June 2021
Volume 62, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2021
Usability of AdaptDx for Dark Adaptation Testing in Choroideremia
Author Affiliations & Notes
  • Hend M Ahmed
    Institute of Ophthalmology, University College London, London, United Kingdom
    Pathology, Mansoura University Faculty of Medicine, Mansoura, Egypt
  • Jasleen K Jolly
    Oxford University Eye Hospital, United Kingdom
  • Lyndon Da Cruz
    Moorfields Eye Hospital, United Kingdom
  • Adam M Dubis
    Institute of Ophthalmology, University College London, London, United Kingdom
    Moorfields Eye Hospital, United Kingdom
  • Robert E. MacLaren
    Oxford University Eye Hospital, United Kingdom
    Moorfields Eye Hospital, United Kingdom
  • Footnotes
    Commercial Relationships   Hend Ahmed, None; Jasleen Jolly, None; Lyndon Da Cruz, None; Adam Dubis, None; Robert MacLaren, Biogen (C)
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science June 2021, Vol.62, 2294. doi:
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      Hend M Ahmed, Jasleen K Jolly, Lyndon Da Cruz, Adam M Dubis, Robert E. MacLaren; Usability of AdaptDx for Dark Adaptation Testing in Choroideremia. Invest. Ophthalmol. Vis. Sci. 2021;62(8):2294.

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

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Purpose : Choroideremia is an X-linked retinal degeneration which causes a circumferentially constricting degeneration of the retinal pigment epithelium and choroid, leading to rod function loss. Current dark adaptation protocols test the full field sensitivity and seek the absolute dark-adapted threshold. Alternatively, single point testing and sub-absolute threshold endpoints may provide the opportunity for quicker, more reliable testing in this disease.

Methods : Choroideremia patients underwent dark adaptation testing using the AdaptDx (Maculogix, Hummelstown, PA, USA) dark adaptometer and autofluorescence imaging. Following 80% rod bleaching, testing was performed at 9-degree superior to fixation. Rod recovery time was defined as the time needed to achieve a sensitivity improvement of 3 AU. The sensitivity at 18min was also recorded. Autofluorescence images were reviewed to assess whether the testing location lay within the preserved retina.

Results : Fifty-six eyes from 28 patients were included in this analysis. Twenty-one eyes had a detectable rod recovery time (mean±SD, 15.0 ± 4.3 minutes), with 3 of them <10 min which was deemed normal. Three patients had a detectable recovery in only 1 eye. At 18 minutes, the average threshold for all eyes was 2.30 ± 0.82. A strong correlation in 18-minute sensitivity was observed between right and left eyes (R2 = 0.70). Eyes with detectable rod recovery had significantly higher sensitivity (mean±SD, 3.12 ± 0.56) compared with eyes with undetectable recovery (1.81 ± 0.25, p <0.001). Thirty-two eyes had residual retina at the targeted region. The average threshold at 18 minutes for these eyes was 2.62 ± 0.77 dB. Of these, only 15 eyes had a detectable rod recovery. Meanwhile, 6 eyes with no remaining retina at the targeted point had a detectable, yet prolonged, rod recovery. Interestingly, no significant association was observed between the undetectable rod recovery and presence/absence of remaining retina the testing location (p = 0.09).

Conclusions : The dark adaptation testing maybe useful for assessment of choroideremia. AdaptDX testing provided several key findings. The mean threshold at 18 min was greater for the eyes with detectable rod recovery time. However, the lack of relationship between presence of residual retina and testing threshold suggest eye movement may have played a role and would need to be controlled in future use.

This is a 2021 ARVO Annual Meeting abstract.


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