BACKGROUND: Severe keratoconic patients who exhibit large amounts of irregular astigmatism and a prominent inferior oval apical protrusion are very challenging contact lens fits. Traditional rigid gas permeable lens designs and specialty lens options such as Soft-Perm and piggyback designs may not provide satisfactory fitting relationships. A good alternative for these irregular corneas is the Epicon, a corneo-scleral rigid lens.
CASE REPORT(S). A 42-year old Albanian male with advanced bilateral keratoconus was referred for a contact lens consultation. Previous contact lens fittings proved to be unsuccessful. His spectacle Rx was: OD: +0.50- 2.25 x 081 BCVA 20/40; OS: +0.50- 1.50 x 085 BCVA 20/25. Topographical analysis revealed an irregular inferior oval cone formation, OD>OS. Simulated K values were OD: 52.45/48.28@060; OS: 46.15/44.47@080. A successful fitting relationship with excellent visual acuity was achieved for both eyes with Epicon lenses. The final lens parameters were: 6.80/-7.00/13.5 with a median peripheral curve system for both eyes. A central lens position was achieved with mild central pooling, inferior mid-peripheral alignment and moderate peripheral edge clearance OU. The large diameter lens not only protected the area of compromised inferior ectasia, but also reduced patient symptoms of diplopia and glare that were experienced with other lens designs. Furthermore, the Epicon lens allows a greater amount of oxygen to be transmitted to the diseased cornea than other specialty lens options that may compromise corneal physiology by inducing a hypoxic environment.
CONCLUSIONS. Epicon’s corneo-scleral lens design is a promising alternative to currently available specialty contact lens options in the fitting of advanced keratoconus.