Abstract
Purpose:
Relationship between cone photoreceptor distribution and aging is unclear. We used adaptive optics fundus camera to examine cone photoreceptor distribution in the macular area of aged patients and quantitatively analyzed its relationship with age, axial length, and age-related maculopathy for the first time to our knowledge.
Methods:
Sixty-three cases aged 50 or older with unilaterally affected macular diseases were included. Thirty-five cases (54%) were affected by neovascular age-related macular degeneration (AMD). The unaffected eye was examined with adaptive optics fundus camera (rtx1TM, Imagine Eyes, France) and high-resolution retinal images with cone photoreceptor mosaic were obtained. After excluding the eyes with any pathological findings within the area of interest, averaged cone packing density and spacing at 2° superior and 5° temporal to the fovea were calculated. Relationships between these values and age, axial length, AMD or non-AMD in the affected eye, drusen or pigment abnormality in the measured eye were analyzed. Amongst 24 eyes were repeatedly examined for testing repeatability.
Results:
Patient age ranged 50 to 77, and axial length 21.7 to 27.5 mm. At 2° superior (n=51) and 5° temporal (n=53) to the fovea average cone packing density were 19,200 ± 591 and 13,700 ± 386 (cells/mm2), and average cone spacing were 8.10 ± 0.14 and 9.56 ± 0.16 (μm), respectively. Axial length was significantly correlated with the density and the spacing (-1,360 and -1,080 cells/mm2/mm, 0.32 and 0.42 μm/mm at 2° superior and 5° temporal, respectively). Age was significantly correlated with the density at 5° temporal (-130 cells/ mm2/year), and this correlation was also observed when the density was calculated as angular density (-9.4 cells/deg2/year). AMD or non-AMD in the contralateral eye and degrees of drusen or pigment abnormality in the measured eye was not significantly associated with the density or the spacing. Intraclass correlation coefficients (%) for the density and the spacing were 95 and 94 at 2° superior, 90 and 91 at 5° temporal, respectively.
Conclusions:
Axial length and age were significantly correlated with cone photoreceptor distribution in aged patients. Patient’s background disease or degrees of drusen or pigment abnormality might not affect them. Influence of axial length and age should be considered when analyzing cone distribution in aged patients.
Keywords: 412 age-related macular degeneration •
413 aging •
550 imaging/image analysis: clinical