In vivo microstructural analysis of the cornea in Scheie's syndrome

PURPOSE: To analyze clinical and in vivo microstructural characteristics of both corneas of a 13-year-old male subject with Scheie's syndrome and compare the observations with the pathologic reports in the literature. METHODS: Standard clinical examination and real-time, slit-scanning in vivo confocal microscopy were performed and repeated after 1 year. RESULTS: In vivo confocal microscopy images at all cellular layers demonstrated brighter intercellular spaces than those of normal corneas. Cicatrization of the anterior stroma was identified, and the keratocytes of the middle and posterior stroma exhibited markedly altered morphology, often round or elliptical in shape, and with clearly demarcated, hyporeflective centers. The nerve fibers of the subbasal plexus were somewhat more irregular and difficult to distinguish, possibly due to underlying fibrosis. CONCLUSIONS: The potential of in vivo confocal microscopy to highlight microstructural alterations of the intact human cornea and evaluate such changes over time might reduce reliance on histopathologic investigations in such conditions and contribute to the ophthalmic management of the mucopolysaccharidoses in the future.     

Histological and ultrastructural studies of the cornea in Maroteaux-Lamy syndrome

The author presents the histologic and electron-microscopic examination of the cornea of a patient with Maroteaux-Lamy syndrome. Histochemic examinations established the absence of keratin sulfate and heparin sulfate in the accumulated material. By means of electron microscopy three cell types have been found in the stroma which may show, besides the storage of the accumulated glycosaminoglycans, the morphologic signs of the pathologic enzyme-substrate connection. Considering the presence of the lipidlike material, the question arises whether the Maroteaux-Lamy syndrome belongs to mucolipidoses.

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Zusammenfassung Bericht über die histologische und elektronenmikroskopische Untersuchung der Hornhaut bei Maroteaux-Lamy Syndrom. Histochemisch wurde im Speichermaterial das Fehlen von Keratansulfat und Heparansulfat festgestellt. Im Stroma befinden sich drei Zelltypen, die außer der Speicherung der angehäuften Glycosaminoglycans morphologisch für eine pathologische Enzym-Substrat-Verbindung sprechen. Auf Grund der Anwesenheit des Lipid-ähnlichen Materials stellt sich die Frage, ob das Maroteaux-Lamy Syndrom zu den Mucolipidosen gehört.

     

In vivo confocal microscopic findings of two siblings with Maroteaux-Lamy syndrome

PURPOSE: To describe the clinical and in vivo confocal microscopic findings of the cornea in 2 male siblings with Maroteaux-Lamy syndrome. METHODS: Two male siblings 27 and 22 years of age who had been diagnosed with Maroteaux-Lamy syndrome underwent ophthalmologic assessment. In vivo confocal microscopy of their corneas was performed with Confoscan 3.0 (Vigonza, Italy). RESULTS: Slit-lamp examination of the central and peripheral corneas of both siblings revealed mild haze and diffuse stromal opacities. The fundus examination of the older sibling was significant for left optic disc swelling and bilateral radial macular folds. In vivo confocal microscopy of the corneas of both cases revealed several microdeposits that were present extracellularly and within keratocytes in all stromal layers, ranging in size from 1.0 to 3.8 microm. Abnormal keratocytes containing hyporeflective vacuoles were present to a greater extent in the posterior and middle stromal layers compared with the anterior stroma. The endothelial cell layer, the subbasal nerve plexus, and the stromal nerves had normal morphologic features. CONCLUSIONS: In corneas of patients with Maroteaux-Lamy syndrome, glycosaminoglycan deposition and abnormal keratocytes may be present in all stromal layers. The endothelial layer seems to be normal at the third decade of life in both subjects studied.     

Glaucoma in the Maroteaux-Lamy syndrome

We report four patients who had glaucoma in association with the Maroteaux-Lamy syndrome. Two of these patients had acute angle-closure glaucoma, one had chronic angle-closure glaucoma, and one was treated for open-angle glaucoma; however, the angle structures could not be seen by gonioscopy. Standard peripheral iridectomy was inadequate for treatment of this angle-closure glaucoma because of the considerably increased thickness of the peripheral cornea that occurs in these patients. Our findings suggest that glaucoma may be more common in the Maroteaux-Lamy syndrome than has been realized and that the initial mechanism is secondary acute or chronic angle closure not related to pupillary block.     

