neuroretinitis ( nr ) is considered to be an inflammatory condition which is characterized by optic disc edema and , as a result , formation of a macular star figure . nr is an atypical presentation of toxoplasmosis infection , and such cases are quite rare . a 13-year - old girl presented with painless subacute visual loss in her right eye for a week at khatam - al - anbia eye hospital in mashhad , iran . although toxoplasmosis nr is rare , it should be considered in the differential diagnoses of nr . neuroretinitis ( nr ) is considered an inflammatory condition which is characterized by optic disc edema and , as a result , formation of a macular star figure ( 1 ) . this disorder is possibly caused by an infectious process affecting the disc ; in other instances , a post - viral or autoimmune mechanism seems to be a more probable cause ( 1 ) . furthermore , some instances of nr have been reported to be accompanied by a wide spectrum of infectious pathogens ( 1 ) . the most common case reported so far is the result of cat scratch disease ( csd ) , accounting for two - thirds of cases in one study ( 2 ) . however , there are other infectious etiologies of neuroretinitis , including rubeola , toxoplasmosis , herpes simplex , varicella , tuberculosis , lyme disease , leptospirosis , syphilis , various fungi , and multiple viral illnesses ( 1 ) . additionally , sporadic cases of nr may occur owing to noninfectious forms of uveitis , such as sarcoidosis and periarteritis nodosa ( 3 , 4 ) . optic disc edema with a macular star may also occur as a result of other factors such as diabetic papillopathy , hypertensive neuropathy , and anterior ischemic optic neuropathy papilledema ( 1 ) . to determine the relevant history of patients with nr , the practitioner needs to concentrate on plausible risk factors for specific infectious parameters , such as travelling to areas where lyme disease or tuberculosis ( for example ) are endemic , exposure to waste material ( e.g. , leptospirosis ) , animal exposure ( especially cats ) , and sexual contact that may have resulted in the contraction of syphilis . the clinician should investigate patients for systemic symptoms such as lymphadenopathy , headache , fever , and skin rash . laboratory tests ought to be customized for the individuals on the basis of information from both their reported history and the examination . serologic tests for most cases may include the fluorescent treponemal antibody absorption test ( fta - abs ) , cat scratch titers ( bartonella species ) , and a tuberculosis skin test ( purified protein derivative , or ppd ) ( 1 ) . in this study , we present a case of unilateral neuroretinitis in which the serology result was apparently negative for acute infection of toxoplasmosis ( negative igm titer for toxoplasmosis , but positive for igg ) . based on anti - toxoplasma treatment that was administered for the positive igg levels , the condition responded well with near optimal visual recovery . a 13-year - old girl was referred to the ophthalmic emergency department of khatam - al - anbia eye hospital , mashhad , iran , which is affiliated with mashhad university of medical sciences ( mums ) , in may of 2013 with painless subacute visual loss in her right eye for one week . she denied any focal neurologic condition , pain on eye movement or ophthalmodynia , or any other systemic symptom . she also stated that she had not engaged in outdoor camping or any other related activity . furthermore , she had no remarkable past medical and ophthalmologic history , and she had no contact or proximity to pets , especially cats . upon examination , the best corrected visual acuity ( bcva ) was 20/250 in the right eye and 20/20 in the left eye . moreover , the patient had a grade 2 + relative afferent papillary defect ( rapd ) in the right eye . an examination of the anterior segment demonstrated 2 + cells in the anterior chamber ( a / c ) and 1 + vitreous reaction with normal intraocular pressure ( iop ) in the right eye . the investigation of the right fundus revealed optic disc swelling , macular star lipid ( hard exudates ) deposition , and peripapillary vascular sheathing ( figure 1 ) . many tests were performed for the patient , including the erythrocyte sedimentation rate ( esr ) , complete blood count differential ( cbc diff . ) , c - reactive protein ( crp ) , toxoplasmosis serology , purified protein derivative ( ppd ) , angiotensin converting enzyme ( ace ) , fta - abs , brain and orbital mri , chest x - ray , and infectious