Abstract
Retinitis pigmentosa (RP) is a slowly progressive, inherited retinal degeneration affecting roughly 1 in 4000 people, typically resulting in a loss of peripheral and night vision, with most legally blind by age 40[1] . RP is characterized by the apoptosis of retinal rods and cones (photoreceptors). Cones are responsible for central and color vision, while rods provide peripheral and nighttime vision. Over 20 years ago, it was reported that some RP patients initially lose short wavelength cones (i.e., s-cones for blueviolet colors; e.g., imagine a world in which shades of blue look grey), but no further research on this topic has been conducted. We explored factors that may predict which RP patients are susceptible to scone loss. Cone function was determined using the PC-based Innova Rabin Cone Contrast Test with 2 tests per session repeated at two visits. Of 18 RP patients tested, only three (17%) had normal s-cone sensitivity, while 14 out of 15 eyes (93%) in 10 patients with measurable s-cone loss had a greater reduction in sensitivity for the s-cones than longer wavelength cones for red and green colors. S-cone sensitivity loss was measurable in those with visual acuities between 20/25-20/50. Amount of peripheral visual field loss, ability to see stars as a child, and duration of night vision loss were not statistically significantly related to s-cone loss across subjects; however, the three participants with normal s-cone sensitivity were the only ones with rod-mediated night vision, indicating there may be a link between loss of rods and s-cones.
Faculty Sponsors
Ava Bittner, O.D., Ph.D., Mark Jaffe, D.P.M.
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-10-2015 1:00 PM
End Date
4-10-2015 5:30 PM
Why do Patients Who Are Going Blind Lose Their Blue Color Vision First?
Alvin Sherman Library
Retinitis pigmentosa (RP) is a slowly progressive, inherited retinal degeneration affecting roughly 1 in 4000 people, typically resulting in a loss of peripheral and night vision, with most legally blind by age 40[1] . RP is characterized by the apoptosis of retinal rods and cones (photoreceptors). Cones are responsible for central and color vision, while rods provide peripheral and nighttime vision. Over 20 years ago, it was reported that some RP patients initially lose short wavelength cones (i.e., s-cones for blueviolet colors; e.g., imagine a world in which shades of blue look grey), but no further research on this topic has been conducted. We explored factors that may predict which RP patients are susceptible to scone loss. Cone function was determined using the PC-based Innova Rabin Cone Contrast Test with 2 tests per session repeated at two visits. Of 18 RP patients tested, only three (17%) had normal s-cone sensitivity, while 14 out of 15 eyes (93%) in 10 patients with measurable s-cone loss had a greater reduction in sensitivity for the s-cones than longer wavelength cones for red and green colors. S-cone sensitivity loss was measurable in those with visual acuities between 20/25-20/50. Amount of peripheral visual field loss, ability to see stars as a child, and duration of night vision loss were not statistically significantly related to s-cone loss across subjects; however, the three participants with normal s-cone sensitivity were the only ones with rod-mediated night vision, indicating there may be a link between loss of rods and s-cones.
