Fabry keratopathy: manifestations and changes over time

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.

SD-OCT Imaging of Macular Changes in Fabry Disease: A Case Report

Fabry disease (FD) is a rare, X-linked lysosomal storage disorder that can result in fatal end-stage renal disease, heart failure, and cerebro-occlusive events. Vague clinical symptoms and rarity often mean diagnosis and potential treatment is delayed. Ophthalmic findings in FD patients can be helpful in establishing an early diagnosis and timely treatment. Spectral domain optical coherence tomography (SD-OCT) imaging in FD patients shows hyper-reflective foci (HRF) in characteristic patterns within the inner retinal layers. We found that the HRF was localised in linear distributions at the deep and superficial borders of the retinal inner nuclear layer, likely reflecting anatomic vascular plexuses and FD-related sphingolipid deposition within the vessel walls. These results highlight the potential use of SD-OCT in FD and how it may aid diagnosis in undifferentiated patients, prognostication, and disease monitoring.

Impact of Nontreatment Duration and Keratopathy on Major Adverse Cardiovascular Events in Fabry Disease: A Nationwide Cohort Study

Fabry disease (FD) is a rare inherited X-linked lysosomal storage disorder that results in the progressive accumulation of glycosphingolipids in multiple organs. Early FD-specific treatments may improve clinical outcomes; however, clinical evidence about early FD treatment is limited. We aimed to determine the cardiovascular outcomes of patients with FD who received enzyme replacement therapy. This nationwide observational study was conducted using the National Health Claims database of the Korean population with FD. The primary outcome was major adverse cardiovascular events (MACEs). MACE risk factors in FD were evaluated using time-dependent Cox regression. Between January 2007 and April 2022, 188 patients with FD were analyzed. Among them, 22 (11.7%) experienced MACE (males: 14/95 [14.7%]; females: 8/93 [8.6%]). The mean age at MACE diagnosis was 53.5 ± 11.0 years in all patients with FD, which was lower in males compared with in females (49.7 ± 9.6 vs. 60.0 ± 10.7 years, p = 0.030). Multivariate analysis (HR, 95% CI) revealed that age (1.042; 1.004-1.082) and duration of FD nontreatment (1.040; 1.003-1.078) were significant MACE risk factors in all patients. In males, age (1.080; 1.032-1.131), FD nontreatment duration (1.099; 1.048-1.152), and keratopathy (18.920; 4.174-85.749) were significant MACE risk factors in multivariate analysis. In females, the only significant MACE risk factor was a high Charlson comorbidity index score (1.795; 1.229-2.622). In conclusion, duration of FD nontreatment and keratopathy are significant MACE risk factors in males with FD. These findings suggest the importance of early initiation of FD-specific treatment and careful evaluation of keratopathy in males with FD.

Visual outcome, ocular findings, and visual quality of life in patients with Fabry disease

BACKGROUND

Fabry disease (FD) is an X-linked lysosomal disease, in which diagnosis is often established several years after onset of symptoms. Ocular manifestations can occur in childhood and be a clue to earlier diagnosis. The aim was to report ocular outcome and visual quality of life (QoL) in patients with FD.

MATERIAL AND METHODS

FD-patients recruited from Karolinska University Hospital underwent ophthalmological examinations including best corrected visual acuity (BCVA), refraction, biomicroscopy, optical coherence tomography, keratometry, review of medical records and QoL Inventories. A total severity score (TSS), as estimated via Fabry Stabilization Index, was calculated.

RESULTS

Twenty-six FD-patients (16 men) mean age 36.4 years (range 5.0-63.5 years) were included. BCVA was median 1.0 (range 0.5-1.6). Conjunctival blood vessel tortuosity occurred in 15/26 patients, chemosis in 2/26 patients, cornea verticillata in 23/26 patients, lens opacities in 19/26 patients, and tortuous or dilated retinal vessels in 20/25 patients. Group-wise comparisons of adult patients showed no differences regarding age, TSS, or ocular parameters. Overall, TSS was correlated to age (r = 0.53, p = 0.02). A linear regression model showed that age and sex explained 38% of the variance in TSS. Keratometry did not reveal corneal ectasia in any of the 12 patients examined. VFQ 25 in 15 patients showed a high median composite score, 93.6 (range: 78.1-100).

CONCLUSIONS

BCVA in FD-patients was good despite corneal and lens pathology. Ocular variables did not show an association with TSS in adult patients. Corneal or lens opacities should also lead to a suspicion of FD in children.

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.