Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Visual impairment wikipedia , lookup
Blast-related ocular trauma wikipedia , lookup
Vision therapy wikipedia , lookup
Visual impairment due to intracranial pressure wikipedia , lookup
Corneal transplantation wikipedia , lookup
Corrective lens wikipedia , lookup
Keratoconus wikipedia , lookup
When ‘eye’ move, you move: Scleral lenses in a case of oculocutaneous albinism-induced nystagmus By: Anita Gulmiri, OD I. Case History: ● 15 year-old white male with congenital oculocutaneous albinism complains of blurry vision with current spectacles, nystagmus, and a secondary complaint that eyes do not stay open / squinting with current spectacles. ● Date of initial exam: 07/23/15, date of CL fitting: 08/13/15, date of lens pick up and eval: 08/27/15 ● Medical History: oculocutaneous albinism, no medications and no allergies ● Ocular History: high hyperopia, high astigmatism, nystagmus, accommodative esotropia, and amblyopia, photosensitivity when outdoors. Previous history of failure with soft toric contact lenses, and small diameter RGP lenses. II. Pertinent Findings ● Entering visual acuity with current spectacles was 20/400 OD and OS with a 20Δ intermittent and variable right accommodative esotropia. Corneal topography shows simK: OD :42.60/46.11@165 and OS: 39.94/43.65@086, however imaging was unstable due to patient’s nystagmus. Final Spec RX was OD: +4.50-6.00x020 (VA 20/400) and OS: +4.50-6.00x165 (VA 20/400) Slit lamp examination reveals complete poliosis of eyebrows and eyelashes OU, clear cornea OU, iris transillumination defects 360 OU, and foveal hypoplasia OU. III. Diagnosis: Oculocutaneous albinism causing nystagmus, high astigmatism and high hyperopia, strabismus, amblyopia and photosensitivity (most bothersome when outdoors). Differential Diagnosis: Various contact lens options were considered including higher modulus soft toric contact lenses which could provide better stability, bitoric small diameter gas permeable lenses, custom-tinted soft toric contact lenses for photosensitivity, and possibly surgical options (limbal relaxing incisions to reduce astigmatism). Ultimately, scleral lenses were chosen to minimize invasiveness, protect ocular surface, provide stability and maintain comfort. IV: Diagnosis and Discussion ● Oculocutaneous albinism is an inherited condition that affects the pigmentation of the eyes, skin, and hair (5). It is a rare condition affecting only 1 in 17,000 patients (1,5). Patients with this condition have reduced distance vision, rapid, involuntary eye movements (nystagmus) and increased sensitivity to light due to reduced pigmentation of the iris and macula. Patients also usually have highly visible choroidal vasculature due to retinal hypopigmentation (3). Best-corrected visual acuity may range from 20/40 to 20/400 depending on the severity of condition. Some patients may also have strabismus, secondary amblyopia, and therefore reduced stereopsis (2). Nystagmus begins at age 23 months and usually remains constant and stable throughout life. External signs and slit lamp findings include depigmentation of eyebrows, eyelashes, iris transillumination defects, and hypoplastic foveae. ● A quality of life survey for patients with albinism revealed that a 100% of patients with albinism experience blurred distance vision with best correct spectacles, 60% have difficulty watching TV and 50% have difficulty crossing the road alone. Patients with albinism suffer overall from a lower quality of life due to reduced vision at distance and glare (7). Contact lenses may serve to improve quality of life for patients with nystagmus. (2) ● Due to the patient’s high refractive error and nystagmus, vision is not optimal with spectacles. Previously unsuccessful with soft toric contact lenses (due to lack of stable vision with variable lens rotation) and intolerant to small diameter corneal GP lenses (due to lack of comfort and decentering lens), per patient’s mother. Large diameter RGP lens were chosen to provide comfortable, stable, and optimal vision. V: Treatment, management ● New CL fit with Valley Contax (Springfield,OR,USA), Custom Stable Elite scleral lenses ○ OD BC 8.23/+4.00/sag 3.66 and dia 14.8, BOSTON XO, toric PCs ○ OS BC 8.23/+3.25/sag 3.66 and dia 14.8 BOSTON XO, toric PCs ○ Custom Stable Elite chosen vs Custom Stable to provide scleral alignment due to high corneal cyl contributing to toric scleral