a 32-year - old woman presented to us with the chief complaint of difficulty in night vision in her right eye . she had no history of any systemic disease , malignancy , chronic drug intake , or any inflammatory eye disease in the past . the best corrected visual acuity was 20/50 in the right eye and 20/30 in the left eye . the intraocular pressure was 10 mmhg in the right eye and 20 mmhg in the left eye . fundus examination showed waxy pallor of the disc , arteriolar attenuation , bony spicule pigmentation , diagnostic of rp , in the right eye [ fig . the left eye showed a normal pink - colored disc and no attenuation of arterioles or bony spicules . optical coherence tomography of the macula showed loss of the ellipsoid zone and external limiting membrane with retinal thinning [ fig . 2c ] . electroretinogram ( erg ) of the right eye showed nonrecordable scotopic and photopic responses [ fig . 3a ] and a multifocal erg showed nonrecordable foveal , parafoveal , and perifoveal ring responses [ fig . 4a ] . however , the left eye showed hypoautofluorescence only along the vessels [ fig . 3a ] and normal foveal , parafoveal , and perifoveal ring responses on multifocal erg [ fig . fundus photograph of the right eye showing waxy pallor of the disc , attenuated arterioles , and bony spicule pigmentation characteristic of retinitis pigmentosa ( a ) . the left eye shows normal disc , normal caliber of arterioles , mild atrophy of the retinal pigment epithelium along the blood vessels , and a few perivascular bony spicule pigments , suggestive of pigmented paravenous retinochoroidal atrophy ( b ) fundus autofluorescence images of right and left eye . the right eye shows generalized hypoautofluorescence in the peripheral retina and a hyperautofluorescent ring with central hypoautofluorescence at the posterior pole ( a ) . optical coherence tomography of the right eye showing loss of the ellipsoid zone and external limiting membrane with thinning of the retina ( c ) , optical coherence tomography of the left eye showing intact ellipsoid zone and external limiting membrane ( d ) electroretinogram of the right eye showing nonrecordable scotopic and photopic responses and left eye showing normal scotopic and photopic responses ( a ) . multifocal electroretinogram of the right eye with nonrecordable foveal , parafoveal , and perifoveal ring responses ( b ) and left eye showing normal foveal , parafoveal , and perifoveal ring responses in the left eye ( c ) peripheral constriction of visual fields in the right eye ( a ) and normal visual fields in the left eye ( b ) unilateral rp is known to occur where the other eye is mostly seen to be normal . it was earlier thought to be postinflammatory , but many reports of familial cases make hereditary nature of this condition quite apparent . interestingly , our patient has both , rp in one eye and pprca in the other eye . despite a thorough literature search using pubmed , ovid medline , embase , and google scholar the occurrence of unilateral rp in the mother and bilateral pprca in two of her children has been reported , where all these patients showed no changes in ocular findings for 21 years . various mutations of the crb1 gene have been implicated in the etiology of pprca and also of rp . the pprca phenotype has been found to be associated with a val162met mutation and three novel mutations of crb1 gene have been described in rp . therefore , we postulate that our patient may have a hitherto unknown novel mutation of the crb1 gene , leading to a peculiar phenotypic expression of rp in one eye and pprca in the other . we could not confirm the etiology as our patient could not undergo genetic studies . a long - term follow - up would reveal how the left eye condition progresses , particularly whether rp like degeneration develops in that eye . however , erg is seen to be abnormal in earliest stages of rp where the retina still appears normal . in our patient , the presence of a normal response on erg is sufficient to confirm the fact that the left eye is unlikely to develop rp . in summary , we present an interesting case of two different phenotypes in the same patient that of rp in one eye and pprca in the other eye . to the best of our knowledge ,
we report a unique case of a patient with retinitis pigmentosa ( rp ) phenotype in one eye and pigmented paravenous retinochoroidal atrophy ( pprca ) phenotype in the other eye . 
 we describe in detail the symptoms , clinical findings , and investigations done for a 32-year - old indian woman . 
 this patient had phenotypical picture resembling typical rp in the right eye , with characteristic symptoms of night blindness and constricted field of vision and a nonrecordable electroretinogram ( erg ) . 
 the left eye of the same patient revealed typical pprca phenotype , with no night blindness , normal field , and normal erg . 
 rp and pprca phenotypes are part of the same spectrum of genetic disorder 
 . however , it is rare to see them coexist in the same patient .