June 2021
Volume 62, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2021
Dark-adapted visual fields (DAVF) in patients with two disease-causing variants in USH2A
Author Affiliations & Notes
  • David G Birch
    Retina Foundation of the Southwest, Dallas, Texas, United States
  • Lassana Samarakoon
    Jaeb Centre for Health Research, Tampa, Florida, United States
  • Laura E Bocchino
    Jaeb Centre for Health Research, Tampa, Florida, United States
  • B. Michele Melia
    Jaeb Centre for Health Research, Tampa, Florida, United States
  • Jacque L Duncan
    University of California San Francisco, San Francisco, California, United States
  • Allison Ayala
    Jaeb Centre for Health Research, Tampa, Florida, United States
  • Isabelle Audo
    Institut de la vision, Paris, Île-de-France, France
    Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, Île-de-France, France
  • Janet K Cheetham
    Foundation Fighting Blindness Inc, Columbia, Maryland, United States
  • Todd Durham
    Foundation Fighting Blindness Inc, Columbia, Maryland, United States
  • Alessandro Iannaccone
    Duke University, Durham, North Carolina, United States
  • Mark E Pennesi
    Oregon Health & Science University, Portland, Oregon, United States
  • Katarina Stingl
    Universitatsklinikum Tubingen Universitats-Augenklinik, Tubingen, Baden-Württemberg, Germany
  • Footnotes
    Commercial Relationships   David Birch, AGTC (C), AGTC (F), Biogen (F), Editas (C), Iveric (C), Nacuity (C), ProQR (C), ProQR (F), Roche-4D (C), Roche-4D (F); Lassana Samarakoon, None; Laura Bocchino, None; B. Melia, None; Jacque Duncan, 4D Therapeutics (C), Acucela (F), AGTC (C), Allergan/Abbvie (F), Astellas (C), Biogen/Nightstarx Therapeutics (F), DTx Therapeutics (C), Editas (C), Eloxx (C), Eyevensys (C), Gyroscope (C), Horama (C), Neurotech USA (F), ProQR Therapeutics (C), Second Sight Medical Products (F), Sparing Vision (C), Spark Therapeutics (C), Spouse- RxSight (I), Vedere Bio (C); Allison Ayala, None; Isabelle Audo, Agence Nationale de la Recherche within the Investissements d'Avenir program [ANR-11-IDEX-0004-0] (F), Biogen (C), Foundation Fighting Blindness (F), Gamut Tx (C), IHU FOReSIGHT [ANR-18-IAHU-0001] (F), LABEX LIFESENSES [reference ANR-10-LABX-65] (F), MeiraGTX (C), Novartis (C), Retina France (F), Roche (C); Janet Cheetham, Abbvie (I); Todd Durham, None; Alessandro Iannaccone, Acucela (F), Alia Therapeutics (S), Allergan/ Retrosense (F), Applied Genetic Technologies (C), Applied Genetic Technologies (F), Astellas (C), ClearView Healthcare Partners (C), Editas Medicine (C), Endogena (C), Evolution Medical (C), Frontera Therapeutics (C), GLG Group (C), Guidepoint Clinical (C), Gyroscope (C), Huron Consulting Group (C), IQVIA (C), Kairos Ventures (C), Rhythm Pharmaceuticals (C), Riovant Pharma (C), Teladoc Health (C); Mark Pennesi, Adverum (C), AGTC (C), Allergan/Editas (C), Astellas Pharmaceuticals (C), Astena (C), Biogen (C), Blue Rock (C), DTx (C), Endogena (C), Eyevensys (C), Gensight (C), Horama (C), Iveric (C), Nacuity Pharmaceuticals (C), Novartis (C), Nyan (C), Ocugen (C), Ora (C), ProQR Therapeutics (C), RegenexBio (C), Roche (C), Sanofi (C), Sparing Vision (C), Vedere (C), Viewpoint Therapeutics (C); Katarina Stingl, Novartis (F), ProQR (F)
  • Footnotes
    Support  Foundation Fighting Blindness
Investigative Ophthalmology & Visual Science June 2021, Vol.62, 3241. doi:
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      David G Birch, Lassana Samarakoon, Laura E Bocchino, B. Michele Melia, Jacque L Duncan, Allison Ayala, Isabelle Audo, Janet K Cheetham, Todd Durham, Alessandro Iannaccone, Mark E Pennesi, Katarina Stingl; Dark-adapted visual fields (DAVF) in patients with two disease-causing variants in USH2A. Invest. Ophthalmol. Vis. Sci. 2021;62(8):3241.

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      © ARVO (1962-2015); The Authors (2016-present)

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Purpose : To identify and measure rod-mediated visual field thresholds using two-color dark-adapted chromatic (DAC) perimetry in a subset of participants in the RUSH2A study, determine the percentage of participants that retain rod function, and explore the relationship between dark adapted visual fields (DAVF) from DAC perimetry and parameters of rod function from electroretinogram (ERG) and full-field stimulus thresholds (FST).

Methods : At 6 sites, participants from the Rate of Progression of USH2A-related Retinal Degeneration (RUSH2A) 4-year natural history study of Usher syndrome type 2 (USH2) and non-syndromic autosomal recessive retinitis pigmentosa (ARRP) were invited to participate in the DAVF ancillary study. Dark-adapted retinal sensitivity was tested using cyan and red test protocols on the DAC perimeter (Medmont), and loci where cyan relative to red sensitivity was > 5 dB were considered rod mediated. Measures of full-field rod mean sensitivity, number of rod loci, maximum sensitivity, DAVF full-field hill of vision (DAVF VTOT), and 30-degree hill of vision (DAVF V30) were determined. Correlations between DAVF measures and standard clinical measures were estimated, as were kappa statistics (κ) for agreement between DAVF and other modalities regarding evidence of rod function.

Results : 49 participants (55% female, 95% white) were screened for DAVF rod function; 38/49 (78%) were found to have evidence of rod function. For comparison, 15/49 (31%) had measurable rod ERGs. For those 40 years of age or older, 7 with unmeasurable ERGs retained some rod visual field. DAVF maximum sensitivity was highly correlated with FST white thresholds (ρ=-0.80, p ≤0.001). DAVF mean sensitivity, DAVF VTOT, and DAVF V30 were more moderately correlated with FST white thresholds (ρ=-0.71, -0.72, and -0.61, respectively; all p ≤0.001). Agreement regarding evidence of rod function with DAVF was relatively poor for both FST white (κ=0.35, 95% CI= [0.14,0.57]) and ERG Rod B-Wave (κ=0.16, 95% CI= [0.004,0.31]).

Conclusions : Our results suggest rod-mediated function is present in many patients with symptomatic USH2A-related retinal degeneration, including many without measurable rod ERGs. FST and DAVF represent two potential measures of rod function suitable for longitudinal measures in clinical trials for inherited retinal degenerations.

This is a 2021 ARVO Annual Meeting abstract.


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