Confocal microscopy in posterior polymorphous corneal dystrophy.

PURPOSE: To report the distinguishing characteristics of posterior polymorphous corneal dystrophy (PPMD) using confocal microscopy. MATERIAL AND METHODS: Two consecutive patients with PPMD were prospectively examined using a white-light tandem scanning confocal microscope with a 24x/0.60 contact objective. RESULTS: At the level of Descement's membrane, roundish hyporeflective images were found in 1 patient. In the other patient, hyporeflective bands were detected. In both patients, patchy hyperreflective areas were identified. CONCLUSION: Confocal microscopy may allow diagnosis of PPMD by demonstrating the alterations in Descement's membrane. This technique is especially valuable in cases of endothelial decompensation, where slit-lamp and specular microscopy may fail to demonstrate changes in Descement's membrane.     

In vivo confocal microscopy of climatic droplet keratopathy

We describe the corneal microstructural changes in a patient with spheroidal degeneration using in vivo confocal microscopy. Multiple hypo‐ and hyper‐reflective spherical lesions were observed in the anterior corneal stroma and Bowman's layer ranging from 45 to 220 μm in size. The corneal epithelium, posterior stroma and endothelium were otherwise unaffected. In vivo confocal microscopy demonstrates good correlation with excised histological samples in climatic droplet keratopathy. It provides a non‐invasive technique to examine the living cornea for degenerative disease and acts as a bridge between clinical and laboratory observations.     

Microstructural assessment of rare corneal dystrophies using real-time in vivo confocal microscopy

Purpose : To analyse and describe three cases of rare corneal dystrophy and highlight their in vivo microstructural features. Methods : Subject 1 was diagnosed with a posterior stromal fleck corneal dystrophy. Two of her three children were also affected. Subjects 2 and 3 exhibited an almost identical clinical appearance on biomicroscopic examination, such that both clinically were diagnosed as having pre‐Descemet’s dystrophies. All subjects underwent in vivo confocal microscopy and approximately 300 sequential digital images were obtained and analysed for each cornea. Results : In vivo confocal microscopy of subject 1 demonstrated an abnormal appearance of numerous large ovoid particles, measuring 50–70 μm in diameter in the mid and posterior stroma as well as smaller hyperreflective dot‐like intracellular deposits, of less than 1 μm diameter. Despite the near‐identical clinical appearance, subjects 2 and 3 could be clearly differentiated by in vivo confocal microscopy. Subject 2 exhibited small, irregular, optically dense particles, mainly in the anterior stroma, whereas subject 3 possessed classical involvement of the stroma immediately adjacent to Descemet’s membrane, with numerous regular, small, hyperreflective particles. Conclusions : The ability of in vivo confocal microscopy to localize and accurately measure various elements in different corneal layers may help to resolve whether abnormalities are intra‐ or extracellular, and aid clearer differentiation of rare corneal disorders.     

Dystrophia Helsinglandica – corneal morphology,topography and sensitivity in a hereditary corneal disease with recurrent erosive episodes

Purpose: The aim of this study was to describe the morphology, corneal topography and sensitivity in individuals with Dystrophia Helsinglandica. This autosomal dominant corneal disease is characterized by recurrent corneal erosive episodes and progressive subepithelial fibrosis not significantly affecting visual acuity. Methods: The corneas of nine affected and nine unaffected individuals were examined using slit‐lamp biomicroscopy, in vivo confocal microscopy (IVCM) and videokeratography. Corneal mechanical sensitivity was also measured using a non‐contact esthesiometer. Results: Slit‐lamp biomicroscopy revealed that the affected individuals represented different stages of corneal changes, from a nearly normal cornea to subepithelial fibrosis of the central cornea. Corneal changes in affected individuals did not significantly decrease the best spectacle‐corrected visual acuity. In vivo confocal microscopy detected morphological changes in the epithelium and stroma. Subepithelial opacity formation including altered keratocytes could be found in the anterior stroma in all affected eyes. With the exception of two eyes (one affected and one unaffected), all videokeratographies showed irregular astigmatism. Corneal sensitivity was significantly lower in affected individuals (p = 0.01). Age and corneal sensitivity showed no correlation. Conclusion: The main morphological findings in affected individuals were discrete and progressive subepithelial fibrosis, in the in vivo confocal microscope corresponding to optically dense extracellular matrix and activated keratocytes. Subbasal nerve morphology was changed in the affected family members who also showed a decreased corneal sensitivity. The findings are per se not specific to the disease. The changes probably reflect a healing response to erosive events on the corneal surface influenced by the genotype.     

