Several neurological pathologies affect visual functions (transitorily or permanently). However, the magnitude and epidemiological behavior of these as potential causes of low vision and blindness are unknown. This study aims to characterize patients clinically and epidemiologically with visual impairment secondary to neuro-ophthalmologic alterations treated in neuro-ophthalmologic consultation in a reference center in Medellín.
A retrospective cross-disciplinary study that assesses the patients with visual impairment secondary to neuro-ophthalmologic alterations treated in neuro-ophthalmologic consultation between 2015 and 2018.
Of 3313 clinical records reviewed, 140 patients met the eligibility criteria. Median age of diagnosis was 47 years of age (RI: 37.5–45.7) due to its heterogeneous distribution it was determined to group them into those under 18 years of age (35/140; 25%) and adults (105/140; 75%). 108/140 (77.1%) patients had non-ophthalmologic comorbidities, being the cardiovascular disease the most frequent. The main and more prevalent neuro-ophthalmologic diagnosis was optic atrophy (112/140; 80%). According to the visual deficiency category, the majority (61/140; 43.6%) presented a moderate visual deficiency. In adults, moderate visual deficiency was the most frequent, while in the group under 18 years of age, it was blindness. 41/140 (29.3%) were on a visual rehabilitation process and only 3/140 (2.1%) of them had disability certificates.
In this cohort, it is observed that neurological alterations are etiologies of permanent visual deficiencies leading to visual impairment, being optic atrophy, the main neuro-ophthalmologic cause identified, causing in most cases, moderate visual deficiency in adults and blindness in individuals under 18 years of age .
caracterizar clínica y epidemiológicamente pacientes con discapacidad visual secundaria a alteraciones neuro-oftalmológicas atendidos en la consulta de neuro-oftalmología en un centro de referencia de la ciudad de Medellín.
estudio transversal retrospectivo que evaluó los pacientes con discapacidad visual secundaria a alteraciones neuro-oftalmológicas atendidos en consulta de neuro-oftalmología entre 2015 y 2018.
se evaluaron 3.313 historias clínicas, de las cuales 140 pacientes cumplieron los criterios de elegibilidad. La mediana de edad al diagnóstico fue 47 años (RI: 37,5 – 45,7), debido a su distribución heterogénea se decidió agrupar en menores de 18 años (35/140; 25%) y adultos (105/140; 75%). 108/140 (77,1%) pacientes tenían comorbilidades no oftalmológicas, siendo la enfermedad cardiovascular la más frecuente. El diagnóstico neuro-oftalmológico principal más prevalente fue la atrofia óptica presentado en 112/140 (80%) de los pacientes, de las cuales 74/112 (66%) era atrofia óptica no especificada. Según la categoría de la deficiencia visual, la mayoría (61/140; 43,6%) presentaban deficiencia visual moderada, seguido de ceguera (43/140; 30,7%) y deficiencia visual grave (36/140; 25,7%). En los adultos, la deficiencia visual moderada fue la más frecuente, mientras que, en los menores de 18 años, fue la ceguera. Respecto a las ayudas ópticas y no ópticas, la mayoría usaban gafas especiales (36/140; 25,7%), 41/140 (29,3%) se encontraban en rehabilitación visual, y sólo 3/140 (2,1%) tenían certificados de invalidez.
en esta cohorte de pacientes se observa que las alteraciones neurológicas constituyen una importante etiología de discapacidad visual, siendo la atrofia óptica la principal causa neuro-oftalmológica generando en su mayoría deficiencia visual moderada en adultos y ceguera en menores de 18 años. Finalmente, se evidenció que menos de la mitad de los pacientes con este diagnóstico asisten a programas de rehabilitación visual.
The visual system, in addition to the eyeball, includes the visual pathway and several brain structures that support visual functions such as visual acuity, color vision, stereopsis, contrast sensitivity, and the visual field.
In the framework of human functioning, disability results from the interaction between deficiencies, in which are included physical and social barriers of each individual, creating limitations in activity and restrictions in participation. , Among the disability categories, visual impairment can be found, including low vision and blindness. , Visual deficiencies are produced when a condition or disease affects a component of the visual system and one or more of the visual functions.
A prevalence of 43 million blind people and 295 million with low vision was reported in 2020, and it was also reported in the period between 1990 and 2020, the number of blind and low vision people increased by 50.6% and 91.7%, respectively. According to global forecasts, due to the population growth of 38% and population aging, it is expected that these figures increase by a factor of 3 by 2050.
Visual impairment can be created due to ophthalmologic or neurological causes, that include injuries in the visual pathway such as optic nerve, chiasm, optic tracts, geniculate body of the visual thalamus, optic radiations, among others.
In 2020, the main causes of blindness reported were the following: cataracts, uncorrected refractive errors, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy; the main causes of low vision reported are: uncorrected refractive errors (157 million), cataracts (83.4 million), AMD (6.2 million), glaucoma (4.1 million), and diabetic retinopathy (3.28 million). In medium- and low-income countries, cataracts are still the main cause of blindness.
Despite all above-mentioned etiologies, which are of optical and ophthalmologic nature, studies describing and characterizing the neuro-ophthalmologic causes of visual impairment are limited. Neurological pathologies affect visual functions, including optic neuritis, ischemic, traumatic, and compressive optic neuropathy. However, the magnitude and epidemiological behavior of these as potential causes of low vision and blindness are unknown.
The World Health Organization (WHO) reports approximately 1 billion people worldwide with neurological disorders, a figure that corresponds to 15% of the world’s population. Most neurological disorders may involve ganglion neurons, photoreceptors, or visual pathway, and therefore, have been considered irreparable due to the general belief that nerve tissue does not regenerate or recover, oftentimes unaware that functional rehabilitation programs can be offered based on residual or potentially usable vision. Hence, these etiologies transcend ophthalmology and optometry and represent diagnostic, therapeutic, and rehabilitation challenges.
