“If it ain’t broke, don’t fix it” isn’t a mantra that I particularly agree with, especially when it comes to refitting established scleral lens (SL) wearers. Constant advancements in SL technologies empower practitioners to provide clear vision and better comfort for many patients who were left with “this is all we can do” fits prior. However, be prepared to face obstacles that may have been masked by lenses of the past.

Adjusting for Scleral Toricity

A 23-year-old male who has keratoconus presented to our clinic wearing spherical-haptic SLs. His chief complaint was ocular irritation after several hours of wearing his left SL. Upon presentation, the right SL fit well and required only a small power change. The left SL exhibited moderate blanching at the nasal and temporal meridians. This classic pattern, indicative of a with-the-rule (WTR) sclera, shows that scleral shape variations can occur even in the same patient. Prominent conjunctival staining and nasal pinguecula irritation at the areas of tightness were also observed (Figure 1).

We performed an over-refraction, then incorporated a toric peripheral haptic and nasal vault to improve vision, mitigate blanching, and decrease pinguecula interaction. The patient reported improved comfort and minimal lens sensation with the new trial lens, which appeared to align well in all meridians and vaulted the pinguecula nicely (Figure 2). Unfortunately, he reported blurry vision, and an over-refraction revealed a moderate amount of uncorrected WTR astigmatism that was not present at past visits.

Troubleshooting the Vision

Why did we suddenly have this astigmatism? Autorefraction (AR) over contact lenses has quickly become part of my lens fitting process, as it requires minimal time and can provide a starting point for over-refraction while highlighting the presence of lens flexure. AR revealed minimal flexure over the new trial lens. With the patient’s habitual SL, however, there was 1.37DC of flexure. The visual clarity experienced through the habitual SL was due to a combination of beneficial WTR lens flexure and a low-powered spherical equivalent:

Negating the lens flexure with the improved haptic alignment allowed the patient’s intrinsic against-the-rule lenticular astigmatism to manifest.

Fortunately, SL advancements make it possible to order a reproducible lens with front-surface and back-surface toricity along with a peripheral vault. The second trial lens for the left eye (Table 1) fit nicely and provided acceptable vision. CLS