Clinical Manifestations of Ocular Toxoplasmosis at a Referral Center in Iraq

The mean


INTRODUCTION:
Toxoplasmosis is caused by the parasite Toxoplasma gondii, a single-cell obligate intracellular apicomplexan parasite. 1  Congenital infection is caused by trans-placental transmission of T gondii during pregnancy, while acquired infection may be caused by either one of the following: consumption of undercooked meat infected by tissue cysts, ingestion of water, fruit, or vegetables contaminated with oocytes, accidental contact with cat litter, feces, or soil containing oocytes, blood transfusion or organ transplantation. 4 Clinical manifestations of ocular toxoplasmosis: Symptoms: Ocular toxoplasmosis in young children may be asymptomatic while older children who are able to vocalize may present with reduced vision or ocular pain.5 Unilateral acute or sub-acute onset of floaters, blurring and photophobia are the main presenting features in adults. 2 The mean age for ABSTRACT: BACKGROUND: Ocular toxoplasmosis is an important cause of posterior uveitis worldwide including Iraq.

OBJECTIVE:
To study the clinical manifestations of ocular toxoplasmosis at a referral center in Iraq.

PATIENTS AND METHODS:
Nine months prospective case series study was performed in the outpatient clinic at Ibn Al Haetham teaching eye hospital in Baghdad, Iraq. The diagnosis was mainly clinical supported by serological tests.

CONCLUSION:
The commonest type of presentation of ocular toxoplasmosis seen in this study was the primary active retinitis, followed by recurrent disease. Poor visual outcome seen at the end of treatment course was mainly due to macular involvement. KEYWORDS: ocular toxoplasmosis, recurrent, primary active disease. This study is a descriptive prospective case series study. It was performed at the outpatient clinic at Ibn Al-Haetham teaching eye hospital after an ethical board approval has been obtained from the Iraqi board for medical specialization. The prospective clinical and laboratory medical data were collected for all patients seen in this study during June 2017 and February 2018 (9 months). An informed consent was obtained from all patients or their legal tutors. An ophthalmic history was taken at each visit along with complete ocular examination. The diagnosis of ocular toxoplasmosis was mainly clinical depending on the presence of characteristic lesions in the fundus supported by serological tests. Active ocular toxoplasmosis was defined by the presence of an active creamy-white focal fluffy necrotizing retinitis or retinochoroiditis. Primary ocular toxoplasmosis was defined as an active focal retinitis without associated pigmented retinochoroidal scars in either eye while the recurrent infection was defined as an active lesion in the presence of old pigmented retinochoroidal scars in either eye. An inactive lesion was defined as (in patients who have no known history of trauma , surgery, uveitis or laser therapy) an atrophic, well-defined retinal scar which often has a variable degree of pigmentation but a hypopigmented scar may also develop. Juxtapapillary lesions were defined as lesions that touched or covered the optic disc margin, & in this study,if a lesion touched the optic disc on the temporal side, it was classified as juxtapapillary,

OCULAR TOXOPLASMOSIS
rather than macular.26 peripheral lesions were defined as lesions located outside the temporal vascular arcades 2) Anterior chamber cells: was reported in 12 eyes (75%). 3) Keratic precipitates: They were smallmedium in size (granulomatous) and were reported in 3 patients (18.75%). The complications of ocular toxoplasmosis (seen in 8 eyes out of the 16 affected eyes with active disease): Twelve (75%) complications from ocular toxoplasmosis have been reported in 8 (50%) eyes and in some affected eyes there was more than one complication. They were included the following: High IOP (> 21mmHg) was seen in 3 eyes (18.75%), macular edema and optic disc swelling each one of them was reported in 2 eyes (12.5%), while each of (Choroidal neovascularization with retinal hemorrhage) and branch retinal vein occlusion was reported in 1 eye (6.25%). The reported complications after resolution were include: Cataract which was seen in 2 eyes (12.5%) and epiretinal membrane which was seen in 1 eye (6.25%). Patients with primary active retinitis (8 cases ''53.28%'' out of 15) were slightly morecommon than those patients with recurrent disease (in whom pre-existing retinochoroidal scars were discovered which indicates a prior subclinical disease) (7cases ''46.62%''). This rate of occurrence of primary lesions is higher than the rate reported by other studies 72%.7,32 In more than half of the cases (15 eyes ''55.5 %'' out of 27 eyes), the macula was involved and similar results were found in other studies. (27,29,31) Such higher incidence of macularin volvement seen in this study was an important cause of impact of ocular toxoplasmosis on vision. Vitritis associated with peripheral active lesions, epiretinal membrane & macular edema were an additional causes of poor vision seen in this study. Vitritis and anterior uveitis with different grades were a major additional clinical features seen in patients with active disease, while keratic precipitates were seen in three patients. Similar findings were also reported by Justine R. Smith et al. (12) High IOP, macular edema, optic disc swelling, BRVO, CNV, cataract and Epiretinal membrane were the main complications seen in 8 eyes (50%) with active disease, with an incidence rate of 75% (where more than one complication was reported in some affected eyes) & generally the rate of occurrence of individual complication was comparable to the results reported by other studies. (5,6)

CONCLUSION:
The commonest type of presentation of ocular toxoplasmosis seen in this study was the primary active retinitis, followed by recurrent disease. Poor visual outcome seen at the end of treatment course was mainly due to macular involvement.