doi: https://doi.org/10.19052/sv.4244 Interdisciplinary management of low vision by degenerative myopia: A case report Manejo interdisciplinario de la baja visión por miopía degenerativa: reporte de caso Karol Yissely Cortés Linares* Luis Héctor Salas Hernández** Received: 04-19-2017 / Accepted: 09-22-2017 ABSTRACT Vision is the motor that drives the psychomotor development of a person. The absence or in- adequate interaction with visual stimuli becomes a problem with high emotional, social, and economic repercussions. The diagnosis and treatment of visual or pathological alterations that lead to low vision should be managed by a multidisciplinary team, which includes an optometrist, an ophthalmologist, a psychologist, and a rehabilitator, in order to implement vision stimulation programs and to prescribe non-conventional optical and non-optical aids. In the present case report, the patient was diagnosed with degenerative myopia in both eyes. For this reason, she was referred to low vision assessment and visual rehabilitation. A complete examination was carried out and the existing alternatives for the correction of the problem were analyzed in depth. Finally, a non-conventional optical aid was adapted for far vision —3x telescope— and another one for Keywords: low vision, near vision —1x microscope + 3x magnifying glass—; subsequently, the patient was discharged degenerative myopia, vi- given that the objectives set during the treatment were met. sion, pathology. * Optometrist, MSc in Vision Science, Universidad de La Salle, Bogotá, Colombia. [email protected] ** Optometrist, MSc in Visual Rehabilitation, and Teaching Researcher for the School of Optometry from Universidad Autóno- ma de Aguascalientes, Aguascalientes, México. [email protected]. How to cite this article: Cortés Linares KY, Salas Hernández LH. Interdisciplinary management of low vision by degenerative myopia: A case report. Cienc Tecnol Salud Vis Ocul. 2018;16(1):127-40. doi: https://doi.org/ 10.19052/sv.4244 cien. tecnol. salud. vis. ocul. / vol. 16, no. 1 / enero-junio del 2018 / pp. 127-140 / issn: 1692-8415 / issn-e: 2389-8801 128 RESUMEN La visión es el motor que impulsa el desarrollo psicomotor de las personas. La ausencia o la interacción inadecuada con el estímulo visual se convierten en un problema con altas repercusiones emocionales, sociales y económicas. Las alteraciones visuales o patológicas que conlleven a la baja visión en su diagnóstico y tratamientos deben tratarse por un equipo multidisciplinario, el cual se compone de un optómetra, un oftalmólogo, un psicólogo y un rehabilitador, con el fin de implementar programas de estimulación visual y de prescripción de ayudas ópticas no convencionales y no ópticas. En este reporte de caso, la paciente se diagnosticó con miopía degenerativa en ambos ojos; por tal razón, se remitió a baja visión para valoración y rehabilitación visual. Allí se efectuó un examen completo y se analizaron a profundidad las alternativas existentes para la corrección del caso. Finalmente, se adaptó Cortés Linares KY, Salas Hernández H KY, Cortés Linares Palabras clave: baja vi- una ayuda óptica no convencional para visión lejana —telescopio 3x— y una para visión sión, miopía degenerati- próxima —microscopio 1x + lupa hoja 3x—, con lo cual se dio de alta a la paciente y se va, visión, patología. respondió a los objetivos planteados durante el tratamiento. INTRODUCTION cannot be completely remedied by conventional lenses, contact lenses or medical intervention, The sense of sight is responsible for providing 80 % which lead to restrictions in the performance of the information in the environment required of activities of daily living (ADL). (5) to be able to interact properly with it, giving us autonomy and promoting our development. In It is estimated that approximately 285 million most cases, this development is closely related to people in the world suffer from some kind of visual what we are able to visually understand, so most disability; out of all of them, 245 million have a of the skills that we possess, the knowledge that decreased visual acuity and 39 million suffer from is acquired, and even the activities that we carry blindness (2,6-8). From the total disabled popu- out somehow depend on our visual capacity (1). lation, 1.4 million were children under 15 years old in 2004 (6,9). In addition, the World Health At first, some authors used terms such as severe Organization (WHO) estimates that approximately visual impairment, subnormal vision, partial sight, 1 to 2 million new cases of low vision are detected and residual vision, among others, to define the every year (4). The countries with a better and intermediate space between normal vision and the greater management of low vision patients are total or almost total absence of vision, characteri- the United States and Australia (9). zed by a visual