Higher Retinitis Pigmentosa Rates Seen in Patients with Low Vision, Consanguineous Parents

Retinitis pigmentosa was the main cause of visual impairment among a cohort in which 50% of participants were the offspring of consanguineous marriages, according to a study published in Clinical Optometry.

Researchers retroscopically reviewed the records of 108 participants (mean age 44.64±24.27 years, 56.5% men, 50% consanguineous descent) who were referred to a single center for low vision evaluation between 2014 and 2018. They evaluated patient demographics, family history, and visual acuity (VA), and stratified patients into 1 of 4 groups based on visual impairment: mild (VA <6/12 to ≥6/18), moderate (VA 6/18 to ≥6/60), severe (VA 6/60 to ≥3/60), and blind (VA<3/60).

The average presenting distance VA was 1.25±0.79 logMAR, which improved to 1.06±0.81 logMAR after completing the low vision assessment (P <.05). Patients presented with a mean subjective refraction of −2.51±6.22 D.

Researchers found that 57.4% of participants had moderate visual impairment, 25% had mild impairment, and 11.1% had severe impairment. They classified 6.5% of the cohort as blind.

The team noted that the most common causes of impairment were retinitis pigmentosa (50.0%), diabetic retinopathy (18.75%), myopic degeneration (13.54%), and age-related macular degeneration (12.50%).

Stratified by age group, retinitis pigmentosa was the most common visual impairment among patients aged 18 years or younger (9.40%) and between 19 and 60 years (38.50%). For patients older than 60 years, diabetic retinopathy was the most frequent cause of visual impairment (13.50%).

The most commonly prescribed long-distance visual aids were telescopic and magnification devices, with 89% of these patients reporting improved visual functioning. Patients requiring near vision aids were frequently given spectacle lenses (n=67), with others receiving a closed circuit television or spectacles with a dome magnifier (n=3 for both). A total of 89% of patients requiring devices for near vision also reported improved visual functioning. 

“Low vision clinics should have a holistic approach when addressing visually impaired individuals to cover their physical and psychological needs,” according to the investigators. “Genetic counseling is integral when addressing patients with inherited retinal diseases for instance, as they need guidance concerning consanguinity and family planning.”

Study limitations include a retroscopic nature and single center design.

Reference

Abu-Yaghi N, Meqbil J, Sharif Z, Helwa L, Al-Imam M, Abumanneh Z. Characteristics of visual impairment and the impact of low vision assessment in a tertiary academic hospital in Jordan. Clin Optom. Published online April 15, 2022. doi:10.2147/OPTO.S364010