Ocular Toxoplasmosis Associated with Unilateral Pigmentary Retinopathy That May Mimic Retinitis Pigmentosa: Diagnostic Dilemmas

We report a unique case of coexisting pigmentary retinopathy and ocular toxoplasmosis in a young male patient. A 23-year-old man presented with sudden visual deterioration in the left eye (LE). The fundus findings revealed bone spicule-shaped pigment deposits, a slightly pale optic disc, arteriole constriction, cystoid macular edema with an epiretinal membrane, and two small inflammatory chorioretinal scars in the right eye, with a concentric narrowing of the visual field and a nonrecordable multifocal electroretinogram (ERG). An active inflammatory lesion at the border of a pre-existing chorioretinal scar in the macula was found in the LE, with a central scotoma in the visual field. Moreover, the patient tested positive for anti-Toxoplasma gondii immunoglobulin G antibodies and showed positive results in polymerase chain reaction testing of aqueous humor. Fluorescein angiography revealed hyperfluorescence in the early phase with fluorescein leakage. A multifocal ERG of the LE showed selective loss of responses from the central 10 degrees. Genetic testing revealed heterozygosity in the RP1 and CELSR1 genes. Our case illustrates challenges in the diagnosis of unilateral pigmentary retinopathy. Based on the typical toxoplasmic lesions in the LE and two scars likely caused by inflammation, our patient was diagnosed with pigmentary retinopathy probably related to toxoplasmosis. Genetic consultation did not confirm the diagnosis of retinitis pigmentosa, but more advanced tests might be needed to definitively exclude it.

Mitochondrial Diseases Associated with Retinopathy

Mitochondria are organelles that meet the energy needs of the cell through the electron transport chain and oxidative phosphorylation system. Its functions are regulated by double genomes, nuclear and mitochondrial DNA. Mutations that can occur in both genomes cause mitochondrial diseases, a group of clinically and genetically heterogeneous diseases. The entire ocular system, from the eyelids to the extraocular muscles, to the retina, such as the central nervous system, skeleton, and cardiac muscles, needs high oxidative phosphorylation. Common ophthalmic symptoms of mitochondrial dysfunction include optic atrophy, pigmentary retinopathy, cataracts, sudden vision loss, external ophthalmoplegia. Pigmentary retinopathy is the most common nonspecific retinal pathology and threatens vision. The emergence of the same mutation with different phenotypes in different individuals and tissues affects the clinical appearance of retinal pathologies. Different dystrophies can be observed, ranging from mild retinal pigment epithelial changes to salt pepper retinopathy, from circumferential perifoveal atrophy to reasonable pattern dystrophy. Diagnosis of all mitochondrial diseases requires detailed systemic screening. It is important to recognize and diagnose the ophthalmological signs of mitochondrial disorders as early as possible. Although treatments are mostly symptomatic, antioxidant treatments continue to be developed and gene therapy is promising for new cases.

Kearns Sayer Syndrome- A Case Report

Kearns–Sayre syndrome (KSS) is a rare mitochondrial disease was first described in 1958. The characteristic triad is age of onset less than 20 years, progressive external ophthalmoplegia, pigmentary retinopathy, The prevalence rate of KSS is nearly 1–3 per 100 000 individuals. Here, we report a rare case of a 11-year-old male with KSS.

Posterior microphthalmos with pigmentary retinopathy

We report a case of 19-year-old man with gradual diminution of vision in both eyes since childhood. His best-corrected visual acuity was 20/160, N16 in the right eye and 20/200, N16 in the left eye. Slit-lamp biomicroscopic examination revealed normal cornea, anterior segment, intraocular pressure and lens. Fundus of both eyes showed crowded optic disc with pigmentary changes. Ancillary tests were performed to aid in the diagnosis. A-scan ultrasound revealed short axial lengths with normal corneal diameter, anterior chamber depth and lens thickness. Optical coherence tomography of both eyes showed inner retinal layer folds. Electroretinogram of both eyes showed extinguished photopic as well as scoptopic responses. A diagnosis of posterior microphthalmos with pigmentary retinopathy was made. The patient was counselled regarding nature of the disease and the condition was managed with low vision aids.

Senior-Loken syndrome: A case report

Senior-Loken syndrome refers to a combination of nephronophthisis and retinal dystrophy. Nephronophthisis progresses to end-stage renal disease during the second decade. The retinal lesions vary from severe infantile onset retinal dystrophy to milder pigmentary retinopathy. There is a spectrum of associated features, including skeletal, dermatological, and cerebellar anomalies. Here, we report a case of first genetically proven Senior-Loken syndrome in India, who presented with growth failure, polyuria, polydipsia, nystagmus, and defective night vision.

Usher Deafblindnes

Pigmentary retinopathy refers to a group of inherited degenerative diseases of the retina, which primarily affects the photoreceptor cells in the retina. The association with congenital hearing loss defines Usher syndrome. Usher syndrome is a rare pathology of autosomal recessive transmission with a double sensory impairment (auditory and visual). We report the observation of a 12-year-old patient from a consanguineous marriage with congenital deafness, normal vestibular function and pigmentary retinopathy composing type 2 of Usher syndrome.