Background Hydroxychloroquine is a disease modifying anti-rheumatic drug (DMARD) that has been used to treat a number of rheumatological conditions including rheumatoid arthritis, connective tissue diseases and increasingly, osteoarthritis. The main clinical concern with long term use is the rare complication of retinopathy. Significant retinopathy has only been reported in the literature in around 50 cases1, with over one million patients taking the drug. Nonetheless, it remains a concern. The signs of retinal toxicity are not specific to quinolone toxicity. Moreover, by the time even the earliest changes appear, there is some degree of irreversible damage2. Consideration was given to methods of detecting toxicity at the reversible stage. Static perimetry is time consuming and rarely available outside the hospital setting. However, the Amsler Grid is a simple and inexpensive visual test that can be self-administered by the patient.
To assess patient awareness of the ocular side effects of Hydroxychloroquine and compliance with the local recommendation for annual eye testing.
To assess patients' ability to understand and use the Amsler Grid as a screening tool.
Methods We produced our own Hydroxychloroquine information booklet, based on the Arthritis UK leaflet, with the inclusion of an Amsler Grid and instructions on how to use it. This was posted to 728 patients identified from our database as taking Hydroxychloroquine, with an accompanying questionnaire. Patients were asked the following questions:
How long have you been taking Hydroxychloroquine?
Are you aware that is recommended that you have an annual eye check-up whilst taking Hydroxychloroquine?
If so, have you been having a yearly eye check-up?
If not, please state a reason.
Did you find the new Hydroxychloroquine booklet: a) Easy to understand b) Contained: too much information/too little information/just right
Were you able to understand and use the Amsler Chart?
Results 334 of 728 patients returned a completed questionnaire. 35% of patients had been taking Hydroxychloroquine for over 5 years. 72% were aware that a yearly eye test was recommended and 75% were having one. Reasons cited for not having annual testing included financial difficulty, mobility problems and lack of motivation. 93% reported that the booklet was easy to understand and 95% felt it contained just the right amount of information. 92% of patients reported being able to understand and use the Amlser grid.
Conclusions The vast majority of patients found the new information booklet informative and user friendly. Our new booklet may help to increase awareness of ocular side effects, and to provide accessible screening for those who struggle to see an optician. Further work is needed to validate use of the Amsler Grid in rheumatology patients, but these results suggest its inclusion in a patient leaflet may be a useful adjunct to annual eye testing. If validated as a sensitive test for detecting ocular side effects of Hydroxycholoroquine during the reversible stage, the Amsler Grid could represent a superior, simpler and more cost-effective screen than yearly eye review.
Yam JCS, Kwok AKH. Ocular toxicity of hydroxychloroquine. Hong Kong Med J. 2006; 12:294-304.
The Royal College of Ophthalmologists - Hydroxychloroquine and Ocular Toxicity. Recommendations on Screening – October 2009
Disclosure of Interest None declared