A classical presentation of tint deficiency

An 8-year-old male, born to second-degree consanguineous parents, presented with gradual progressive diminution of vision and involuntary shaking of both eyes (OU) since birth. There were no associated systemic complaints, and he had an uneventful developmental history. His best corrected visual acuity was log of minimum angle of resolution (logMAR) 1 with mixed astigmatism (+5.00DS/-6.00 DC @ 180) in OU. On examination, he had generalized hypopigmentation of skin and hair and was orthophoric. The classical plethora of ocular findings seen in this child included hypopigmented eyelashes, iris hypochromia with transillumination defects [Fig. 1c], hypopigmented fundi, and congenital nystagmus, suggestive of oculocutaneous albinism (OCA). The ultrawide field fundus photographs depicted the transparent view of the arborizing choroidal vasculature beneath the hypopigmented retinal epithelium with grayish optic discs and an absent foveal reflex [Fig. 1a and b]. Ancillary testing like optical coherence tomography of the macula confirmed the hypoplastic foveae [Fig. 1d], which is a known association with this genetic disorder.[1] He was managed conservatively with spectacles, low vision aids for his scholastic activities, genetic counseling, and was explained regarding regular monitoring for refractive error and comprehensive ocular examination. Discussion OCA is an autosomal recessive inherited disorder of melanin biosynthesis and tyrosinase enzyme protein activity, which can present in different forms and varied severity ranging from partial to complete inability to synthesize melanin, causing severe visual impairment. TYR (OCA Type 1), OCA2 (OCA type 2, most common worldwide), TYRP1 (Rufous OCA type 3), and SLC45A2 (OCA type 4) are some of the involved genes.[2,3] Foveal hypoplasia and excessive crossing over of optic nerve fibers at the chiasma lead to nystagmus, strabismus, and color vision and stereovision abnormalities.[4] Diagnostic workup includes genetic testing, screening of family members, visual evoked potentials (VEP), and systemic evaluation for thrombopenia or abnormal neutrophils (as seen in Hermansky–Pudlak and Chediak–Higashi syndromes). Offering appropriate visual rehabilitation, refractive error correction, and genetic counseling are some of the key steps in management. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.Figure 1: (a and b) OU multicolor fundus photographs showing prominent choroidal vasculature visible through the depigmented retinal epithelium. (c) External photograph of the left eye under diffuse illumination of a slit-lamp biomicroscope revealing depigmented skin and eye lashes and hypochromic and translucent iris with enhanced fundus red glow and crystalline lens margin. (d) Spectral domain optical coherence tomography of the left eye macula with absence of normal foveal contour, suggestive of foveal hypoplasiaFinancial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.