Poster Presentations 295

Poster 20

Modern Designs of Contact Lenses as a Way to ImproveVision of Keratoconus and Pellucid MarginalDegeneration (PMD) Patients

Langis Michaud, O.D., M.Sc., Ecole D’Optometrie del’Universite de Montreal, 3744 Jean-Brillant #190-70,Montreal, Quebec H3T1P1

Introduction: Keratoconus and Pellucid Marginal Degen-eration (PMD) are corneal ectasia known to produce irreg-ular astigmatism that severely affects visual acuity ofpatients. The clinical management of keratoconus variesdepending on the severity of the condition and can rangefrom nonsurgical options such as glasses and contactlenses to surgical interventions including cross-linking, in-trastromal inlays, and penetrating keratoplasty. The initialtreatment consists of optical correction. However, whenthe disease progresses to advanced stages, surgical proce-dures are necessary, such as wedge resection, lamellarcrescentic resection, penetrating keratoplasty, lamellar ker-atoplasty, epikeratoplasty, and, recently, intracornealinlays.Methods: To evaluate which is the preferred mode of cor-rection and its outcome, an analysis of the 50 last kerato-conus/PMD patients seen at/referred to the CliniqueUniversitaire de la Vision for contact lens fitting or fortheir regular follow-up was made. The following elementswere collected for analysis: diagnosis/type of keratoconus,visual acuity (uncorrected, with glasses, with contactlenses), and the mode of correction (type of contactlenses).Results: Eighty-five eyes had keratoconus diagnosed basedon topographic maps (13 Nipple cone [15.3%], 59 ovalshape cone [69.4%], 10 globus cone [11.7%], and 3 frusteform of keratoconus [3.5%]); 9 eyes presented with a map-ping suggesting PMD; 6 eyes presented with another cor-neal entity (irregular astigmatism [1], corneal warpagesecondary to contact lens wear [4], and post-LASIK ectasia[1]). These 6 last patients were not selected for further anal-ysis. Uncorrected visual acuity ranged from 20/400 to 20/50 and had improved to 20/30 to 20/20 depending on themode of correction. For nipple cone and PMD, asphericGP lenses were preferred, whereas piggyback was the cor-rection of choice for oval and global types of keratoconus.Soft high Dk lenses were used to correct frustre form ofkeratoconus. Semi-scleral lenses were also consideredwhen GP failed to improve the vision or were not toleratedbased on the comfort.Conclusion: Contact lenses are a viable option to restorevisual acuity for keratoconic and PMD patients. Moderndesigns of contact lenses help provide the best visual acu-ity while maintaining good ocular health over time. Mostpopular designs include: GP lenses (keratoconus lenses,used alone or in a piggyback system when coupled withsilicone hydrogel high Dk material) providing increasedcomfort and a good visual acuity; hybrid lenses thatease the wear but have limited use for some patients

because of the low oxygen permeability of the soft skirt,and semi-scleral lenses that provide stability and comfort.The authors expect the latter mode of correction to be-come the next standard of care in irregular cornea contactlens fitting.

Low Vision

Poster 21

See One, Do One, Teach One: The Vision EnhancementSystem (VES� Sport)

Marissa N. Adamson, O.D., and Joni Scott-Weideman,O.D., CPT, USAFR, Tallahassee Veterans AffairsOutpatient Clinic, 1607 St. James Court, Tallahassee,Florida 32308

Background: Stargardt’s, an autosomal recessive disease, isone of the most common juvenile forms of macular degen-eration. Diagnosis is typically made before 20 years of ageand is linked to a mutation of the ABCR gene. Vision lossis gradual and typically ranges between 20/200-20/400,with central vision being the most affected. Because ofthe early onset of vision loss, low vision devices are thekey component in allowing patients to maximize visualfunction throughout their life.Case Summary: A 47-year-old-white man with Stargardt’spresented to the VA TOPC low vision clinic with a desireto return to school to pursue a master’s degree in socialwork. He had previously been prescribed handheld magni-fiers and a CCTV. Presenting central visual acuities at dis-tance were 20/400 in each eye with 22.7520.75X169,22.7520.75X002, respectively. Near acuities were 8 M(20/400) without correction. His specific goals included be-ing able to see the board, view presentations, and take notesin the classroom. To meet these goals, we searched for amultifocal, portable optical device. We fit him with a 4XVES� Sport bioptic telescope, superiorly mounted overthe right eye with his current prescription in the carrierlenses. The 4X VES� Sport, made by Ocutech, has an ad-justable focus that can be changed quickly and efficiently tomeet his goals in a dynamic classroom environment. Utiliz-ing eccentric viewing, the patient was able to achieve 20/40at distance and 0.8 M at 20 cm. At follow-up visit, the pa-tient reported that he was successfully using 4X VES�Sport in the classroom.Conclusion: Low vision patients may need multiple devicesdepending on the visual task they wish to perform. Thiscase is a good example of optimizing the patient’s visualfunction with a user-friendly bioptic. As optometric practi-tioners, we should be familiar with low vision optical de-vices available to our patients, either for successfulprescribing or for referral to optometrists specializing inlow vision care.