Alport syndrome presenting as Bilateral spontaneous anterior lens capsule rupture: case report

Dr Dian Petrus van der Westhuizen from Kimberley Hospital Complex, South Africa and colleagues have reported a rare case of Alport syndrome whose first presenting feature was bilateral spontaneous anterior lens capsule rupture.

The case report has been published in the American Journal of Ophthalmology Case Reports.

An eight-year-old male child presented to the hospital with complaints of decrease in vision in the left eye for the past 3 months. On examination, the best corrected visual acuity in the right eye was 20/20 but the left eye could only distinguish hand movements. There was an obvious leucocoria in the left eye.

Slit lamp evaluation of the left eye revealed ruptured anterior lens capsule with lens matter in the anterior chamber. There was an intumescent cataract with IOP of 38mm Hg. Fundus examination was not possible due to the cataract.

The right eye demonstrated anterior lenticonus with a central tear in the anterior capsule. The lens matter was contained inside the capsule but there early anterior polar cataract. Fundus examination in the right eye was normal.

Phacoemulsification cataract surgery with insertion of intraocular lens was performed in the left eye following which BCVA improved to 20/20.

Six weeks later, the patient presented with complaints of decrease in vision in the right eye. The uncorrected visual acuity in the right eye was 20/60 with BCVA of 20/30. Examination revealed supero-nasal extension of the anterior capsular defect with bulging and opacification of the underlying lens cortex. Phacoemulsification cataract surgery with insertion of intraocular lens was performed in the right eye. Post-operatively the BCVA improved to 20/20.

To ascertain the etiology of this uncommon presentation, further investigations were advised. The patient's mother described a family history of an unknown kidney disease in three of her maternal male cousins, all of whom had died before their third decade. Audiological testing, renal biopsy and genetic testing were advised keeping in mind the possibility of Alport syndrome since the patient had presented with anterior lenticonus.

Audiological testing demonstrated bilateral moderate-to-severe high frequency sensorineural hearing loss. Urinalysis revealed proteinuria and microscopic haematuria with red blood cell casts. Electron microscopic analysis of a renal biopsy showed the characteristic basement membrane changes associated with Alport syndrome. Genetic analysis of the patient and his mother established the diagnosis of X-linked Alport Syndrome. The patient was referred to the paediatric and nephrology departments for further management.

Alport syndrome (AS) is a rare basement membrane disorder characterized by haematuria with progressive renal failure, sensorineural deafness and ocular abnormalities. The typical ocular manifestations of AS are anterior lenticonus, peripheral fleck retinopathy, and temporal macular thinning. Recurrent corneal erosions, posterior polymorphous corneal dystrophy, posterior lenticonus and keratoconus are also less common associations. Bilateral spontaneous rupture of the anterior lens capsule in Alport syndrome has not been reported in literature so far, according to the authors.

It is roughly estimated that 40% of children with X-linked AS may be diagnosed based on ocular features alone. "Since the long-term systemic implication of the disease are grave, AS should be considered in any patient presenting with anterior lenticonus or rupture of the anterior lens capsule, even if other features of the syndrome are not present." conclude the authors.

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https://www.sciencedirect.com/science/article/pii/S2451993620302115