Sept. 21, 2018
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 have traditionally been prescribed to address eye conditions that may not respond to other forms of treatment. Since 2010, however, 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.
"Because scleral lenses are more comfortable than corneal gas permeable (sometimes referred to as "hard") lenses and provide vision that is just as clear as corneal rigid, gas permeable lenses, they're now being prescribed for a broad range of applications," says study group founder Muriel M. Schornack, O.D., an optometrist at Mayo Clinic's campus in Rochester, Minnesota. "We need a far better understanding of the issues, implications and long-term effects of this shift."
"Our experience is that scleral lenses also carry a rigorous burden of care and long-term effects," adds Cherie B. Nau, O.D., also an optometrist at Mayo Clinic, Rochester, Minnesota. "Scleral lenses can compress drainage channels in the eye and may be associated with conjunctival damage. The bigger concern is microbial keratitis — a potentially blinding complication. We suspect scleral lens wear may be associated with cases of microbial keratitis that have not yet been reported in the literature."
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. Four recent studies include:
How to quantify midday fogging
Schornack MM, et al. Changes in optical density of post-lens fluid reservoir during 2 hours of scleral lens wear. Eye & Contact Lens. In press.
One of the issues associated with scleral lens wear is "midday fogging," 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
Harthan J, et al. Scleral lens prescription and management practices: The SCOPE study. Eye & Contact Lens. 2018;44:S228.
This study assessed current scleral lens prescription and management practices via an international online survey of eye care providers. Researchers 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
Shorter E, et al. Scleral lenses in the management of corneal irregularity and ocular surface disease. Eye & Contact Lens. In press.
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 providers 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?
Nau CB, et al. Demographic characteristics and prescribing patterns of scleral lens fitters: The SCOPE study. Eye & Contact Lens. 2018;44:S265.
This study reports demographic characteristics of scleral lens providers and indications for scleral lens prescription as assessed by a worldwide online survey. Results indicate:
- Eye care providers of all ages are fitting scleral lenses.
- The number of individuals who fit this lens modality has increased during the past decade.
- Providers 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 patients with ocular hypertension, 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.