Article

HYBRID HOW-TO

WHEN 20/20 IS NOT GOOD ENOUGH

One of the realities of working within an optometric academic institution is that our optometric students can become some of the pickiest patients to sit in the exam chair. Their high demands are comparable to non-optometry patients who are extremely sensitive to the slightest depreciation in visual quality.

For those who present with at least 0.75D of refractive astigmatism, we often elect to fit a soft toric disposable contact lens. What happens when some of these patients complain of fluctuating vision, intermittent blur, or just “OK” vision? Wouldn’t you want to provide those patients with an option that could take their shaky 20/20- to a solid 20/20?

Case in Point

A third-year optometry student, who had an unremarkable health history, had a spectacle prescription of OD –5.25 –1.25 x 180 and OS –5.00 –2.00 x 177. Baseline topography OD (Figure 1) showed approximately 1.50D of nearly limbus-to-limbus corneal astigmatism. He had tried daily disposables but was currently wearing a monthly lens. He reported intermittent fluctuating vision throughout the day, yet records showed near-perfect Snellen acuity endpoints with all lenses trialed. He tested hybrid lenses during a workshop and had interest in switching into this modality for full-time wear.

Figure 1. Baseline topography. Corneal Astigmatism: 1.47D

Topographies overtop new trials of his previously prescribed daily disposable hydrogel lens (Figure 2) and monthly replacement lens (Figure 3) showed 0.76D and 1.04D of residual astigmatism, respectively. In contrast, topography overtop the GP center of an ordered hybrid lens (Figure 4), fit according to manufacturer recommendations, revealed 0.39D of residual cylinder. Each topography measurement was taken a minimum of two hours post-lens application on separate days.

Figure 2. Daily disposable hydrogel. Residual Astigmatism: 0.76D

Figure 3. Monthly replacement lens. Residual Astigmatism: 1.04D

Figure 4. Hybrid lens. Residual Astigmatism: 0.39D

This pictorial comparison shows the least amount of residual astigmatism with the hybrid lens on eye. Whether related or not, the quality of vision while wearing the hybrid lens was superior, as reported by the patient and the recorded 20/20+ Snellen acuity OD that was achieved. This patient continues to wear his hybrid lenses. CLS