Quantitative evaluation of visual function in patients with cornea verticillata associated with Fabry disease

Ocular manifestations of the genetic causes of focal and segmental glomerulosclerosis

Genetic forms of focal and segmental glomerulosclerosis (FSGS) often have extra-renal manifestations. This study examined FSGS-associated genes from the Genomics England Renal proteinuria panel for reported and likely ocular features. Thirty-two of the 55 genes (58%) were associated with ocular abnormalities in human disease, and a further 12 (22%) were expressed in the retina or had an eye phenotype in mouse models. The commonest genes affected in congenital nephrotic syndrome (NPHS1, NPHS2, WT1, LAMB2, PAX2 but not PLCE1) may have ocular manifestations . Many genes affected in childhood-adolescent onset FSGS (NPHS1, NPHS2, WT1, LAMB2, SMARCAL1, NUP107 but not TRPC6 or PLCE1) have ocular features. The commonest genes affected in adult-onset FSGS (COL4A3-COL4A5, GLA ) have ocular abnormalities but not the other frequently affected genes (ACTN4, CD2AP, INF2, TRPC6). Common ocular associations of genetic FSGS include cataract, myopia, strabismus, ptosis and retinal atrophy. Mitochondrial forms of FSGS (MELAS, MIDD, Kearn's Sayre disease) are associated with retinal atrophy and inherited retinal degeneration. Some genetic kidney diseases (CAKUT, ciliopathies, tubulopathies) that result in secondary forms of FSGS also have ocular features. Ocular manifestations suggest a genetic basis for FSGS, often help identify the affected gene, and prompt genetic testing. In general, ocular abnormalities require early evaluation by an ophthalmologist, and sometimes, monitoring or treatment to improve vision or prevent visual loss from complications. In addition, the patient should be examined for other syndromic features and first degree family members assessed.

Ophthalmic Manifestations in Fabry Disease: Updated Review

Fabry disease (FD) is an X-linked lysosomal storage disorder, causing Gb-3 (globotriaosylceramide) buildup in cellular lysosomes throughout the body, in particular in blood vessel walls, neuronal cells, and smooth muscle. The gradual accumulation of this glycosphingolipid in numerous eye tissues causes conjunctival vascular abnormalities, corneal epithelial opacities (cornea verticillata), lens opacities, and retinal vascular abnormalities. Although a severe vision impairment is rare, these abnormalities are diagnostic indicators and prognostics for severity. Cornea verticillata is the most common ophthalmic feature in both hemizygous men and heterozygous females. Vessel tortuosity has been linked to a faster disease progression and may be useful in predicting systemic involvement. New technologies such as optical coherence tomography angiography (OCTA) are useful for monitoring retinal microvasculature alterations in FD patients. Along with OCTA, corneal topographic analysis, confocal microscopy, and electro-functional examinations, contributed to the recognition of ocular abnormalities and have been correlated with systemic involvement. We offer an update regarding FD ocular manifestations, focusing on findings derived from the most recent imaging modalities, to optimize the management of this pathology.

Ocular findings and their correlation with disease severity in Fabry disease in South-East Anatolia

PURPOSE

To evaluate the ocular findings and the relationship between these findings and the disease severity of patients with Fabry disease (FD) in South-East Anatolia.

METHODS

We enrolled the 24 eyes of 24 patients with FD and the disease severity scores were obtained with FD severity scoring system (DS3). The relationship between the presence of any ocular findings and DS3 scores was evaluated.

RESULTS

The mean age of the patients was 35.2 ± 8.6 years. The mean DS3 score and α-galactosidase A enzyme activity of the patients was 7.04 ± 3.71 and 1.93 ± 0.84 μmol/l/h, respectively. Of the 24 patients, 20 (83.3%) had cornea verticillate (CV), 18 (75%) had tortuous conjunctival vessels, 15 (62.5%) had tortuous retinal vessels and 3 (12.5%) had lens opacities. The ocular vascular abnormalities were associated with disease severity (p < 0.05); however, the presence of CV did not affect the DS3 scores (p > 0.05).

CONCLUSIONS

According to our study, the patients with ocular vascular abnormalities associated with FD had more severe disease than those who did not have an abnormality. CV was the most common ocular finding in FD, but it has no association with disease severity.

Results of the screening program for Fabry disease in patients with cornea verticillata at the University Hospital of Navarre

INTRODUCTION

Cornea verticillata (CV) or vortex keratopathy is characterized by the presence of spiral-shaped deposits in the corneal epithelium. The most frequent causes are antimalarial drugs and amiodarone and, among systemic causes, Fabry disease (FD).

MATERIAL AND METHODS

A multidisciplinary, prospective, descriptive study was conducted in a tertiary reference center in Spain's Autonomous Community of Navarre after the implementation of a FD screening program for patients attended to in the Ophthalmology Department. The study analyzed those diagnosed with CV, who were subsequently referred to the rare disease clinic of the University Hospital of Navarre's Internal Medicine Department for an FD study.

RESULTS

Two women and four men with a mean age of 76.8 years were diagnosed with CV out of a total of 17,280 patients evaluated in outpatient consultations by three ophthalmology specialists during the period from April 2018 to April 2020. One patient died before performing the screening study and no patients were diagnosed with FD.

CONCLUSIONS

Despite the fact that the University Hospital of Navarre's FD screening program for patients with CV did not confirm any cases of FD, ophthalmology specialists should consider the possible diagnosis of FD in patients with CV in their routine consultations.

Contrast Sensitivity Changes after Phototherapeutic Keratectomy in Heterozygote Granular Corneal Dystrophy Type 2

Purpose: Contrast sensitivity, the ability to distinguish the relative difference in luminance of an object from its surrounding or adjacent objects, is a useful measure of visual function. In granular corneal dystrophy type 2 (GCD2), opacity of the corneal stroma causes deterioration in visual function. We compared the contrast sensitivity of GCD2 patients before and after phototherapeutic keratectomy (PTK) to evaluate the perioperative visual function in these patients.Methods: This study included 22 eyes of heterozygote GCD2 patients. The visual acuity and contrast sensitivity were measured before and after PTK. The contrast sensitivity was measured in mesopic and photopic background luminances, with glare (G) levels of 0-2 (G0, G1, and G2, respectively) and spatial frequencies at 1.5, 3, 6, 12, and 18 cycles per degree (cpd).Results: The contrast sensitivity increased after PTK at 1.5 and 3 cpd in mesopic and photopic conditions with G0-2 glare (p < 0.05). At 6 cpd, the contrast sensitivity increased in the mesopic condition with G1 glare, and in the photopic condition with G0-2 glare (p < 0.05). However, there was no change in contrast sensitivity at any glare level at 12 and 18 cpd after PTK.Conclusions: In GCD2 patients, the contrast sensitivity increased significantly after PTK. The vision of GCD2 patients, which is decreased due to corneal opacity, is improved after PTK.

Implications of Corneal Refractive Surgery in Patients with Fabry Disease

Fabry disease is an X-linked lysosomal storage disorder involving abnormal metabolism of glycosphingolipids, resulting in a range of multisystem organ dysfunction and ocular manifestations. Reports of laser-assisted in situ keratomileuses (LASIK) and photorefractive keratectomy (PRK) are lacking in this patient population. Proceeding with corneal refractive surgery in patients with Fabry disease raises concerns regarding the pre-existing corneal manifestations, reduced mesopic visual acuity, the potential for conjunctival lymphangiectasia, and predisposition to dry eye syndrome. This commentary discusses the current understanding of Fabry disease, including its ocular manifestations, and explores factors to consider when evaluating these patients for LASIK or PRK.