Oct. 25, 2024
Since 2014, the Scleral Lenses in Current Ophthalmic Practice: An Evaluation (SCOPE) study group has worked to provide a better understanding of the role and performance of scleral lenses in clinical practice. Scleral lenses were first described in the late 1800s, but did not become practical for clinical use until the late 1990s. Since 2010, scleral lenses have become increasingly prescribed for a broad range of applications in corneal irregularity, ocular surface disease and even for common uncomplicated refractive error.
Scleral lenses are more comfortable than corneal rigid lenses, sometimes called hard lenses. Scleral lenses also provide comparable vision to that which can be achieved through other rigid lens modalities. "With the benefit of increased comfort, many patients who would have otherwise required corneal transplants can delay or even avoid surgery by wearing scleral lenses," says study group founder Muriel M. Schornack, O.D., an optometrist at Mayo Clinic's campus in Rochester, Minnesota. "Widespread scleral lens prescription is a relatively recent phenomenon. Studies which investigate the effects of these devices on ocular anatomy and physiology are needed."
"Our experience is that scleral lenses carry a more rigorous burden of care than other contact lens modalities," adds Cherie B. Nau, O.D., also an optometrist at Mayo Clinic in Minnesota. "The incidence of complications of scleral lens wear has yet to be defined. The most serious complication of any contact lens wear is microbial keratitis — a potentially blinding complication. Several individual case reports of microbial keratitis associated with scleral lens wear have been reported. Survey-based estimates of the period prevalence of microbial keratitis associated with scleral lens wear suggest that this condition may occur in approximately 45 of 10,000 patients per year."
To address these concerns, the SCOPE study group conducts research that helps document the shift toward expanded use of scleral lenses and the effects and implications of that expansion.
The SCOPE study group conducted these four recent studies.
How to quantify midday fogging
The article "Changes in optical density of post-lens fluid reservoir during 2 hours of scleral lens wear," addresses one of the issues associated with scleral lens wear: midday fogging. This is a phenomenon that occurs when debris becomes entrapped in the fluid reservoir that is maintained between the lens and the cornea.
This study evaluated a method to quantify increases in turbidity of the post-lens fluid reservoir by assessing changes in optical density of the fluid over time and compared these changes during two hours of scleral lens wear using three different lens designs. Outcomes indicated:
- Optical density of the post-lens fluid reservoir can be quantified during scleral lens wear.
- During two hours of wear, fluid reservoir optical density doubled with all lens designs evaluated.
Assessing current scleral lens use for guideline development
The article "Scleral lenses in the management of corneal irregularity and ocular surface disease" concluded:
- A reasonable degree of consensus exists regarding some aspects of scleral lens prescription and management (average lens diameter, daily wearing time and use of nonpreserved products for lens application).
- Further study is needed to develop evidence-based guidelines for scleral lens prescription and management.
Use of scleral lenses for corneal irregularity and ocular surface disease
This study describes current practice patterns regarding the use of scleral lens therapy in the management of corneal irregularity and ocular surface disease among eye care clinicians who fit scleral lenses. Outcomes include:
- Scleral lenses rank second only to corneal rigid, gas permeable lenses for management of corneal irregularity.
- Scleral lenses are generally considered after other medical intervention and before surgery for the management of ocular surface disease.
Who prescribes scleral lenses and for what conditions?
The article "Demographic characteristics and prescribing patterns of scleral lens fitters: The SCOPE study" reports characteristics and indications for scleral lens prescription as assessed by a worldwide online survey. Results indicate:
- Eye care professionals of all ages are fitting scleral lenses.
- The number of individuals who fit this lens modality has increased during the past decade.
- Health care professionals in a wide range of practice settings are fitting scleral lenses.
- Most scleral lenses are prescribed for corneal irregularity.
Future research
The SCOPE study group has two studies before an Institutional Review Board: One addresses patient concerns with scleral lenses, and the second compares patient experience of scleral lenses with different peripheral designs.
For more information
Contact Dr. Nau at nau.cherie@mayo.edu or Dr. Schornack at schornack.muriel@mayo.edu.
Schornack MM, et al. Changes in optical density of post-lens fluid reservoir during 2 hours of scleral lens wear. Eye & Contact Lens. 2018;44:S228.
Shorter E, et al. Scleral lenses in the management of corneal irregularity and ocular surface disease. Eye & Contact Lens. 2018;44:372.
Nau CB, et al. Demographic characteristics and prescribing patterns of scleral lens fitters: The SCOPE study. Eye & Contact Lens. 2018;44:S265.
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