title: Photoreceptor dysfunction in early and intermediate age-related macular degeneration assessed with mfERG and spectral domain OCT.
abstract: OBJECTIVE
  To evaluate the changes of the photoreceptor layer (PRL) thickness with spectral domain optical coherence tomography (SD-OCT) and the retinal function by mfERG, as well as the correlation of morphology and function parameters in subjects with early and intermediate age-related macular degeneration (AMD).
  
  
  METHODS
  Subjects with clinical diagnosis of early or intermediate AMD and age-matched healthy subjects were recruited prospectively in this study. Color fundus photography, SD-OCT, and mfERG were conducted. Retinal photoreceptor thickness was measured, and first-order kernel responses were recorded. The differences between AMD group and control group were compared, and the correlations between macular photoreceptor thickness and the mfERG were analyzed.
  
  
  RESULTS
  PRL thickness (μm) in four areas including foveola and 0.5, 1.5, and 3 mm away from foveola was 192.48 ± 17.37, 163.73 ± 12.95, 130.93 ± 9.20, and 108.78 ± 7.81, respectively, in normal eyes, whereas in AMD group, they were 158.61 ± 45.25, 138.91 ± 20.92, 118.91 ± 12.85, and 95.00 ± 9.64, respectively (P < 0.001). The mean amplitude response densities of AMD patients decreased significantly compared to the control group in ring 1-6 (P < 0.001). The mean mfERG N1 and P1 latency of AMD patients prolonged compared to the control group, except the ring 1 (P = 0.588 and P = 0.084). The macular PRL thickness was significantly associated with the mfERGN1 and P1 amplitude density in ring 1-4 (r = 0.338-0.533, P < 0.01).
  
  
  CONCLUSIONS
  PRL thickness decreases are in accordance with the deterioration of retinal electrophysiological activity. The retinal PRL thickness is important parameter to assess of early and intermediate AMD severity.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060, China.
authors.forename: Shasha
authors.initials: S
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060, China.
authors.forename: Chengguo
authors.initials: C
authors.lastname: Zuo
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Mi
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060, China.
authors.forename: Guangwei
authors.initials: G
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060, China. liuxing@mail.sysu.edu.cn.
authors.forename: Xing
authors.initials: X
authors.lastname: Liu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004596:Electroretinography / Q000379:methods*; D005260:Female; D057092:Geographic Atrophy / Q000145:classification / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology*; D011446:Prospective Studies; D012160:Retina / Q000503:physiopathology*; D015593:Retinal Drusen / Q000503:physiopathology; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D057135:Wet Macular Degeneration / Q000145:classification / Q000503:physiopathology*
keywords: Age-related macular degeneration; Drusen; Multifocal electroretinography; Optical coherence tomography; Photoreceptor