Case Report: Occult Macular Dystrophy

Abstract

SIGNIFICANCE:This case report discusses a case of suspected occult macular dystrophy, which is an underrecognized but not rare subtype of cone dystrophy. Increasing clinician recognition of occult macular dystrophy will lead to increased accurate diagnosis of affected patients. PURPOSE:A clinical presentation and diagnosis of a case of suspected occult macular dystrophy, as well as background information and management, are reported.CASE REPORT: A 44-year-old White man reported long-standing decreased vision and photophobia in both eyes. Examination revealed a bilateral reduction in best-corrected visual acuity, abnormal color vision, central visual field defects, and subtle disruption of subfoveal photoreceptor integrity on optical coherence tomography with a normal fundus appearance. The multifocal electroretinogram showed decreased perifoveal responses, whereas both the photopic and scotopic full-field electroretinograms were normal. This distinctive electroretinogram response pattern was critical in the diagnosis of occult macular dystrophy.CONCLUSIONS: Reduced visual acuity with a normal clinical examination result is commonly encountered in patients with occult macular dystrophy. Therefore, clinicians must be aware of occult macular dystrophy and order appropriate testing to accurately identify cases of occult macular dystrophy. Without thorough evaluation, patients may be easily misdiagnosed with other etiologies of vision loss.

New recessive compound heterozygous variants of RP1L1 in RP1L1 maculopathy

“…In addition, c.4717_4718del variant has not been reported previously, which forms a frameshift stop codon. It is reported that either variant in RP1L1 has not been reported in some patients with maculopathy, suggesting that the disease may be caused by both variants [9] . RP1L1 variants can also be found in RP, OMD or maculopathy [6] .…”

“…Pathologic variants in RP1L1 can lead to occult macular dystrophy (OMD), which is a hereditary macular dystrophy characterized by progressive visual loss but without apparent fundus abnormality [8] . The disease was firstly reported in 1989 and regarded as autosomal dominant inheritance while some sporadic cases have been reported since then [9][10] . In 2010, RP1L1 was identified as the pathogenic gene of OMD [11] .…”