The venules appear strikingly less involved (red arrow)įollow-up OCT images after two weeks also showed the retinal precipitates that appear to have migrated into more subretinal or pre–retinal pigment epithelium (RPE) locations. OCTA imaging showing intra-arteriolar location of crystals, distributed along the vessel wall (yellow arrow). Foveal section showed deposits at the level of the inner plexiform layer corresponding to the inner retinal arteriolar plexus. As fundus fluorescein angiography (FFA) was contraindicated by the nephrologist, we proceeded with optical coherence tomography (OCT) and OCT-Angiography (OCTA), which showed outer retinal and sub-retinal crystalline deposits in the macula with arteriolar wall studded with crystalline deposits which render the vessel wall hyperreflective and well delineated against a homogenous retinal reflectivity. The crystals appeared more numerous and clearly delineated in the red-free photo compared to autofluorescence image.
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The veins appeared normal without any crystalline deposits. There was a striking granular appearance delineating the arterial tree. Considering differential diagnoses of hypertensive retinopathy, OIS, combined retinal vascular occlusion or non-arteritic anterior ischemic optic neuropathy, the patient was referred back to the nephrologist for urgent control of hypertension and elevated serum oxalate levels.įundus photography confirmed ophthalmoscopic findings with whitish crystalline deposits diffusely deposited in the retinal layers bilaterally. On fundus examination, both eyes showed clear media with pale disc with multiple cotton wool spots with superficial and deep retinal hemorrhages and whitish crystalline deposits and inferior exudative retinal detachment. Anterior segment findings were within normal limits. On ocular examination, her best corrected visual acuity (BCVA) was 5/60 in both eyes. There was a bruit in the left forearm with an arterio-venous (AV) fistula for hemodialysis. Nail beds and tarsal conjunctiva showed gross pallor. The systemic evaluation revealed a blood pressure (BP) of 208/112 mmHg. She was referred by the nephrologist for evaluation of her ocular symptoms. Further evaluation had revealed primary oxaluria with AGXT gene mutation.
![optical coherence tomography angiography optical coherence tomography angiography](https://i.ytimg.com/vi/BxRAAVr7oA8/maxresdefault.jpg)
She had a history of recurrent renal calculi requiring lithotripsy, hypertension, ureteric stenting and chronic renal failure necessitating thrice weekly hemodialysis. We present a case of primary hyperoxaluria with an identified alanine–glyoxylate aminotransferase ( AGXT) gene mutation which resulted in nephrocalcinosis and retinal oxalosis.Ī 56-year-old lady presented with sudden diminution of vision for about two weeks.
![optical coherence tomography angiography optical coherence tomography angiography](https://www.dovepress.com/cr_data/article_fulltext/s148000/148897/img/OPTH-148897-F02.jpg)
Primary hyperoxalurias are rare autosomal recessive inborn errors of glyoxylate metabolism that can lead to oxalate accumulation, recurrent nephrocalcinosis and retinal oxalosis. Exogenously, crystalline deposits may be precipitated due to excessive dietary intake of oxalate rich foods, usually leafy vegetables or high dose vitamin C in patients with renal compromise. Systemic oxalosis can result from endogenous sources due to break down of ascorbic acid and amino acids. Oxalate is a byproduct of normal metabolism and is excreted from the body by the kidneys through urine.