Frequency and causes of visual impairment and blindness in patients with Xeroderma Pigmentosum in Brazil

Abstract

Purpose : Xeroderma Pigmentosum (XP) is a rare type of genodermatosis inherited as an autosomal recessive condition characterized as a hypersensitivity to sunlight resulting in exaggerated photoaging and photocarcinogenesis, with ocular manifestations described in 40-100% of patients. This study aimed to determine frequency and causes of visual impairment and blindness and to characterize ocular surface of XP patients in Brazil.

Methods : Patients were recruited over social media for a single day evaluation at Department of Ophthalmology - Federal University of Sao Paulo. The protocol included a complete ophthalmological exam with presenting (PVA) and best corrected (BCVA) visual acuities, automatized and subjective refractions, biomicroscopy, fundus evaluation plus specular microscopy, anterior and posterior photograph and optical coherence tomography, meibography (Keratograph; Oculus, Inc., Arlington, WA), and impression cytology. Visual impairment/blindness frequency was determined according to PVA in the better-seeing eye.

Results : Out of 32 participants (62.5% females) aged 25.53±15.70 years old, 10 (31.2%) had normal vision (PVA≥20/32), 11 (34.4%) moderate visual impairment (PVA<20/32 and ≥20/63), 6 (18.7%) visual impairment (PVA<20/63 and ≥20/200), and 5 (15.7%) severe blindness (PVA<20/400). The most frequent causes of visual impairment and blindness were leucoma due to tumor topic treatment (21.7%) and refractive errors (21.7%). Ocular surface squamous neoplasia (OSSN) was detected in 19 individuals (59.4%). 8 cases of papilloma (25.0%), 2 of melanoma (6.2%) and 1 of basal cell carcinoma (3.1%) were also identified. Meibography showed severe reduction of meibomian glands, grade 2 for superior and grade 3 for inferior eyelids. Impression cytology has confirmed the clinical OSSN diagnosis in all suspected cases and revealed subclinical microscopic disease in 5 patients. In general, 24 (75.0%) patients have developed any kind of ocular tumoral manifestation.

Conclusions : Most patients have shown ocular tumoral manifestations of XP leading to visual impairment and blindness in 1/4 of the cases. Posterior analysis of DNA samples might elucidate the roll of different genotypes on ophthalmic findings related to the disease.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.