In vivo confocal microstructural analysis and surgical management of Brown-Mclean syndrome associated with spontaneous crystalline lens luxation

We report 3 members of an extended family who presented with bilateral peripheral corneal edema consistent with Brown-McLean syndrome. On clinical examination, all eyes demonstrated normal central corneas and marked peripheral edema. In vivo confocal microscopy of the peripheral cornea highlighted similar observations in the 6 eyes including endothelial pigmentation, masked stromal structure due to edema, prominent nerves, and localized basal epithelial edema. In the central cornea, in vivo confocal microscopic observations highlighted large cellular structures with prominent nuclei in groups consisting of several cells of similar appearance. In vivo confocal microscopy may enhance the diagnosis of Brown-McLean syndrome and may be used for dynamic evaluation and postoperative follow-up of the structural corneal changes.     

In vivo confocal microscopy of the human cornea

AIMS: To describe the optics of in vivo confocal microscopy, its advantages over previous methods, and to summarise the literature that arose from its use for the observation of the human cornea. A critical review of the clinical usefulness of this new technology for the corneal examination is undertaken. METHODS: Confocal microscopes obtain increased resolution by limiting the illumination and observation systems to a single point. Rapid scanning is used to reconstruct a full field of view and allows for "real time" viewing. RESULTS: Coronal sections of the in situ epithelium, Bowman's membrane, stroma, and endothelium can be visualised at a resolution of 1-2 micro m. A backscattered light intensity curve allows objective measurements of sublayer thickness and corneal haze to be taken. In vivo confocal microscopy is therefore particularly useful in the areas of infective keratitis, corneal dystrophies, refractive surgery, and contact lens wear, where it aids in differential diagnosis and detection of subtle short and long term changes. Real time endothelial cell assessment can also be performed. CONCLUSION: Because of their ability to visualise living tissue at cellular levels, confocal microscopes have proved useful additions to the current clinical tools.     

In vivo oxygen uptake into the human cornea

Purpose. We provide a new procedure to quantify in situ corneal oxygen uptake using the micropolarographic Clark electrode. Methods. Traditionally, upon placing a membrane-covered Clark microelectrode onto a human cornea, the resulting polarographic signal is interpreted as the oxygen partial pressure at the anterior corneal surface. However, the Clark electrode operates at a limiting current. Hence, oxygen flux is directly detected rather than partial pressure. We corrected this misunderstanding and devised a new analysis to quantify oxygen uptake into the cornea. The proposed analysis is applied to new polarographic data for 10 human subjects during open-eye oxygen uptake. Results. Average open-eye corneal oxygen uptake over 10 subjects is approximately 11 μL/(cm(2) h), approximately five times larger than the average reported by researchers who invoke the original mathematical analysis. Application of the classical interpretation scheme to our experimental data also garners uptake values that are approximately a factor of three to five times smaller than those obtained with our new procedure. Conclusions. The classical procedure originally developed by Fatt and colleagues misinterprets the behavior of the Clark microelectrode. We corrected the analysis of the in situ polarographic technique to provide a simple yet rigorous procedure for analyzing both previous data in the literature and those newly obtained. Our proposed interpretation scheme thus provides a reliable tool for in vivo assessment of corneal oxygen uptake.     

In vivo laser confocal microscopic analysis of murine cornea and lens microstructures

BACKGROUND AND OBJECTIVE: The purpose of the current study is to investigate in vivo microstructures of anterior segments of normal murine eyes by new-generation in vivo laser confocal microscopy. MATERIALS AND METHODS: Twenty-six corneas and lenses from 13 mice were analyzed by in vivo laser confocal microscopy. RESULTS: Murine corneal superficial cells formed a polygonal cell pattern, with a mean cell density of 577 +/- 115 cells/mm2 (mean +/- standard deviation). Corneal basal epithelial cells had dark cytoplasm and were closely organized (9,312 +/- 1,777 cells/mm2). Sub-basal nerve fiber bundles were arranged in a whorl pattern, with both clockwise and counter-clockwise patterns. In the stroma, keratocytes were observed as numerous reflective stellate structures. The endothelial cells were organized in a honeycomb pattern (2,463 +/- 292 cells/mm2). Deeper inside the eye, murine lens epithelial cells were organized in a regular pattern (4,168 +/- 636 cells/mm2) and numerous lens fibers were observed. CONCLUSION: In vivo laser confocal microscopy can provide high-resolution images of all corneal layers and lens structures of mice without sacrificing animals or tissue preparation.     

