Monitoring progression of retinitis pigmentosa: current recommendations and recent advances

ABSTRACT

Introduction: Retinitis pigmentosa (RP) is the most common form of inherited retinal degenerations with an estimated prevalence of 1 in 4,000 and more than 1 million individuals affected worldwide. With the introduction of the first retinal gene therapy in 2017, the importance of understanding the mechanisms of retinal degeneration and its natural progression has shifted from being of academic interest to being of pivotal for the development of new therapies.

Areas covered: This review covers standard and innovative diagnostic techniques and complementary examinations needed for the evaluation and treatment of RP. It includes chapters on the assessment of visual function, retinal morphology, and genotyping.

Expert opinion: Monitoring the progression of RP can best be achieved by combining assessments of both visual function and morphology. Visual acuity testing using ETDRS charts should be complemented by low-luminance visual acuity and color vision tests. Assessment of the visual field can also be useful in less advanced cases. In those with central RP involvement measuring retinal sensitivity using microperimetry is recommended. Retinal morphology is best assessed by OCT and autofluorescence. Genetic testing is pivotal as it contributes to the pathophysiological understanding and can guide clinical management as well as identify individuals that could benefit from retinal gene therapy.

KEYWORDS:

• Autofluorescence
• ETDRS letters
• genotyping
• inherited retinal degeneration
• IRD
• microperimetry
• optical coherence tomography
• OCT
• retinitis pigmentosa
• RP

Article highlights

• Comprehensive discussion of standard and innovative techniques to diagnose and monitor RP

• Article discusses both functional and morphological parameters

• Guideline for the retinal specialist interested in the clinical management of RP patients

• Overview of outcome measures pertinent to the design of clinical trials in retinal degenerative diseases

This box summarizes key points contained in the article.

Acknowledgments

Authors thank Jasleen K Jolly, MSc for providing the ERG figure.

Declaration of Interest

M Menghini has received financial support from Retina Suisse, OPOS Foundation and Schweizerischer Fond zur Verhütung und Bekämpfung von Blindheit. J Cehajic-Kapetanovic has received financial support from NIHR Clinical Research Fellowship, UK and Global Ophthalmology Awards Programme Fellowship, Bayer Switzerland and NIHR Oxford Biomedical Research Centre and RE Maclaren is listed as an inventor on a number of patents on retinal gene therapy owned by the University of Oxford. None of these patents has any direct relevance to the outcome measures discussed in this review. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This paper was funded by Retina Suisse, OPOS Foundation, Schweizerischer Fond zur Verhütung und Bekämpfung von Blindheit, NIHR Clinical Research Fellowship, UK and Global Ophthalmology Awards Programme Fellowship, Bayer Switzerland and NIHR Oxford Biomedical Research Centre.