Background: To determine whether a significant correlation exists among the changes in the size of the abnormal parafoveal autofluorescence ring, the length of the photoreceptor inner and outer segment (IS/OS) junction, and the visual function in patients with retinitis pigmentosa.
Methods: Retrospective observational case series. A total of 50 eyes of 26 patients with typical retinitis pigmentosa and an autofluorescence ring were examined by optical coherence tomography and microperimetry. During the follow-up period of >2 years, the changes in the diameter and area of the autofluorescence ring, the length of the IS/OS line, the best-corrected visual acuity and mean retinal sensitivity in the central 10 degrees were determined.
Results: The diameter and area of the autofluorescence ring, and the length of the IS/OS line decreased significantly during the follow-up period (all, P < 0.0001). The decrease in autofluorescence ring diameter was significantly correlated with the decrease in retinal sensitivity, visual acuity and IS/OS length (P = 0.0105, P = 0.0252 and P < 0.0001, respectively). The decrease in autofluorescence ring area was significantly correlated with the decrease in retinal sensitivity, visual acuity and IS/OS length (P < 0.0001, P = 0.0026 and P = 0.0011, respectively).
Conclusion: During the progression of retinitis pigmentosa, the progressive constriction of the autofluorescence ring reflects the morphological changes of the photoreceptors, and is associated with a worsening of visual function.