anatomy. ● Vision improves from 20/400 (spectacles) to 20/100+ OD/OS with scleral lenses with potential of visual acuity improving to 20/80 with an over-refraction. The benefits of contact lenses vs. spectacles can be explained by the idea that nystagmus decreases due to increased vergence and accommodative effort with contact lenses. Additionally, lenses improve vision in patients with nystagmus by maintaining alignment with optical axis, since lens moves with eye movements (4). ● In a report by Biousse et al, it was concluded that all patients preferred contact lenses over spectacles with an improvement in contrast sensitivity with contact lenses than with spectacles alone (2). ● Although small diameter gas permeable lenses would have provided similar improvement in visual acuity, scleral lenses have the added benefit of comfort. One study Lahnstein et al did argue that small diameter GP lenses may dampen nystagmus due to tactile feedback from GP lens edge awareness (4). ● Children may not be ideal for scleral lenses due to small aperture size and possible difficulty with insertion, removal and lens care. However, in this case, the benefits of increased comfort and vision outweigh the potential hurdles. ● While objectively, there is a modest improvement of visual acuity, there is a marked improvement in the quality of vision experienced by the patient. After being fit with scleral lenses, patient reports this is the best his vision has ever been, he is able to discern details on buildings and see features on mother’s face for the first time. He also feels his eyes do not move as much because he’s able to focus better when lenses are on vs. spectacles. ● Mother notices patient is able to keep his eyes open when scleral lenses on vs. when patient is wearing spectacles. While this is an unusual outcome, the plan moving forward at the next follow up visit is to measure aperture size with specs vs. with scleral contact lenses to measure objective difference. If significant change in aperture size, explore possible reasons for the difference. ● Other treatment and follow up plans include sunglasses to control photosensitivity when outdoors, improvements in overall fit of scleral lenses to possibly further improve visual acuity, re-measure visual acuity with low vision charts and/or contrast sensitivity charts for more precise visual acuities. VI: Conclusion ● Individuals with oculocutaneous albinism suffer many visual disturbances, such as nystagmus, high refractive error, strabismus, amblyopia, and photophobia. Management of these patients is geared towards improving quality of life. When common treatment options such as spectacles, soft toric contact lenses, or small diameter GP lenses are not successful, a scleral lens can provide improvements in visual acuity while maintaining comfortable and functional vision. ● Scleral lenses vault the cornea to mask high corneal astigmatism and move with the eyes to maintain alignment with the optical axis to increase visual potential for patients suffering from nystagmus ● Although fitting large diameter gas permeable lenses can more difficult with children due to their limited experience with contact lens handling and care, it should not be ruled out when the benefits outweigh the possible difficulties. References: 1. Blachford SL A: The Gale Encyclopedia of Genetic Disorders. Gale Group-Thompson Learning, Detroit, MI; 2002. 2. Biousse, V., R. J. Tussa, B. Russell, M. S. Azran, and V. Das. "The Use of Contact Lenses to Treat Visually Symptomatic Congenital Nystagmus." J Neurol Neurosurg Psychiatry (2004);75:314-316. Web 3. Ehlers, Justis P., and Chirag P. Shah. "Albinism." The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease. Philadelphia: Lippincott Williams & Wilkins, 2008. N. pag. Print. 4. Lahnstein, Carrie, Harold Bedell, and Karen Fern. "Improved Visual Acuity And Decreased Eye-Movement Intensity In A Patient With Nystagmus During RGP Lens Wear." Optometry and Vision Science 78.SUPPLEMENT (2001): 155. Web. 5. "Oculocutaneous Albinism." Genetics Home Reference. US National Library of Medicine, 24 Aug. 2015. Web. 25 Aug. 2015. 6. Okulicz JF, Shah RS, Schwartz RA, Janniger CK. Oculocutaneous albinism. J Eur Acad Dermatol Venereol. 2003 May;17(3):251-6. Review. 7. Omar, R., S. S. Idris, C. K. Meng, and F. V. Knight. Management of Visual Disturbances in Albinism: A Case Report. Rep. N.p.: n.p., n.d. J Med Case Reports, 19 Sept. 2012. Web.