{
  "abstract": "Purpose Bi-allelic variants in several rod phototransduction genes give rise to autosomal recessive retinitis pigmentosa (RP) in association with early onset of nyctalopia. Here, we explored visual acuities in patients with RP associated with variants in CNGA1, CNGB1, PDE6A and PDE6B.Methods Patients with RP associated with molecularly confirmed variants in the 4 genes were identified from the electronic patient record of a large inherited retinal disease service. Visual acuity (VA) recorded at the first visit was extracted and comparison was made between the 4 groups, adjusting for age.Results 113 patients had RP associated with CNGA1 (n=14), CNGB1 (n=43), PDE6A (n=16) and PDE6B (n=40). Mean (SD) ages at first visit were 38.6 (12.5), 44.3 (14.9), 34.8 (17.4) and 36.4 (18.0), respectively. Mean logMAR acuities at first visit were 0.099, 0.335, 0.452 and 0.563, respectively. Pairwise age-adjusted comparisons were significant for the following: better acuities were seen for CNGA1 compared with PDE6A (p=8x10-5) and PDE6B (p=0.003); better acuities were also seen for CNGB1 compared with PDE6B (p=0.003). When grouping together CNGA1/B1 and PDE6A/B, patients with CNGA1/B1 had better mean acuity (p=7.5x10-5).Conclusions Cross-sectional and natural history data are important in providing prognostic information and aiding design of future therapeutic trials. Although all of the 4 RP subtypes entail congenital impairment of rod phototransduction, visual acuity appears to be better preserved in variants affecting the rod cyclic nucleotide-gated cation channel compared with those affecting rod phosphodiesterase.",
  "authors": [
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK"
      ],
      "name": "Vishanna Balbirsingh"
    },
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK"
      ],
      "name": "Shaima A Hashem"
    },
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK"
      ],
      "name": "Michalis Georgiou"
    },
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK",
        "University of Manchester, Manchester, UK"
      ],
      "name": "Siying Lin"
    },
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK",
        "Greenwood Genetic Center, South Carolina, USA"
      ],
      "name": "Gavin Arno"
    },
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK"
      ],
      "name": "Mariya Moosajee"
    },
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK"
      ],
      "name": "Andrew R Webster"
    },
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK"
      ],
      "name": "Michel Michaelides"
    },
    {
      "affiliations": [
        "NIHR Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London, UK",
        "Institute of Ophthalmology, University College London, London, UK",
        "Department of Ophthalmology, St Thomas’ Hospital, London, UK"
      ],
      "name": "Omar A Mahroo"
    }
  ],
  "title": "#ECR-Paper-06 Visual acuities in patients with autosomal recessive retinitis pigmentosa associated with mutations in four phototransduction genes",
  "uid": "a758dfc2-448a-5773-b7d4-066d03e7d64a"
}