In vivo confocal laser-scanning microscopy to characterize wound repair in rabbit corneas after collagen cross-linking

Background: Collagen cross‐linking using the photosensitizer riboflavin combined with ultraviolet A light was developed to stiffen the cornea by increasing its mechanical and biochemical stability. Investigation of post‐treatment events, such as wound healing, is important to evaluate possible risks and to optimize treatment protocols. This in vivo confocal laser‐scanning microscopy study in rabbits was conducted to provide a quantitative and qualitative analysis of corneal wound repair over 16 weeks following collagen cross‐linking. Methods: Six New Zealand White rabbits underwent riboflavin/ultraviolet A cross‐linking. In vivo confocal laser‐scanning microscopy using a Heidelberg Retina Tomograph equipped with a Rostock Cornea Module was performed preoperatively and at 2, 4, 8, 12 and 16 weeks postoperatively. Results: From 2 weeks onwards the epithelium demonstrated no abnormalities. Evidence of inflammation was visualized in the intermediate, basal cells and Bowman's membrane. Nerve fibre regeneration was first noted at 12 weeks. Keratocyte activation and hyperreflective extracellular matrix were observed consistently, but by 16 weeks keratocyte activation was diminished, and extracellular matrix resumed normal reflectivity. Cell density in the posterior stroma and endothelium regained preoperative values by 4 weeks, although anterior stroma keratocyte cell density was still reduced by about 10% at 16 weeks. Conclusions: Complete qualitative and quantitative characterization of corneal wound repair was achieved by in vivo confocal laser‐scanning microscopy over 16 weeks following collagen cross‐linking in rabbits. In terms of assessing the ever‐increasing range of cross‐linking protocols, in vivo confocal laser‐scanning microscopy may contribute to minimizing the number of experimental animals, because multiple examinations of the same cases are possible over time.     

Morphological and functional correlations in riboflavin UV A corneal collagen cross‐linking for keratoconus

Purpose: To investigate the correlations between corneal structural modifications assessed by in vivo corneal confocal microscopy with visual function [uncorrected visual acuity (UCVA), best spectacle‐corrected visual acuity (BSCVA)] and morphological data (corneal topography, pachymetry, elevation analysis) after riboflavin UV A corneal collagen cross‐linking (CXL) for the stabilization of progressive keratoconus. Methods: Forty‐four eyes with progressive keratoconus were enrolled in the Siena Eye Cross Study (prospective nonrandomized phase II open trial). All eyes underwent Riboflavin UV A CXL. Preoperative and postoperative evaluation comprised: UCVA, BSCVA, optical pachymetry (Visante OCT, Zeiss, Germany), corneal topography (CSO, Florence, Italy) and tomography (Orbscan IIz; B&L, Rochester, NY, USA) and in vivo confocal microscopy (Heidelberg Retina Tomograph II; Rostock, Heidelberg Gmbh, Germany). Examinations were performed preoperatively 6 months and one day before treatment and at 1, 3, 6 and 12 months of follow‐up. Results: In vivo corneal confocal microscopy showed time‐dependent postoperative epithelial and stromal modifications after cross‐linking. Epithelial thinning associated with stromal oedema and keratocytes apoptosis explained initial tendency towards slightly reduced VA and more glare one month postoperatively in 70% of eyes. Furthermore, a statistically not significant early worsening of topographic mean K values was observed. Orbscan II analysis significantly underestimated pachymetric values after treatment. Pachymetric underestimation was rectified by high‐resolution optical pachymetry provided by the Visante OCT system. After the third post‐CXL month, epithelial thickening, disappearance of oedema and new collagen compaction recorded by in vivo corneal confocal microscopy explained the improvements in visual performance during the follow‐up. Changes in stromal reflectivity and collagen compaction observed by in vivo confocal microscopy were associated with corneal flattening and reduction in anterior elevation values recorded by differential topographic analysis. Conclusion: Corneal structural changes assessed by in vivo corneal confocal microscopy demonstrated significant correlations with visual function (UCVA and BSCVA) and morphological (corneal topography, pachymetry, elevation analysis) findings recorded after riboflavin‐UV A‐induced CXL.     

