The aim of this 4-Year study was to analyze the population referred to our laboratory for the visual follow-up of hydroxychloroquine or chloroquine treatment.
We received 925 patients: 78% female, 22% male. For each patient, a 13-item criteria was filled out and regular exams were performed. The pathologies were divided in to 4 groups: rheumatoid polyarthritis (P), lupus (L), sarcoidosis (S), others (O).
The pathologies were distributed as follows: 48% "P", 29% "L", 3% "S", 1% "P + L", 19% "O". Of these patients, 19% had less than 1 Year of treatment, 73% 1-10 Years and 8% more than 10 Years. The screening exposed no retinal intoxications but 3% presented pre-clinical intoxication (PCI) and 80% were allowed to continue their treatment. The most important statistical results were: 1) a significant relation between the PCI and the duration of the treatment (p<0.001); 2) a non-significant relation between the PCI and the daily dose (p=0.417); and 3) a significant relation between PCI and the cumulative dose (p=0.003).
The results shows the advantage of the ERG in screening to prevent anti-malarial retinal toxicity. This study confirms that the cumulative dose seems to be more important than the daily dose, but we agree with the international consensus to respect a daily dose under 6.5 mg/kg/d. The results also demonstrated that, with this large and diversified population, there is a need for prospective and multi-centric studies. With the above results, international standards should be established in order to obtain the most efficient screening for each category of patient.