and rheumatologic consultation . bartonella henselae serology was not available in our ophthalmology center , nor in any other nearby neighborhood . based on our clinical results , neuroretinitis etiology revealed csd as the most common infectious etiology , along with the negative systemic and ocular history , and empirical treatment commenced including azithromycin 500 mg daily , trimethoprim / sulfamethoxazole , and the application of a topical steroid . after 72 hours , all the above - mentioned laboratory indices returned to the normal level , except for the toxoplasmosis serology . furthermore , the serologic test for toxoplasmosis was negative for igm antibody whereas the igg antibody titer was > 100 iu / ml . relying on the positive igg toxoplasmosis serology and the absence of any response to initial treatment , we embarked on shifting to classic anti - toxoplasmosis treatment , i.e. , sulfadiazine 500 mg qid ( four times a day ) , pyrimethamine 50 mg / day , and folinic acid . after 72 hours had passed , prednisolone 1mg / kg / day was added and thereafter tapered during the treatment . the disc edema diminished over the course of a week . also , visual acuity gradually improved and the a / c inflammatory reaction faded away . after the decrease in disc swelling , a very small hyperpigmented focus appeared in the juxtapapillary position . gradually , over the next two months , the patient s visual acuity improved to 9/10 and the optic disc swelling and macular exudates resolved ( figure 2 ) . the clinical syndrome of idiopathic stellate maculopathy accompanied by optic nerve edema was first identified by leber in 1916 ( 5 ) . later on , this syndrome was renamed as leber s stellate neuroretinitis . as is now known , the most common form of infectious nr results from csd ( 1 ) . the engagement of the optic nerve suggests the need for urgent intervention . in spite of the lack of evidence either for animal exposure or any other systemic condition for this case , empirical csd treatment was instituted as lab tests were pending and given that cat scratch serology was not accessible . toxoplasmosic retinochoroiditis is rendered as one of the most frequent causes of posterior uveitis , specifically in young patients ( 6 ) . however , toxoplasmic optic neuropathy is an infrequent condition and is often characterized by subacute visual loss and optic nerve swelling , and is sometimes associated with a macular star ( neuroretinitis ) ( 7 ) . the engagement of the optic nerve most commonly encountered in ocular toxoplasmosis is optic nerve edema with a simultaneous distant active lesion . other types of optic nerve involvement include pure papillitis presented as optic disc swelling , associated with peripapillary vascular sheathing close to the healed lesion , and neuroretinitis , i.e. , optic disc swelling with macular hard exudate deposition . additionally , monocular involvement has been observed in most cases with favorable visual prognosis ( 8) . considering the positive toxoplasmosis serology in this patient , toxoplasmosis neuroretinitis was suspected , hence prompting the specified treatment . this case disclosed optic disc involvement and neuroretinitis owing to juxtapapillary chorioretinitis reactivation . in some cases , the juxtapapillary chorioretinal scar can not be found in the acute stage of disease due to disc and peripapillary edema . although toxoplasmosis neuroretinitis is rare , it should be still considered in any suspected case of neuroretinitis . this case re - emphasizes the necessity of considering toxoplasmosis in the differential diagnosis of neuroretinitis . awareness of this potential cause and prompt treatment after positive testing may therefore result in a good visual outcome .
introductionneuroretinitis ( nr ) is considered to be an inflammatory condition which is characterized by optic disc edema and , as a result , formation of a macular star figure . 
 nr is an atypical presentation of toxoplasmosis infection , and such cases are quite rare.case presentationa 13-year - old girl presented with painless subacute visual loss in her right eye for a week at khatam - al - anbia eye hospital in mashhad , iran . 
 following comprehensive evaluation , a diagnosis of toxoplasmic nr was made . 
 the nr favorably responded to classic anti - toxoplasmosis treatment . 
 a juxtapapillary retinochoroidal scar appeared after disc swelling resolution.conclusionsalthough toxoplasmosis nr is rare , it should be considered in the differential diagnoses of nr .