Conjunctival and corneal findings in bleb‐associated endophthalmitis: an in vivo confocal microscopy study

Purpose: To report the conjunctival and corneal findings in delayed onset glaucoma filtering bleb‐associated endophthalmitis (BAE), by using in vivo confocal microscopy (IVCM). Methods: This was an observational case series. Four eyes of four glaucomatous patients who previously underwent mytomicin C augmented filtering surgery and affected with delayed onset BAE, underwent IVCM of conjunctival bleb and cornea at diagnosis, after 2 and 8 weeks of therapy. The inflammatory status of the conjunctival epithelium and sub‐epithelium was microscopically investigated. Corneal epithelial cells, stromal and endothelial morphology were also evaluated. A group of eight patients with functioning conjunctival filtering bleb was used as control. Results: At diagnosis, a diffuse inflammatory cell infiltration within the conjunctival epithelium presenting evident microcysts was found; conversely, there were no such alterations in the sub‐epithelium. An evident stromal oedema, keratocytes activation and diffuse endothelial inflammatory precipitates were the major corneal hallmarks. After 2 weeks of therapy, besides a remarkable improvement of epithelial inflammation and an evident reduction in endothelial precipitates, dendritic cells appeared within conjunctival sub‐epithelium and corneal epithelium showed aspects of cellular disruption. After 8 weeks, the conjunctival and corneal features consistently improved, except for the endothelium which still presented high‐reflective residual precipitates. Conclusions: In vivo confocal microscopy proved valuable in the analysis of conjunctival bleb and cornea in patients affected with delayed onset BAE, permitting an evaluation of the course of the disease, the response to therapy and the modulation of dose regimen.     

Analysis of COL8A2 Gene Mutation in Japanese Patients with Fuchs’ Endothelial Dystrophy and Posterior Polymorphous Dystrophy

Purpose To determine whether Japanese patients with Fuchs endothelial corneal dystrophy (FECD) and posterior polymorphous dystrophy (PPMD) carry mutations in the COL8A2 gene, and to investigate the possible pathogenicity of the COL8A2 gene in these corneal dystrophies.Methods DNA analysis of the COL8A2 gene was performed in 15 unrelated Japanese patients with FECD, and 5 patients with PPMD using polymerase chain reaction and direct sequencing. Mutation screenings were also performed in 36 unrelated normal volunteers as controls, as well as slit-lamp and specular microscopy.Results Two types of heterozygous missense mutations of the COL8A2 gene (R155Q and T502M) in 5 of 15 FECD probands (R155Q, 3/30 chromosomes, 10.0%; T502M, 3/30 chromosomes, 10.0%) were found. No mutation was detected in the coding region of the COL8A2 gene in the remaining 10 patients with FECD nor in any of the 5 patients with PPMD. These two mutations were also found in normal Japanese volunteers (R155Q, 5/72 chromosomes, 6.9%; T502M, 11/70 chromosomes, 15.7%). The chromosomal frequency of the two mutations was not significant between the patients and normal controls.Conclusions The R155Q and T502M mutations of COL8A2 may not be the causative defect in the Japanese FECD and PPMD patients examined in this study. Jpn J Ophthalmol 2004;48:195–198 © Japanese Ophthalmological Society 2004     

Differential diagnosis of corneal oedema assisted by in vivo confocal microscopy

The purpose of this study was to demonstrate microstructural differences between clinically similar, but aetiologically different, cases of corneal oedema in four subjects. In vivo confocal microscopy highlighted oedema of the basal epithelium, prominent nerve–keratocyte interactions, and typical ‘epithelialization’ of the endothelium in a case of iridocorneal endothelial syndrome; however, a similar microstructural appearance was observed in a case of presumed herpetic disciform keratitis. The latter diagnosis was subsequently revised on this basis. Confocal examination of Fuchs’ endothelial dystrophy demonstrated oedema of the basal epithelium, prominent wing cells, anterior stromal alterations, fibrosis of Descemet’s membrane and a typical ‘strawberry’ appearance of the endothelium. In contrast, in vivo microstructural examination of bilateral keratoconus with hydrops confirmed oedema mainly involving the epithelium and anterior stroma. In vivo confocal microscopy allows the clinician to observe the living cornea at a microstructural level and to better diagnose and differentiate borderline or unusual cases of corneal oedema.     

圆锥角膜行去上皮角膜胶原交联术后角膜微结构的变化

目的：采用共焦显微镜观察进展期圆锥角膜行去上皮角膜胶原交联术后角膜微结构的变化。

方法：选取2016-02/2017-02于我院行上皮角膜胶原交联术治疗的进展期圆锥角膜患者11例15眼,分别于手术前后行共焦显微镜检查,观察角膜微结构变化。

结果：术后早期角膜上皮下神经纤维显著减少或消失; 角膜前基质呈蜂窝状,几乎无典型的角膜基质细胞,术后3mo基质细胞开始出现,术后12mo基质细胞数量几乎恢复到术前水平,但角膜上皮下神经仍稀疏,未达到术前水平; 术后后部角膜基质细胞和内皮细胞大小及形态未受影响。

结论：角膜胶原交联术后角膜微结构发生变化最明显的是上皮下神经纤维和前基质细胞,但随着随诊时间的延长,这种变化呈逐渐减弱趋势。     

Clinicopathologic correlation and genetic analysis in a case of posterior polymorphous corneal dystrophy

