UNVEILING THE RARITY: A CASE STUDY OF NIGRA CATARACT IN AN ELDERLY PATIENT

Cataract refers to the opacification of the lens located inside the eye, resulting in reduced vision at both distance and near that cannot be improved with optical correction. It is generally associated with aging but can also result from various factors such as diabetes, ocular trauma, and prolonged exposure to ultraviolet rays. Nigra cataract, also known as brown-black or pigmentary cataract, is a rare variant characterized by the presence of dark pigments in the lenses of older individuals.

The purpose of this study is to investigate the characteristics and clinical implications of nigra cataract in elderly patients.

Institution: Specialty Hospital, Ophthalmology Department, Rabat
Date of Study: May 9, 2024
Overview: This research focuses on the evaluation and surgical intervention of nigra cataracts, a rare variant, within the patient population of the ophthalmology department, aiming to improve diagnostic and treatment approaches.

We present a 65-year-old patient with no significant medical history, who consulted for profound visual acuity loss, with light perception in the left eye, progressing over several years. The visual acuity in the right eye was 7/10 with correction. Examination with a slit lamp revealed a dark brown lens with an inaccessible fundus. The patient was highly myopic, with an axial length of 28 mm.

The patient underwent extracapsular cataract surgery, which revealed the typical appearance of a black cataract known as nigra cataract, a rather rare form of cataract in older individuals.

Cataract is a prevalent eye condition marked by the clouding of the lens, which results in blurred and compromised vision. Timely diagnosis is essential for effective treatment, which may include surgical options. The underlying mechanisms of nigra cataract typically involve the buildup of dark pigments within the lens. The precise composition of these pigments is not well understood, but they could arise from several processes, including cellular component oxidation, oxidative stress, and ongoing inflammation. Additionally, genetic factors might contribute to an individual's susceptibility to this condition.

The assessment of the functional impact of a cataract is performed clinically. While decreased visual acuity is the primary symptom, each case presents specific clinical signs. A good understanding of the semiology and various clinical presentations of cataract is essential to determine the optimal timing for surgical intervention, in accordance with the standards of practice in ophthalmology.