Patients with Sjögren-Larsson syndrome lack macular pigment

Abstract

Purpose: Sjögren-Larsson syndrome (SLS), an autosomal recessive hereditary disorder with congenital ichthyosis, spastic diplegia or tetraplegia, and mental retardation, reveals a characteristic macular dystrophy with intraretinal crystals and foveal pseudocysts. Ophthalmic symptoms in SLS are reduced visual acuity and photophobia. This article reports the deficiency of macular pigment as a novel finding in this peculiar, congenital maculopathy.

Design: Cross-sectional, observational case study.

Participants: Patients with clinically and genetically proven SLS.

Methods: Besides general ophthalmologic examination, 2 different methods were used, fundus autofluorescence (FAF) and fundus reflectometry with the macular pigment reflectometer (MPR), for measuring macular pigment (MP).

Main outcome measures: Distribution profiles and quantity of MP in eyes of SLS patients.

Results: Twenty-eight eyes of 14 patients were included. The technique to measure MP depended on the ability of the mentally handicapped patients to cooperate. Fundus autofluorescence images providing qualitative estimates were obtained from 9 eyes of 5 patients, and MPR measures providing quantitative estimates were obtained from 19 eyes of 10 patients. Fundus autofluorescence images of SLS patients lacked the typical attenuation of macular FAF signal expected in normal eyes. Mean foveal MP levels measured by MPR showed significantly lower values in SLS patients (0.10+/-0.07) than in healthy individuals (0.69+/-0.17; P<0.001, Student t test).

Conclusions: The group of SLS patients studied here had significantly reduced levels of foveal MP. The crystalline macular dystrophy in SLS seems to be the first known disease with a genetically caused deficiency of MP.