In vivo confocal microscopy in the patients with cornea farinata

PURPOSE: To report in vivo corneal confocal microscopic findings of patients with cornea farinata. PATIENTS AND METHODS: Two unrelated patients, a 47-year-old man and a 77-year-old woman, with cornea farinata were studied. Examination with a confocal microscope was performed in addition to routine slit-lamp biomicroscopy. RESULTS: In both cases, slit-lamp biomicroscopy showed numerous small, faint opacities in the deep stroma in both eyes. Using confocal microscopy, highly reflective small particles were observed in the cytoplasm of keratocytes in the deep stroma adjacent to the corneal endothelial layer. No abnormalities could be detected in the epithelial layer, in the mid-stromal layer, at the level of Descemet's membrane, and in the endothelial layer. CONCLUSIONS: In vivo corneal confocal microscopy is useful for observing stromal abnormalities in cornea farinata. Further investigation of posterior stromal opacities using confocal microscopy may be useful to understand and differentiate various corneal conditions involving primarily deep stromal layers.     

In vivo fibroplasia of a porous polymer in the cornea.

We have developed a melt-blown fibrous construction of polybutylene/polypropylene in which we previously demonstrated keratocyte ingrowth and collagen synthesis in vitro. In the present studies, we evaluated this material in vivo in interlamellar corneal pockets for periods of up to six months. By day 42, the porous interstices of the disc were heavily populated with keratocytes. Extracellular matrix deposition occurred and there was a 5000-fold increase in total protein and a 1000-fold increase in total collagen over background. The cells within the disc continued to be synthetically active for the six months of our study. Discs remained in corneas for periods of up to one year without any extrusion. This material has great promise as a porous peripheral component of a keratoprosthetic device.     

In vivo confocal Raman spectroscopy of the human cornea.

PURPOSE: To investigate the feasibility of a confocal Raman spectroscopic technique for the noninvasive assessment of corneal hydration in vivo in two legally blind subjects. METHODS: A laser beam (632.8 nm; 15 mJ) was maintained on the cornea by using a microscope objective lens (x25 magnification, NA = 0.5, f = 10 mm) both for focusing the incident light as well as collecting the Raman backscattered light, in a 180 degrees backscatter configuration. An optical fiber, acting as the confocal pinhole for elimination of light from out-of-focus places, was coupled to a spectrometer that dispersed the collected light onto a sensitive array detector for rapid spectral data acquisition over a range from 2,890 to 3,590/cm(-1). Raman spectra were recorded from the anterior 100-150 microm of the cornea over a period before and after topical application of a mild dehydrating solution. The ratio between the amplitudes of the signals at 3,400/cm(-1) (OH-vibrational mode of water) and 2,940/cm(-1) (CH-vibrational mode of proteins) was used as a measure for corneal hydration. RESULTS: High signal-to-noise ratio (SNR = 25) Raman spectra were obtained from the human corneas by using 15 mJ of laser light energy. Qualitative changes in the hydration of the anteriormost part of the corneas could be observed as a result of the dehydrating agent. CONCLUSION: With adequate improvements in system safety, confocal Raman spectroscopy could potentially be applied clinically as a noninvasive tool for the assessment of corneal hydration in vivo.     

共焦显微镜对翼状胬肉及其周围角膜的组织病理学观察

目的 探讨角膜共焦显微镜下翼状胬肉及其周围角膜的组织病理学和细胞学特征.方法 前瞻性自身对照研究.单眼初发性翼状胬肉患者40例,应用角膜共焦显微镜观察胬肉形态,对侧无胬肉眼为对照.记录翼状胬肉、中央角膜、翼状胬肉周边角膜各层细胞图像,并对各层细胞形态、密度的结果采用配对t检验进行分析.结果 共焦显微镜下翼状胬肉的表层细胞胞体发亮,边界发暗,胬肉基质中可见毛细血管内血流,有时可见内含小圆形细胞的微囊样结构及Langerhans细胞.翼状胬肉周边角膜翼状上皮细胞、基底上皮细胞形态不规则,部分被拉长并扭曲;中央及周边各层上皮细胞平均密度小于对照眼(t=-3.92、-3.55、-3.36、-2.61、-4.31、-4.11,P均＜0.05);翼状胬肉眼角膜上皮下Langerhans细胞平均密度大于对照眼(t=3.75、4.23,p均＜0.05);角膜上皮基底细胞层下神经纤维比较杂乱,神经弯曲度大(t=5.02,P＜0.01),分支多(t=2.51,P＜0.05).结论 共焦显微镜可观察到翼状胬肉细胞水平的特征.翼状胬肉患者胬肉周边角膜上皮细胞、上皮下Langerhans细胞、上皮基底细胞层下神经、前基质细胞及角膜厚度均有变化.     