system with irreversible alterations and a loss of visual capacity that constitutes an Surveys carried out in Latin America show that obstacle in the development of people’s lives (2,3). the prevalence of blindness is 3 % in people older than 50 and that the prevalence of low vision is A person with low vision is someone who has a 10 %. There is a great difference in the prevalence functional visual impairment even after treatment of blindness and low vision between urban and or optical correction and who has a visual acuity rural areas, which is 1.4 and 6 %, respectively, in of 6/18, as well as a visual field below 10 degrees, urban areas, as opposed to a prevalence of 4 and who is potentially able to use vision for performing 12 % in rural areas (6). any task (4). Most authors agree on this definition about low vision: According to the WHO (4), a person is conside- red to be legally blind when their visual acuity is Low vision is not a disease, but a condition resul- 20/200 or less in the better-seeing eye after the best ting from an alteration in the visual system, where conventional correction, or when their visual field there is a deterioration of the visual function that is 20° or less in the better-seeing eye. A person is cien. tecnol. salud. vis. ocul. / vol. 16, no. 1 / enero-junio del 2018 / pp. 127-140 / issn: 1692-8415 / issn-e: 2389-8801 identified as having low vision when visual acuity The following charts are used for measuring visual 129 is 20/60 or less after the best correction and their acuity in low vision: visual field is less than or equal to 10°, which res- trains the patient from performing ADL. August • Distant vision: Early Treatment Diabetic Re- Colembrander offers another classification of low tinopathy Study (ETDRS) and Feinbloom. vision according to visual acuity—that is, mode- rate, severe, and profound—, which goes from • Near vision: ETDRS, Colenbrander, Berkeley 20/60 visual acuity to light perception (Table 1). Rudymentary Vision Test (BRVT) and Lea Hyvärinen. table 1. Classification of low vision according to visual acuity by August Colembrander Since low vision cannot be corrected with con- MODERATE SEVERE PROFOUND ventional optical aids, the treatment and visual 20/60-20/160 20/200-20/400 20/500-light perception rehabilitation consists of a set of procedures ai- med at obtaining the maximum possible use of Low vision itself is not a disease, but the result of a the remaining vision by enlarging the size of the pathology, and therefore it cannot be cured without image that is produced in the retina, through treating the main cause of this condition. Some amplification systems; this way, we can stimulate of these pathologies are: Macular degeneration, more retinal cells so that the brain can interpret report myopia: A case vision by degenerative of low management Interdisciplinary retinitis pigmentosa, leucomas, cataract, diabetic this image (10). To determine what type of magni- retinopathy, glaucoma, degenerative myopia (myo- fication and unconventional optic aid the patient pia magna), aniridia, hemianopsia/hemianopia, may need, we must start with the emmetropization and macular hole. of the patient. Two methods are used to determine the refractive status of a patient with low vision: These reasons lead us to understand that a patient with a visual impairment requires a different clini- Radical retinoscopy (objective method): The pro- cal management; as a result, the tests performed cedure will be the same as in a static retinoscopy, during the examination and the measurement the only difference being the working distance of of visual acuity should now cover other needs in the examiner, which is now 33 cm, and the com- terms of size of the stimulus used and separation pensatory working distance lens. The patient is of the characters in the ETDRS chart adapted to asked to keep looking forward. a distance of less than 6 meters (3). To measure visual acuity in patients with low vision, the fo- Noticeable Minimum Difference (NMD) (sub- llowing should be taken into consideration: jective method): This is a subjective retinoscopy method that is used to find the dioptric power of • Distant vision should be tested at 4 m. the sphere, the cylinder and the direction of the axis when static retinoscopy is impossible to do, • Near vision test should be tested at 25 cm. making it difficult to interpret the retinal reflec- tion. To obtain the NMD, the following formula • Allow the patient to move their head as they must be used: please (eccentric vision). snellen denominator • If the patient cannot see the optotypes of the NMD = (1) Testing distance chart at 4 m, proceed to bring it closer to 1 m. • Have patience. 6 m = 30 5 m = 25 reporte de caso cien. tecnol. salud. vis. ocul. / vol. 16, no. 1 / enero-junio del 2018 / pp. 127-140 / issn: 1692-8415 / issn-e: 2389-8801 130 4 m = 20 2.