Assessment of corneal topographic, tomographic, densitometric, and biomechanical properties of Fabry patients with ocular manifestations

Corneal densitometry: A new evaluation indicator for corneal diseases

Corneal densitometry (CD) uses the biological properties of the cornea to visualize the morphology of the cornea and determine the degree of corneal transparency. At present, it is an emerging metric that has shown promise in various clinical diagnosis and evaluation of eye diseases and surgeries. We introduce the different methodologies used to measure CD. Furthermore, we systematically categorize the diagnostic value of CD into high, medium, and low levels based on its clinical significance. By analyzing a wide range of conditions, including keratoconus, postrefractive surgery changes, and other corneal pathologies, we assess the utility of CD in each context. We also discuss the potential implications of these classifications for disease monitoring and prognosis evaluation. Our review underscores the importance of integrating CD assessments into routine clinical practice to enhance the accuracy and effectiveness of diagnostic processes for corneal disorders.

Tomographic, Biomechanical, and In Vivo Confocal Microscopic Changes in Cornea in Chronic Gout Disease

PURPOSE

This study aimed to evaluate the tomographic, biomechanical, and in vivo confocal microscopic (IVCM) effects of chronic gout disease on human cornea.

METHODS

This prospective study included 60 eyes of 30 participants with chronic gout disease and 60 eyes of 30 healthy controls. Corneal thickness, keratometry (K) readings, and corneal aberrations were measured with Sirius 3 D corneal tomography system (Sirius, CSO, Italy). Corneal biomechanical properties (corneal hysteresis [CH], corneal resistance factor [CRF], and intraocular pressure [IOP] parameters) were assessed with an ocular response analyzer (ORA, Reichert Ophthalmic Instruments). The number and morphology of corneal endothelial cells and the number of basal epithelial cells were evaluated with IVCM (Confoscan 4.0). Tear breakup time (TBUT) was also evaluated.

RESULTS

The mean diagnosis time of the patients with gout was 91.2 ± 69.6 months (12-300 month). Among corneal tomography measurements, K readings were similar between the two groups, while total and higher-order aberrations(coma, trefoil,s pherical, and quadrafoil) were significantly higher in the gout group. In the evaluation of biomechanical measurements, the CH value was significantly lower and the corneal-compensated IOP value was significantly higher in the gout group (p = 0.02, p = 0.01, respectively). The two groups did not significantly differ regarding the CRF or Goldmann IOP (p = 0.61, p = 0.15, respectively). Among the IVCM parameters, the number of corneal basal epithelial cells and the percentage of corneal endothelial hexagonality were significantly lower in the gout group, but no significant difference was detected in terms of the number of endothelial cells or polymegathism (p = 0.02, p < 0.001, p = 0.18, p = 0.59, respectively). While TBUT was significantly lower in the gout group (p < 0.001).

CONCLUSION

This study showed that chronic gout disease increases the corneal aberrations and decreases the basal epithelial cell count, hexagonality ratio of endothelial cell and corneal biomechanics.

Anderson-Fabry Disease: Focus on Ophthalmological Implications

Fabry disease (FD) is a rare X-linked lysosomal storage disorder with a broad spectrum of clinical manifestations, including severe complications, such as end-stage renal disease, hypertrophic cardiomyopathy, and cerebrovascular disease. Enzyme replacement therapy (ERT), when initiated early, has been shown to reduce the incidence of severe events and slow disease progression. In the classic form, characterized by the absence of α-galactosidase A (α-Gal A) enzyme activity, diagnosis is straightforward. However, when residual activity is present, the delayed and less obvious presentation can make diagnosis more challenging. Ophthalmological alterations, which can be detected through non-invasive examinations may play a crucial role in correctly assessing the patient in terms of diagnosis and prognosis, particularly in these atypical cases. Recognizing these ocular signs allows for timely intervention with ERT, leading to improved patient outcomes. This review highlights the importance of ophthalmological findings in FD, emphasizing their role in diagnosis and treatment planning. By raising awareness among ophthalmologists and healthcare specialists, this review aims to improve disease management, offering tools for early detection and better long-term prognosis in patients with FD.

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.

Investigation of corneal topographic and densitometric properties of Wilson's disease patients with or without a Kayser-Fleischer ring

BACKGROUND

To investigate the topographic measurements and densitometry of corneas in Wilson's disease (WD) patients with or without a Kayser-Fleischer ring (KF-r) compared to healthy individuals.

METHODS

This cross-sectional study included 20 WD patients without a KF-r (group I), 18 WD patients with a KF-r (group II), and 20 age-matched controls (group III). The Pentacam high resolution imaging system is used to determine corneal topographic measurements and densitometry.

RESULTS

Mean age for groups I, II and III was 25.40 ± 6.43 years (14-36 years), 25.38 ± 6.96 years (16-39 years), 23.60 ± 6.56 years (17-35 years), respectively (P = 0.623). There was no significant difference between the groups in terms of the anterior corneal densitometry values (P > 0.05), while the 6-10 mm and 10-12 mm mid stroma and the 2-6 mm, 6-10 mm, and 10-12 mm posterior corneal densitometry values in group II were significantly higher than those in groups I and III (for all values, P <  0.05). However, the 10-12 mm posterior corneal densitometry values in group I were also significantly higher than those in group III (P = 0.038). The central corneal thickness (CCT), thinnest corneal thickness (tCT), and corneal volume (CV) values in groups I and II were significantly lower than those in group III (for CCT values, P = 0.011 and P = 0.009; for tCT values, P = 0.010 and P = 0.005; for CV values, P = 0.043 and P = 0.029).

CONCLUSION

In WD patients with a KF-r, corneal transparency decreased in the peripheral posterior and mid stromal corneal layers; for these patients, corneal transparency may be impaired not only in the peripheral cornea but also in the paracentral cornea.

Analysis of the alpha galactosidase gene: mutation profile and description of two novel mutations with extensive literature review in Turkish population

Objectives Fabry disease (FD, OMIM #301500) is a rare and progressive X-linked lysosomal storage disorder. FD is caused by mutations in the GLA gene on chromosome Xq22. Methods In this article, we aimed to present the largest sample of GLA mutation spectrum including common and novel variants in Turkish population. GLA gene sequence analysis was performed on the subjects who applied to the department of medical genetics with the preliminary diagnosis of FD between 2013 and 2018. Results We detected 22 different mutations as two novel [(p.F69S(c.206T>C), p.P205A (c.613C>G)] and 20 previously reported GLA mutations in 47 individuals from 22 unrelated families. These mutations included 14 missense mutations, four nonsense mutations, two small deletions, one small deletion/insertion and one small insertion. Major clinical findings of the female case with p.F69S(c.206T>C) mutation were cornea verticillata, acroparesthesia, angiokeratoma, psychiatric and gastrointestinal symptoms. Other novel mutation (p.P205A [c.613C>G]) was carried by a male case presenting gastrointestinal symptoms. Conclusions We described clinical findings of two cases that had novel mutations to provide more insight in genotype-phenotype correlation. We presented the largest mutation spectrum in Turkish population and reviewed previous mutations in this article.