In vivo confocal laser scanning microscopy of the cornea in dry eye

Background We carried out an investigation into the morphological and quantitative corneal properties in dry eye with various underlying pathologies.Methods Ten patients with aqueous tear deficiency, 8 with dysthyroid ophthalmopathy, 8 with chronic lagophthalmos and 10 normal participants were examined. Confocal microscope images were taken at the centre and at the lower and upper periphery of the cornea. Quantitative and morphological assessments of the epithelium, of the sub-basal nerves, of the stroma and the endothelium were made. The epithelial and corneal thicknesses were measured.Results The mean superficial and intermediate epithelial cell densities in the central cornea in the patient groups were significantly lower than in normal participants (p<0.01). The peripheral epithelial thickness was smaller (p<0.01); it was smallest in the lagophthalmos group. The cornea was thinner in the patient groups (p<0.01). For sub-basal nerves, the density had decreased (p<0.05), and in lagophthalmos the number of beadlike formations had increased (p<0.001); in some patients we found irregular branching patterns.Conclusions Dry eye patients showed significant alterations in the cornea, presumably due to increased desquamation of the superficial cell layer. This was most pronounced at the lower periphery of the cornea in patients with exposure keratopathy.The authors had no financial relationship with the organisation that supported the research.The authors had full control of all primary data and agree to allow Graefe’s Archive for Clinical and Experimental Ophthalmology to review the data if requested.The results were partly presented at DOG in 2005.     

In vivo confocal microstructural analysis of corneal endothelial changes in a patient on long-term chlorpromazine therapy

Background Deposits in the cornea and lens are a known complication of long-term chlorpromazine therapy.Method A 59-year-old woman had previously taken chlorpromazine for 20 years with doses up to 1,200 mg/day, with a mean dose of 400 mg/day. She presented with gradual onset of blurred vision in her left eye. Slit-lamp biomicroscopy revealed multiple fine creamy-white deposits on her corneal endothelium and anterior crystalline lens capsule bilaterally.Results In vivo confocal microscopy of the cornea identified irregular hyper-reflective deposits on the posterior surface of the endothelium. The deposits varied from 1 m to 70 m in diameter and had well-defined edges. Endothelial morphology was otherwise normal bilaterally.Conclusions This is the first report of in vivo confocal imaging of deposits resulting from long-term chlorpromazine use. Microstructural analysis of the corneal endothelium reveals that there were no abnormalities in cellular morphology resulting from these deposits.     

Occurrence of mucopolysaccharide in corneal grafts in the Maroteaux-Lamy syndrome

We describe the histopathologic and ultrastructural features of corneal buttons from the original and repeat corneal grafts of two patients with the Maroteaux-Lamy syndrome (MPS VI-B). The donor cornea, in place for 10 years in one patient, had recurrence of mucopolysaccharide in the corneal epithelium, fibrocytes in the pannus, corneal stroma, retrocorneal fibrous tissue layer, and endothelium. The donor cornea, in place for 1 year in the second patient, had recurrence of mucopolysaccharide in the epithelium, minor deposits in the superficial stroma, and larger deposits in the stroma near the keratoplasty scar.     

The cornea in Sjogren's syndrome: an in vivo confocal study

PURPOSE: To analyze the in vivo morphology of corneal cells and nerves in dry eye associated with primary (SSI) and secondary (SSII) Sj?gren's syndrome and to study its relationship with the clinical evaluation. METHODS: Thirty-five patients with SS and 20 age- and gender-matched control subjects were studied. Confocal microscopy was used to investigate corneal thickness, epithelial and stromal cellular density, and subbasal plexus morphology. RESULTS: Corneal central thickness was 514.74 +/- 19.85 microm in the SS group and 550 +/- 21.46 microm in the control group (P < 0.0001, t-test); stromal central thickness was 456.62 +/- 18.05 microm in the SS group and 487.35 +/- 20.40 microm in the control group (P < 0.0001). The density of the superficial epithelial cells in the SSI and SSII groups was 965.40 +/- 96.00 and 999.80 +/- 115.67 cells/mm(2), respectively, and 1488.55 +/- 133.74 cells/mm(2) in the control group (P < 0.001, ANOVA). The number of subbasal nerves was 3.34 +/- 0.76 in the SS group and 5.10 +/- 0.79 in the control group (P < 0.0001, t-test). The average grade of nerve tortuosity was 2.62 +/- 0.94 in the SS group and 1.20 +/- 0.70 in the control group (P < 0.0001). Statistically significant correlations were found between clinical data and confocal microscopy data. CONCLUSIONS: Corneal thickness, cells, and nerves show morphologic changes in patients with dry eye associated with SS. The in vivo confocal study of these alterations may be important in better understanding the complexity of the ocular surface morphofunctional unit and the potentials of therapeutic approaches for the control of the phlogistic process and neuroprotection.