Original articleIn Vivo Confocal Microscopy and Anterior Segment Optical Coherence Tomography Analysis of the Cornea in Nephropathic Cystinosis
Section snippets
Patients and Methods
Eight patients with infantile nephropathic cystinosis were included in this study. There were 6 females and 2 males with a mean age of 12.5±4.6 years (range, 8–21). Nephropathic cystinosis was diagnosed based on a typical clinical presentation and a leukocyte cystine concentration >3 nmol half-cystine per milligram of protein. All patients took systemic cysteamine (Cystagon, Orphan Europe, Paris, France) and cysteamine eye drops (cysteamine hydrochloride 0.1%, Pharmacie Centrale des Hôpitaux de
Results
The 16 eyes of the 8 patients were evaluated in this study. All patients had normal or a near-normal visual acuity, with a mean best-corrected visual acuity of 0.08±0.13 logarithm of the minimum angle of resolution (range, 0.3 to −0.06). Mean photophobia was 2.47±0.92 (range, 1–4). Mean intraocular pressure was 11.53±2.33. All eyes had corneal crystal deposits, with a mean slit-lamp photography score of 2.90±0.13 (range, 2.75–3.00; Fig 2). Clinical data are summarized in Table 1.
Using AS-OCT,
Discussion
The IVCM images provided a precise, qualitative, and quantitative assessment of crystal deposition within the cornea of patients with nephropathic cystinosis. To our knowledge, the description of these deposits using IVCM has already been presented, but only in 4 individual case reports and with controversial findings concerning the presence of crystals within the epithelium, the corneal layer with the highest crystal density, and the orientation of these crystals.13, 14, 15, 16 In the study
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In vitro and ex vivo implantation of cystine crystals and treatment by contact lens
2019, Colloids and Surfaces A: Physicochemical and Engineering AspectsPotential role of stromal collagen in cystine crystallization in cystinosis patients
2018, International Journal of PharmaceuticsCitation Excerpt :Cystinosis is commonly treated with cysteamine (β-mercaptoethylamine) (Cantani et al., 1983; Gahl et al., 1985; Iwata et al., 1998; Jones et al., 1991; Kimonis et al., 1995; Simpson et al., 2011; Tavares et al., 2009; Thoene et al., 1976; Tsilou et al., 2003) which reacts with intralysosomal cystine to produce mixed disulfide cysteine-cysteamine dimers and the amino acid cysteine (Bradbury et al., 1991; Kaiser-Kupfer et al., 1987, 1990; MacDonald et al., 1990). These are transported out of the lysosome via the lysine transport system, bypassing the damaged cystinosis transporter (Labbe et al., 2009). In the eyes though, a majority of the cystine is extra-cellular, i.e., it is dispersed in the water like stoma layer of the cornea.
Ocular Complications of Infantile Nephropathic Cystinosis
2017, Journal of PediatricsCitation Excerpt :There is evidence for crystal accumulation in all layers of the cornea, with cornea stroma involvement being the most significant examination finding. Corneal crystals are typically present in the corneal periphery by 16 months of age, and advance to saturate the cornea by early adolescence if left untreated.7 Although difficult to appreciate on slit-lamp examination, crystals can be visualized in corneal epithelial cells by in vivo confocal microscopy8 and histopathology.6
Effect of pH and penetration enhancers on cysteamine stability and trans-corneal transport
2016, European Journal of Pharmaceutics and BiopharmaceuticsCitation Excerpt :Oral administration favorably treats systemic symptoms [4], but is completely ineffective for ocular manifestations since the cornea, as a consequence of the angiogenic privilege, is an avascular tissue. Therefore, the only possible approach for the effective decrease in corneal cystine crystals responsible for photophobia, keratopathies and frequent corneal erosions [5], is the topical administration of the drug. FDA has recently approved Cystaran™, a cysteamine hydrochloride based eye-drop effective in the reduction in corneal cystine crystals [6].
A Comparative Pharmacokinetic Study for Cysteamine-Containing Eye Drops as an Orphan Topical Therapy in Cystinosis
2024, International Journal of Molecular Sciences
Manuscript no. 2008-1115.
Financial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article.
Supported by Quinze-Vingts National Ophthalmology Hospital, Paris, France.