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What do patients with glaucoma see: a novel iPad app to improve glaucoma patient awareness of visual field loss
  1. Meghal Gagrani1,
  2. Jideofor Ndulue1,
  3. David Anderson1,
  4. Sachin Kedar2,
  5. Vikas Gulati1,
  6. John Shepherd1,
  7. Robin High3,
  8. Lynette Smith3,
  9. Zachary Fowler4,
  10. Deepak Khazanchi4,
  11. Mark Nawrot5,
  12. Deepta Ghate1
  1. 1 Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska, USA
  2. 2 Ophthalmology and Visual Sciences, Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, Nebraska, USA
  3. 3 College of Public Health, University of Nebraska Medical Center, Omaha, Nebraska, USA
  4. 4 College of Information Science and Technology, University of Nebraska at Omaha, Omaha, Nebraska, USA
  5. 5 Department of Psychology, North Dakota State University, Fargo, North Dakota, USA
  1. Correspondence to Deepta Ghate, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE 68105, USA; dghate{at}unmc.edu

Abstract

Purpose Glaucoma patients with peripheral vision loss have in the past subjectively described their field loss as ‘blurred’ or ‘no vision compromise’. We developed an iPad app for patients to self-characterise perception within areas of glaucomatous visual field loss.

Methods Twelve glaucoma patients with visual acuity ≥20/40 in each eye, stable and reliable Humphrey Visual Field (HVF) over 2 years were enrolled. An iPad app (held at 33 cm) allowed subjects to modify ‘blur’ or ‘dimness’ to match their perception of a 2×2 m wall-mounted poster at 1 m distance. Subjects fixated at the centre of the poster (spanning 45° of field from centre). The output was degree of blur/dim: normal, mild and severe noted on the iPad image at the 54 retinal loci tested by the HVF 24-2 and was compared to threshold sensitivity values at these loci. Monocular (Right eye (OD), left eye (OS)) HVF responses were used to calculate an integrated binocular (OU) visual field index (VFI). All three data sets were analysed separately.

Results 36 HVF and iPad responses from 12 subjects (mean age 71±8.2y) were analysed. The mean VFI was 77% OD, 76% OS, 83% OU. The most common iPad response reported was normal followed by blur. No subject reported dim response. The mean HVF sensitivity threshold was significantly associated with the iPad response at the corresponding retinal loci (For OD, OS and OU, respectively (dB): normal: 23, 25, 27; mild blur: 18, 16, 22; severe blur: 9, 9, 11). On receiver operative characteristic (ROC) curve analysis, the HVF retinal sensitivity cut-off at which subjects reported blur was 23.4 OD, 23 OS and 23.3 OU (dB).

Conclusions Glaucoma subjects self-pictorialised their field defects as blur; never dim or black. Our innovation allows translation of HVF data to quantitatively characterise visual perception in patients with glaucomatous field defects.

  • Glaucoma
  • Visual perception
  • Field of vision

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Footnotes

  • Contributors DG, SK, DA, VG, JS, MN conceived of the study. DG, DA, ZF, DK initiated the study design and JK, MG helped with implementation. The app was developed with the help of DK and ZF. LS and RH provided statistical expertise and conducted the primary statistical analysis. MG, DG wrote the manuscript. All authors contributed to refinement of the study protocol and approved the final manuscript.

  • Funding National Institute of General Medical Sciences, U54 GM115458, IDeA CTR, Scholars grant, Department of Ophthalmology Pilot Grant, University of Nebraska Medical Center, NIH K23 EY02326.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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