who have best-corrected vision with standard scleral lenses of 20/30 or worse—which can be the case for patients who have extreme front- and back-surface corneal irregularity—will be poor candidates for multifocal scleral lenses because of further compromises in distance acuity. For these patients, prescribing monovision or glasses to wear over their contact lenses may be a better option.
Post-myopic refractive surgery patients who have failed with soft lenses secondary to dryness or fit issues can be ideal candidates for multifocal scleral lenses (Figure 1).
Figure 1. A multifocal scleral lens on a patient post-myopic
LASIK who failed in soft contact lenses.
Fitting
To order multifocal scleral lenses, measure the patient’s photopic pupil size and add power in addition to determining all other standard scleral lens parameters that will be used for a successful fit. Fit the patient with a relatively smaller scleral lens diameter (16mm or less), because a smaller lens will generally be more likely to center, which is critical for multifocal scleral lens success.
Taking topography over the fitted lens can help you determine relative scleral lens centration. Demonstrate possible sphere power changes with spectacle trial lenses over a dispensed multifocal lens to enhance distance and near power. Adding mild amounts of additional plus power to the nondominant eye can help a patient who is struggling with near vision.
In Summary
Multifocal optics will be increasingly used to improve the functionality of scleral lenses, especially for dry eye and post-refractive surgery patients. Additionally, future innovations will improve manufacturers’ ability to center multifocal optics over the visual axis despite a scleral lens that decenters on the eye. CLS
Dr. DeNaeyer is the clinical director for Arena Eye Surgeons in Columbus, Ohio. He is a shareholder of Precision Ocular Metrology LLC, has proprietary interest in Visionary Optics’ Europa and Elara Scleral Lenses, and is a consultant to Visionary Optics and Alcon. You can contact him at gdenaeyer@arenaeyesurgeons.com.