A search carried out in Antioquia (department located in Colombia), reports 110 250 people with disabilities, 32% presented some neurological alteration, but without reference to visual impairment of neurological origin. Additionally, a study executed by our research group, indicated that among the causes of visual impairment, 20.9% corresponded to neuro-ophthalmologic causes and 17.2% to neurological causes. This boosted the need to deepen regarding the neuro-ophthalmologic etiology that creates visual deficiencies and visual impairment.
This study aims to characterize patients clinically and epidemiologically with visual impairment secondary to neuro-ophthalmologic alterations treated in neuro-ophthalmologic consultation in a reference center in Medellín between 2015 and 2018.
Study design and population
A retrospective observational study, composed of visually impaired patients secondary to neuro-ophthalmologic alterations, treated in neuro-ophthalmologic consultation of a reference center in Medellín, Colombia between 2015 and 2018.
The inclusion criteria were patients with diagnosis of neuro-ophthalmologic alterations and presence of any permanent visual deficiency in visual acuity or visual field, according to WHO definition. Patients with incomplete clinical records of variables relevant to the study, such as visual acuity and main neuro-ophthalmologic diagnosis, were excluded.
The data contained in the WHO in the International Classification of Diseases-ICD10R and ICD-11 were considered, where low vision and blindness are defined in terms of the classification of visual acuity (VA) ranges: low vision is equivalent to a best-corrected VA worse than 20/60 but equal or better than 20/400 in the better eye, or visual field loss corresponding to less than 20° in the better eye, with the best possible correction; and blindness is a VA worse than 20/400 or visual field loss corresponding to less than 10°.
Once approval was obtained from the participating institution for accessing the clinical records, data collection process began, starting with the review of those clinical records that met the eligibility criteria. A pilot test was conducted with 20 clinical records that allowed modification of the instrument.
The variables assessed were sociodemographic (age at main diagnosis and sex), clinical (main neuro-ophthalmologic diagnosis, category of visual deficit), records (non-ophthalmologic comorbidities, family history of ophthalmologic diseases), and use of optical and or non-optical aids (special glasses, telescopes, magnifying glasses, contact lenses, orientation cane, reading ruler, Braille, software, guide dog, cellphone application, visual rehabilitation).
The information collected was exported to Microsoft Excel (Office 2016 version), where an exploratory analysis was performed to evaluate the quality of the information (missing data, extreme values, among others) and the consistency of the data.
Regarding possible biases and their control, the selection bias of the population was controlled by including the entire population of patients who met the eligibility criteria of the study, based on the clinical history of patients seen by medical subspecialty. Aiming to reduce information bias, a single collection tool was designed, considering the eligibility criteria and the variables required for this research; data that did not match was verified with a new review of the clinical records by one of the researchers.
Quantitative variables were described by the median and interquartile range (IQR) due to the non-compliance with the assumption of normality using the Kolmogorov–Smirnov normality test. Categorical variables were expressed as absolute frequencies and percentages. Since some of the characteristics assessed may vary depending on the age group, the information is described in the total of the group evaluated and according to age categorized as: under 18 years of age and over 18 years of age (greater than or equal to 18). All analyses were performed in IBM SPSS 24.0.
The research was conducted following the guidelines of the 2013 version of the Declaration of Helsinki and Resolution 008430 of 1993 of the Ministry of Health of the Republic of Colombia for which it was considered risk-free research; it was approved by Health Research Ethics Committee of Pontificia Bolivariana university by record no. 2 of February 2017 and the endorsement of the participating reference center was obtained.
A total of 3313 clinical records were assessed, of which 140 (4.22%) patients met the eligibility criteria ( Fig. 1 ). Seventy-two (51.4%) were female, the median age at primary diagnosis was 47 years (RIC: 37.5–45.7); 35/140 (25%) were younger than 18 years of age and 105/140 (75%) were adults.
Concerning the presence of non-ophthalmologic comorbidities, 108/140 (77.1%) patients had some comorbidity, the most frequent being a circulatory system disease. In adults, circulatory system diseases were most common in 39/84 (46.4%) patients, followed by endocrinological diseases, 29/84 (34.5%), while in minors, the most frequent was neurological disease in 10/24 (41.6%) patients ( Table 1 ).
|Non-ophthalmologic comorbidities||Total||< 18 years||Adults|
|(n = 108)||(n = 24)||(n = 84)|
|n (%)||n (%)||n (%)|
|Cardiovascular system disease||41 (37.9)||2 (8.3)||39 (46.4)|
|Endocrine disease||34 (31.5)||5 (20.8)||29 (34.5)|
|Neurological disease||27 (25)||10 (41.6)||17 (20.2)|
|Sensory organ disease||15 (13.9)||2 (8.3)||13 (15.5)|
|Respiratory system disease||13 (12.03)||5 (20.8)||8 (9.5)|
|Mental disease||11 (10.2)||1 (4.2)||10 (11.9)|
|Locomotive system disease||11 (10.2)||3 (12.5)||8 (9.5)|
|Digestive system disease||8 (7.4)||2 (8.3)||6 (7.4)|
|Neoplasm||6 (5.5)||2 (8.3)||4 (4.8)|
|Autoimmune disease||5 (4.6)||2 (8.3)||3 (3.6)|
|Genitourinary system disease||5 (4.6)||1 (4.2)||4 (4.8)|
|Injuries, wounds, and other external factors||5 (4.6)||0||5 (5.9)|
|Genetic disease||3 (2.8)||3 (12.5)||0|