Initial Evidences of Salt and Pepper Retinal Lesions (SPRL) in Patients with Intestinal Protozoan Infections in Iran

Background: It is made clear that salt and pepper retinal lesion (SPRL) has subsequently associated with the infection with Giardia lamblia (G. lamblia). However, little is known regarding the prevalence of SPRL among patients suffered from parasitic infections in the world. Objective: This study aimed to determine the prevalence of SPRL among patients with intestinal protozoan infections, for the first time, in Sari, northern Iran. Methods: In this case-control study, a total of 150 subjects participated: 75 were in the patients group diagnosed to have an intestinal parasite and 75 in the control group without any intestinal infection. Fecal samples were obtained from all participants and examined with wet mount and formalin-ether methods. The retina of both groups was examined by an ophthalmologist. Results: Overall, salt and pepper retinal changes were diagnosed in 12 (16 %) patients with at least one parasitic infection (7 females and 5 males). G. lamblia was diagnosed in 6 subjects (50%), Blastocystis hominis in 5 (41.6%), and Entamoeba coli in 1 (8.3 %). Most of the patients (58.3%) had a mild infection. Bilateral retinal involvement was observed in 75% of the patients. Furthermore, macula involvement was observed in 91.7 % with SPRL. Conclusion: Our findings indicated the relatively high prevalence of SPRL in subjects with giardiasis and blastocystosis. It can be concluded that not only G. lamblia but also B. hominis can cause SPRL in Sari, Iran. Further studies are needed to find other etiologic parasites able to cause retinal damages.