Inadequate GP Lens Fitting in Keratoconus
This 30-year-old female patient has binocular, stage 2 keratoconus (Figure 2). There is a single intracorneal ring segment in her left eye. She was first seen and fit with specialty GPs at our clinic in 2014. The fit was successful, and she wore the lenses for four consecutive years without any problems. In 2018, she went to another practice for a GP fitting. In August 2019, she came back to our clinic complaining of discomfort, especially in her left eye.
Primary examination with fluorescein showed a right lens with no central touch but insufficient peripheral curves (Figure 1 left). The lens was also adhered, and after removing it, we were able to see the mark of the lens on the cornea. Her left eye demonstrated corneal keratitis possibly leading to corneal erosion (Figure 1 right).1
Management of the Case
She was instructed to suspend lens wear on both eyes—for three days OD and for five days OS—and then to return for re-evaluation and specialty GP fitting.
The patient returned one week later. The left eye had completely recovered, and we fit new GP lenses OD and OS. The objective for the right lens was better corneal alignment and a peripheral, aspheric periphery to allow adequate tear pumping and avoid the lens adhesion that she experienced with the previous lens. For the left lens, we needed to vault the apex of the cone and also avoid touch at the elevation created by the ring segment at the inferior paracentral cornea.2 Figure 3 shows the new fit with an excellent fluorescein pattern, optimal tear exchange, good comfort, and VA of 20/20+ OD and OS.
The presence of the intracorneal segment in her left eye induced an anterior elevation at the inferior, paracentral cornea. In this case, it was necessary to use a specialty GP keratoconus lens designed for intracorneal ring fitting. This lens is a little bit larger compared to the OD lens and also has a larger optical zone, resulting in a higher sagittal height if compared with same parameters in the normal keratoconus design. Figure 4 shows the side view of the OS fit.
The primary objectives in our contact lens fitting practice are comfort, excellent anterior eye physiological health, and the best possible visual acuity. When you focus on the details and strive to ultra-customize the fit, it will usually lead to success, particularly on the more complex cases in which the correct modifications in the design are needed.
- White P. Contact Lens Complications - Part II. Contact Lens Spectrum. 2000 Feb;14:33-40.
- Bastos L. Fitting Keratoconus After Intracorneal Ring Implants. Contact Lens Spectrum. 2011 Nov;26:40-42.