Clinical Characteristics and Low Vision Rehabilitation Methods for Partially Sighted School-Age Children

Causes of low vision in children: A systematic review

OBJECTIVE

To identify the ocular pathologies that are reported as causes of low vision in children.

MATERIAL AND METHODS

The systematic search was carried out in Medline (PubMed), Embase and Lilacs. Observational studies with populations between 0-18 years of age, reporting visual acuity data between 20/60-20/400 and reporting the frequency of ocular pathologies were selected. Studies in which the diagnosis of the condition had not been verified by a professional, or which covered only cases of blindness, uncorrected refractive errors, or amblyopia, were excluded. The methodological quality of the articles was evaluated using the Joanna Briggs Institute instrument for prevalence studies.

RESULTS

27 studies conducted in Asia (13 publications), Africa (6 studies), Oceania (4 studies), Europe and South America (2 studies each) were included. The most reported causes of low vision were: cataract, with prevalence between 0.8% and 27.2%; albinism with from 1.1% to 47%; nystagmus, with prevalence between 1.3% and 22%; retinal dystrophies between 3.5% and 50%; retinopathy of prematurity (ROP) with prevalence between 1.1% and 65.8%, optic atrophy between 0.2% and 17.6%, and glaucoma from 2.4% to 18.1%.

CONCLUSIONS

Cataract, albinism and nystagmus are the ocular pathologies most mentioned by studies as a cause of low vision in children, as well as retinal diseases such as ROP and optic nerve diseases such as atrophy. However, there are numerous eye conditions that can result in low vision in the pediatric population.

Preference of low vision devices in patients with central field loss and peripheral field loss

PURPOSE

The objective of this study was to estimate the profile of patients visiting low vision care clinic at a tertiary eye care center in India and to analyze the preference of low vision devices (LVD).

METHODS

A retrospective review was done for 450 patients with low vision who were referred to the LVC clinic from January 2019 to December 2019. The participants were categorized into two groups as central field loss (CFL) and peripheral field loss (PFL). Demographic profile details and low vision device preference were documented.

RESULTS

Out of 450 patients, 242 (53.8%) were diagnosed to have CFL and 208 (46.2%) had PFL. The median age of the overall patients was 34.5 years. Overall, 323 (71.8%) were men and 127 (28.2%) were women. Cone dystrophy (21.1%) was the major cause of low vision among atrophic changes (54.1%) in CFL, and retinitis pigmentosa (81.2%) was the majority in retina related changes (81.7%) in PFL. Overall, 71.3% of the low vision patients preferred LVD. CFL group (76%) preferred LVD more than PFL group (65.9%). Almost 34% of the patients in both CFL and PFL group have preferred half eyes and Ashperics, followed by 32.5% in CFL and 28.1% in PFL preferred dome magnifiers. Statistically significant improvement in distance and near vision with the help of LVD was noted.

CONCLUSION

The use of LVD can help patients with low vision in restoring useful vision, where medical and surgical treatment have no or a limited role.

Is the high contrast visual acuity chart a good predictor of improvement in visual acuity with low vision aids?

Purpose:

To assess whether the objective improvement seen with HCVA chart using LVAs correlates with subjective improvement in the quality of life as measured on low vision quality of life (LVQOL) questionnaire of such patients.

Methods:

This was a prospective, consecutive, observational study. Objective improvement in visual function was assessed using LVAs with high contrast LogMAR visual acuity chart for near and distance. Subjective improvement for distance was assessed using LVQOL score for “distance mobility and lighting”, whereas for near it was assessed using the LVQOL score for “near and fine work”. A total of 46 patients completed one follow-up after low vision trial and were included in the study.

Results:

Improvement in objective visual acuity was highly significant for both near and distance (P < 0.001) with LVAs. LVQOL score improved from 65.85 to 76.83 after one of using low vision aids (P < 0.001). The improvement in LVQOL score for distance and mobility was also highly significant (2.55; P < 0.001); and so was for near and fine work (5.89; P < 0.001). However, Spearman rank correlation coefficient showed no correlation between improvement in visual acuity for distance and LVQOL score improvement for distance (r_s = –.086; P = 0.57). For near also, improvement in acuity did not correlate with the LVQOL score improvement for near and fine work (r_s = 0.036; P = 0.81).

Conclusion:

No statistical correlation was observed between the improvements measured by objective HCVA charts and subjective improved as perceived by the patient after use of low vision devices.

Causes of severe visual impairment in infants and methods of management

OBJECTIVES

To examine the causes of severe visual impairment (SVI) in infants below the age of 2 years and to review management methods.

METHODS

The data of 2657 patients followed between January 2014 and July 2019 were reviewed, and 148 (5.6%) infants who had SVI were enrolled. Data including age, gender, affected anatomical site, diagnosis, presence of any non-ophthalmological deficiencies, and methods of management were reviewed. The diagnoses were investigated in the categories of avoidable and unavoidable basis. The methods of management were analysed from the perspective of low vision habilitation.

