Correlation between visual function and photoreceptor inner/outer segment junction in patients with retinitis pigmentosa.
OBJECTIVE
To determine whether a significant correlation exists between the visual acuity or foveal thickness and the status of the inner and outer segment junction (IS/OS) of the photoreceptor in patients with retinitis pigmentosa (RP).


METHODS
Three hundred eyes of 163 patients with RP were examined with the optical coherence tomography (OCT). The IS/OS appeared as a distinct, highly reflective line just vitread of the retinal pigment epithelium in the OCT3 images. The IS/OS line was graded into three groups. The correlations between the grade of the IS/OS and age, best-corrected visual acuity (BCVA), and central foveal thickness (CFT) were determined.


RESULTS
Grade 1 included 93 eyes (31.0%) in which an IS/OS line was not seen, Grade 2 included 67 eyes (22.3%) with an abnormal IS/OS, and Grade 3 included 140 eyes (46.7%) with a normal IS/OS. The correlation between the IS/OS grade and age was not significant (P=0.5536). The IS/OS grade was significantly correlated with BCVA and CFT (both P<0.0001). The BCVA was significantly better in Grade 3 eyes than Grades 1 and 2 (both P<0.0001). The CFT was significantly thinner in Grade 1 eyes than in Grades 2 and 3 (both P<0.0001). In Grade 3, the mean length of the IS/OS was 2.51+/-1.42 mm (+/-SD). The length of the IS/OS was significantly correlated with the BCVA (P<0.0001, r=-0.375).


CONCLUSIONS
The presence of the IS/OS was associated with better visual acuity and thicker fovea in RP patients. The absence of an IS/OS may reflect a foveal dysfunction in RP patients.
Aizawa
S
S
Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Japan.
Mitamura
Y
Y
Baba
T
T
Hagiwara
A
A
Ogata
K
K
Yamamoto
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005584:Fovea Centralis / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D055211:Retinal Photoreceptor Cell Inner Segment / Q000473:pathology*; D055214:Retinal Photoreceptor Cell Outer Segment / Q000473:pathology*; D012174:Retinitis Pigmentosa / Q000473:pathology* / Q000503:physiopathology; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult