Using a Scleral Lens To Control Myopia
BY CARY M. HERZBERG, OD, FIOS
In the mid '90s, I made a decision in my practice that had far-reaching effects. I had grown tired of watching my patients require stronger prescriptions every year. I was especially concerned with my young patients who developed advanced cases of myopia without any family history. Some of my young pa
about my young patients who developed advanced cases of myopia without any family history. Some young patients with myopic parents had already exceeded their parents' formidable prescriptions at a very young age.
A New Design
The MacroLens (C & H Contact Lens, Inc.) came into my practice in 1997. For many years I had searched for a rigid lens that I could successfully fit to soft lens wearers and active patients of all ages. Robert Cotie developed a rigid scleral lens, the MacroLens, featuring 14.0mm to 15.0mm diameter that was comfortable to wear and delivered all the benefits of rigid lenses.
Because MacroLens has a large diameter, it more effectively treats the cornea than smaller diameter lenses. Its first applications included fitting RK patients who had poor surgical outcomes. Such patients have very irregular corneas that are challenging to fit. This phase of MacroLens fitting showed that this lens is versatile.
At first only the non-adjustable MacroLens "D" was available. This lens proved comfortable but fit only 50 percent of patients successfully. Practitioner requests for a more "hands on" lens led to the adjustable "A" design, with almost 80 percent fitting success.
MacroLens entered the new millennium with "H" and "CH" designs that featured improved tear pooling capabilities and versatility, bringing fitting success to over 90 percent.
I recently completed a retrospective study of MacroLens patients in my practice. I randomly selected 37 patients who had worn the MacroLens for at least one year. There were 16 male patients and 21 female patients. Most (62 percent) were in the group aged 10 to 20, which tends to exhibit the greatest degree of myopic change. There were nine patients aged 21 to 30, four patients aged 31 to 40 and one patient between 41 and 50 years old. I evaluated each patient with best refraction and automated keratometry.
Myopia decreased in both eyes for the majority of study patients (70 percent). All eyes exhibited an average corneal flattening of 0.15D. Refractive change was larger, resulting in 0.238D less myopia on average. MacroLens also reduced the eccentricity and overall astigmatism of study corneas (Figures 1 and 2).
MacroLens offers clinicians a safe, non-invasive method of containing myopia. I have fit patients as young as five years old with this lens. It will be interesting to see long-term how their vision responds.
Dr. Herzberg practices in Aurora. IL, and is a technical consultant to the contact lens industry.