RESULTS

The mean age at first eye examination was 6.61 ± 5.25 months, and 84 (56.7%) infants were male. Of the 148 infants, 69 (46.6%) were premature. Cerebral visual impairment (CVI) was the most common diagnosis in both preterm (39.1%) and term (11.4%) infants. Delayed visual maturation, optic nerve pathologies, oculocutaneous albinism, and congenital cataract were the other frequent causes. The rate of multiple disabilities was 30% in the whole group and 94% in infants with CVI. Most of the babies had a normal-appearing globe (43.3%). Retina was affected in 23.7% of the infants. Avoidable causes were identified in 79.7% of the infants. The used methods of management were optic interventions, visual stimulation therapy, medical and/or surgical treatment.

CONCLUSIONS

CVI was found the most common cause of SVI in both preterm and term-born infants, and the higher rate of multiple disabilities in these infants was remarkable. Optic interventions and visual stimulation therapy were the most common methods of management.

The efficacy of low vision aids with contact lenses in pediatric population

PURPOSE

To compare the efficacy of contact lens use with low vision aids (LVA) with the efficacy of spectacle use with low vision aids.

METHODS

Thirty-six pediatric patients with low vision were enrolled in this study between January 2015 and March 2017. The patients were examined for best-corrected visual acuity (BCVA) with spectacles, spectacles with LVA, contact lenses and contact lenses with LVA. Toleration of the patients with contact lenses and LVA were recorded at the final follow-up exam.

RESULTS

The mean BCVA with spectacles was detected as 1.11 ± 0.25 log MAR and the mean BCVA improved to 0.35 ± 0.13 log MAR with the use of spectacles and LVA, which was statistically significant. The mean BCVA with contact lens, which was 0.99 ± 0.22 log MAR, improved to 0.40 ± 0.21 log MAR with contact lens and LVA, which was also significant. There was a statistically significant improvement in BCVA of the patients with contact lenses only when compared to spectacles only. The mean BCVA significantly improved in patients using LVA with contact lenses when compared to LVA with spectacles. Tolerations of the patients with contact lenses and LVA were found to be well at 29 of 36 (80.55%) at final follow-up (26.11 ± 6.85 months).

CONCLUSION

Contact lens use in pediatric patients with low vision especially with LVA offers better visual acuity, a decrease in nystagmus amplitude, wider field of view and comfort.

Low vision services: a practical guide for the clinician

Low vision has been defined by best-corrected visual acuity worse than 20/40 in the better eye, substantial visual field loss, or substantial loss of contrast sensitivity that cannot be corrected by refraction, medical treatment, or surgery. In the United States, low vision is most commonly caused by age-related macular degeneration, glaucoma, and diabetic retinopathy. Most patients with low vision are elderly, although patients of all ages – including pediatric patients – may be affected. Low vision may decrease a patient’s quality of life substantially, leading to emotional distress and possibly depression. Low vision specialists aim to maximize the remaining vision of a patient by providing optical aids, orientation and mobility training, psychosocial support, and other methods of rehabilitation. Innovations in technology and devices offer additional options in low vision rehabilitation. Clinicians should consider referral to low vision specialists when a patient has difficulty with reading, mobility, driving, recognizing faces, or suffers from emotional distress due to low vision. Early referral may lead to improved outcomes.

Results of Screening in Schools for Visually Impaired Children

Objectives:

The aim of this study was to identify the causes of visual impairment in children attending schools for students with visual impairment and to identify children suitable for treatment and rehabilitation.

Materials and Methods:

All students were examined in our department by a pediatric ophthalmologist and an ophthalmologist experienced in low vision and visual rehabilitation. The children’s medical histories were recorded. All children underwent ophthalmological examination including visual acuity measurement, anterior segment and dilated fundus evaluation, retinoscopy with cycloplegia, and intraocular pressure measurement. The causes of visual impairment were grouped as avoidable and unavoidable. Children with residual visual acuity better than 20/1250 were included in the low vision rehabilitation programme.

Results:

A total of 120 patients were evaluated and 79.2% were legally blind (visual acuity less than 0.05), 18.4% had low vision (visual acuity between 0.05 and 0.3), and 0.8% had normal vision (>0.3). The main causes of visual impairment were retinal dystrophies (24.2%) and retinopathy of prematurity (17.5%). Of all diseases related to visual impairment, 27.6% were avoidable. Improvement in visual acuity was achieved with low vision aids in 57.5% of all patients.

Conclusion:

The incidence of visual impairment due to avoidable causes can be decreased by ophthalmic screening. Treatment of these children in the early stages of visual development can improve visual acuity. Even in cases with delayed diagnosis, low vision aids are important for visual and neurobehavioral development, and these programmes may improve quality of life and education in these children.