- Email: [email protected]
Modern Designs of Contact Lenses as a Way to Improve Vision of Keratoconus and Pellucid Marginal Degeneration (PMD) Patients
Poster Presentations Poster 20 Modern Designs of Contact Lenses as a Way to Improve Vision of Keratoconus and Pellucid Marginal Degeneration (PMD) Patients Langis Michaud, O.D., M.Sc., E´cole D’Optome´trie de l’Universite´ de Montre´al, 3744 Jean-Brillant #190-70, Montre´al, Que´bec H3T1P1 Introduction: Keratoconus and Pellucid Marginal Degeneration (PMD) are corneal ectasia known to produce irregular astigmatism that severely affects visual acuity of patients. The clinical management of keratoconus varies depending on the severity of the condition and can range from nonsurgical options such as glasses and contact lenses to surgical interventions including cross-linking, intrastromal inlays, and penetrating keratoplasty. The initial treatment consists of optical correction. However, when the disease progresses to advanced stages, surgical procedures are necessary, such as wedge resection, lamellar crescentic resection, penetrating keratoplasty, lamellar keratoplasty, epikeratoplasty, and, recently, intracorneal inlays. Methods: To evaluate which is the preferred mode of correction and its outcome, an analysis of the 50 last keratoconus/PMD patients seen at/referred to the Clinique Universitaire de la Vision for contact lens fitting or for their regular follow-up was made. The following elements were collected for analysis: diagnosis/type of keratoconus, visual acuity (uncorrected, with glasses, with contact lenses), and the mode of correction (type of contact lenses). Results: Eighty-five eyes had keratoconus diagnosed based on topographic maps (13 Nipple cone [15.3%], 59 oval shape cone [69.4%], 10 globus cone [11.7%], and 3 fruste form of keratoconus [3.5%]); 9 eyes presented with a mapping suggesting PMD; 6 eyes presented with another corneal entity (irregular astigmatism [1], corneal warpage secondary to contact lens wear [4], and post-LASIK ectasia [1]). These 6 last patients were not selected for further analysis. Uncorrected visual acuity ranged from 20/400 to 20/ 50 and had improved to 20/30 to 20/20 depending on the mode of correction. For nipple cone and PMD, aspheric GP lenses were preferred, whereas piggyback was the correction of choice for oval and global types of keratoconus. Soft high Dk lenses were used to correct frustre form of keratoconus. Semi-scleral lenses were also considered when GP failed to improve the vision or were not tolerated based on the comfort. Conclusion: Contact lenses are a viable option to restore visual acuity for keratoconic and PMD patients. Modern designs of contact lenses help provide the best visual acuity while maintaining good ocular health over time. Most popular designs include: GP lenses (keratoconus lenses, used alone or in a piggyback system when coupled with silicone hydrogel high Dk material) providing increased comfort and a good visual acuity; hybrid lenses that ease the wear but have limited use for some patients
295 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 become the next standard of care in irregular cornea contact lens fitting.
Low Vision Poster 21 See One, Do One, Teach One: The Vision Enhancement System (VESÒ Sport) Marissa N. Adamson, O.D., and Joni Scott-Weideman, O.D., CPT, USAFR, Tallahassee Veterans Affairs Outpatient Clinic, 1607 St. James Court, Tallahassee, Florida 32308 Background: Stargardt’s, an autosomal recessive disease, is one of the most common juvenile forms of macular degeneration. Diagnosis is typically made before 20 years of age and is linked to a mutation of the ABCR gene. Vision loss is gradual and typically ranges between 20/200-20/400, with central vision being the most affected. Because of the early onset of vision loss, low vision devices are the key component in allowing patients to maximize visual function throughout their life. Case Summary: A 47-year-old-white man with Stargardt’s presented to the VA TOPC low vision clinic with a desire to return to school to pursue a master’s degree in social work. He had previously been prescribed handheld magnifiers and a CCTV. Presenting central visual acuities at distance 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 being able to see the board, view presentations, and take notes in the classroom. To meet these goals, we searched for a multifocal, portable optical device. We fit him with a 4X VESÒ Sport bioptic telescope, superiorly mounted over the right eye with his current prescription in the carrier lenses. The 4X VESÒ Sport, made by Ocutech, has an adjustable focus that can be changed quickly and efficiently to meet his goals in a dynamic classroom environment. Utilizing eccentric viewing, the patient was able to achieve 20/40 at distance and 0.8 M at 20 cm. At follow-up visit, the patient reported that he was successfully using 4X VESÒ Sport in the classroom. Conclusion: Low vision patients may need multiple devices depending on the visual task they wish to perform. This case is a good example of optimizing the patient’s visual function with a user-friendly bioptic. As optometric practitioners, we should be familiar with low vision optical devices available to our patients, either for successful prescribing or for referral to optometrists specializing in low vision care.
295 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 become the next standard of care in irregular cornea contact lens fitting.
Low Vision Poster 21 See One, Do One, Teach One: The Vision Enhancement System (VESÒ Sport) Marissa N. Adamson, O.D., and Joni Scott-Weideman, O.D., CPT, USAFR, Tallahassee Veterans Affairs Outpatient Clinic, 1607 St. James Court, Tallahassee, Florida 32308 Background: Stargardt’s, an autosomal recessive disease, is one of the most common juvenile forms of macular degeneration. Diagnosis is typically made before 20 years of age and is linked to a mutation of the ABCR gene. Vision loss is gradual and typically ranges between 20/200-20/400, with central vision being the most affected. Because of the early onset of vision loss, low vision devices are the key component in allowing patients to maximize visual function throughout their life. Case Summary: A 47-year-old-white man with Stargardt’s presented to the VA TOPC low vision clinic with a desire to return to school to pursue a master’s degree in social work. He had previously been prescribed handheld magnifiers and a CCTV. Presenting central visual acuities at distance 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 being able to see the board, view presentations, and take notes in the classroom. To meet these goals, we searched for a multifocal, portable optical device. We fit him with a 4X VESÒ Sport bioptic telescope, superiorly mounted over the right eye with his current prescription in the carrier lenses. The 4X VESÒ Sport, made by Ocutech, has an adjustable focus that can be changed quickly and efficiently to meet his goals in a dynamic classroom environment. Utilizing eccentric viewing, the patient was able to achieve 20/40 at distance and 0.8 M at 20 cm. At follow-up visit, the patient reported that he was successfully using 4X VESÒ Sport in the classroom. Conclusion: Low vision patients may need multiple devices depending on the visual task they wish to perform. This case is a good example of optimizing the patient’s visual function with a user-friendly bioptic. As optometric practitioners, we should be familiar with low vision optical devices available to our patients, either for successful prescribing or for referral to optometrists specializing in low vision care.