contact lens case reports
Improving Comfort and Vision for a Keratoconus Patient
BY PATRICK J. CAROLINE, FAAO, & MARK P. ANDRÉ, FAAO
In previous columns we've discussed the use of a number of custom spherical, aspheric and toric soft contact lens designs for keratoconus. Clinical experience has taught us that despite the counterintuitive nature of using these lenses on an irregular cornea, the visual outcomes can often be quite surprising. Currently, a number of laboratories in the United States manufacture or distribute soft contact lenses for keratoconus including Advanced Vision Technologies, Inc., Continental Soft Lens, X-Cel Contacts, Inc., Gelflex USA, Marietta Vision, Medlens Innovations, Inc., Ocu-Ease Optical Products, Inc., Strategic Lens Innovations Corp. (SLIC),United Contact Lens, Inc. and SpecialEyes, LLC.
A Case of GP Lens Intolerance
Our patient was a 39-year-old male who was first diagnosed with keratoconus at age 28. In this form of late-onset keratoconus, both eyes are frequently affected to a similar degree, often with little or no asymmetry to the corneal topographies or refractive errors.
The patient reported a history of limited success with GP lenses due to excessive inferior lens decentration that resulted in suboptimal vision, comfort and wearing time. Approximately five years ago he was fitted with custom toric soft lenses in an attempt to address these issues.
At his initial presentation to our clinic, the patient's chief complaint was a persistent shadowing of his vision with significant symptoms of nighttime glare and halos. His distance VAs were OD 20/40 and OS 20/50.
Figure 1. Corneal topographies and SpecialEyes Custom Toric Soft Lenses.
We again attempted to refit the patient into GP lenses. Despite a rather optimum fit with aspheric, apical clearance lenses, the patient was unable to achieve adequate comfort and wearing time.
Customizing a Soft Lens
We abandoned GP lenses and refit the patient into custom soft toric contact lenses from SpecialEyes, LLC in Brandenton, Florida. The initial lenses were designed empirically based on the patient's manifest refraction, horizontal visible iris diameter and keratometry readings. The initial lenses ordered were OD 8.1mm base curve, 14.7mm diameter, –2.75 –1.25 ×090 and OS 8.2mm base curve, 14.7mm diameter, –3.25 –1.75 ×120. Both lenses incorporated an 8.5mm optical zone.
At the dispensing and one-week follow-up visits, the patient reported adequate vision; however, he was still experiencing constant shadows and halos at night. The patient's pupils were 5.5mm in room illumination and 7.5mm in photopic illumination, so we reordered new lenses from SpecialEyes with 10.0mm optical zones (Figure 1). Two weeks after dispensing, the patient returned with clear 20/25 vision and a dramatic improvement in his nighttime symptoms.
This case illustrates how effective soft lenses can be in managing keratoconus and how a simple change in optical zone diameter can dramatically impact a patient's visual outcome. CLS
Patrick Caroline is an associate professor of optometry at Pacific University. He is also a consultant to Paragon Vision Sciences. Mark André is an associate professor of optometry at Pacific University. He is also a consultant for CooperVision and SynergEyes, Inc.