PURPOSE: To evaluate the clinical history, histopathology, and genetics of posterior polymorphous corneal dystrophy (PPMD) in a woman with a prominent retrocorneal membrane. DESIGN: Observational case report and genetic analysis of her family, UM:139. METHODS: Records were reviewed from a case and associated family members. The diagnosis of PPMD was based on clinical examination, immunohistochemical staining, electron microscopy, and screening of genetic markers from regions previously reported to be associated with PPMD. RESULTS: Over 17 years, the proband with PPMD had 25 ocular procedures performed for glaucoma, cataract, cornea, retina, and postoperative problems. A prominent retrocorneal membrane grew onto the crystalline lens and intraocular lens (IOL). Histopathology revealed stratified epithelial-like cells on iris from an iridectomy and stratified corneal endothelium on a corneal button. Electron microscopy on the cornea revealed microvilli, tonofilaments, and desmosomes consistent with endothelial transformation, which was confirmed by positive anticytokeratin (CK) AE1/AE3 and CAM 5.2 immunoreactivity. Negative immunoreactivity in epithelium and positive in endothelium with anti-CK 7 supported the diagnosis of PPMD rather than epithelial downgrowth. Multiple relatives were affected with PPMD with apparent autosomal dominant inheritance, but surprisingly, the PPMD, congenital hereditary endothelial dystrophy 1 (CHED1) and CHED2 loci on chromosome 20 and the collagen, type VIII, alpha-2 (COL8A2) gene were excluded by linkage and haplotype analyses. CONCLUSIONS: We are unaware of previous PPMD reports describing the unusual feature of a retrocorneal membrane extending onto the crystalline lens and IOL. In addition, this family suggests another PPMD locus.     

Congenital Corneal Opacities: A Review with a Focus on Genetics

Congenital corneal opacities present in approximately 3/100,000 newborns. Many different disorders may result in corneal opacifications of infancy, including Peters' anomaly (PA), congenital hereditary endothelial dystrophy (CHED), congenital hereditary stromal dystrophy (CHSD) and posterior polymorphous dystrophy (PPMD). Current studies have localized defects using genetic testing in PA, CHED, CHSD and PPMD. Identifying mutations for specific disorders may lead to better understanding of the underlying pathogeneses and may help with diagnosis and prognosis. This article will review the clinical presentations, treatments and genetics of Peters' anomaly, congenital hereditary endothelial dystrophy, congenital hereditary stromal dystrophy and posterior polymorphous dystrophy.     

Dystrophia Smolandiensis: a novel morphological picture of recurrent corneal erosions

Purpose: The aim of this study was to describe morphological changes in Dystrophia Smolandiensis, a corneal disease that is characterized by recurrent corneal erosive episodes and the formation of central corneal keloid‐like opacities in approximately half of those affected. Methods: The corneas of seven affected individuals were examined using in‐vivo confocal microscopy. Specimens of one primary corneal graft, one regraft and one biopsied keloid‐like region – all obtained from members of a large family with the disease – were re‐examined with a light microscope. Sections were stained with Congo red and analysed immunohistochemically for fibronectin and S100A4. Results: Light microscopic examination revealed epithelial hyperplasia, absence of Bowman’s layer and subepithelial fibrosis. Fibronectin was expressed in the area of subepithelial fibrosis, and the keratocytes in this area generally expressed S100A4. The biopsy specimen stained positive for Congo red, suggesting an amyloid deposit. In‐vivo confocal microscopy confirmed epithelial abnormalities, loss of Bowman’s layer and significant alterations of the subbasal nerve plexus in affected individuals. Conclusion: The morphological picture in Dystrophia Smolandiensis is novel for a condition dominated by recurrent corneal erosions at the clinical level. Although no single morphological feature unique to the disease could be found, the general morphological pattern of pathology (true keloid formation, absence of Bowman’s layer, subepithelial fibrosis and abnormal subbasal nerves) probably reflects a novel phenotypic expression of the healing response to recurrent erosion of the corneal epithelium. However, the pathogenesis of Dystrophia Smolandiensis remains to be elucidated fully.     

The significance of Vogt's striae in keratoconus as evaluated by in vivo confocal microscopy

Background: To evaluate the association of the presence, extent and width of Vogt's striae with other microstructural corneal alterations in keratoconus using in vivo confocal microscopy (IVCM). Methods: Sixty‐eight keratoconic corneas of 68 patients were evaluated with slit‐lamp examination (SLE), corneal topography and IVCM. For each eye, the presence, extent and width of alternating light and dark bands (Vogt's striae) observed using IVCM was recorded together with keratocyte and endothelial cell densities, stromal nerve thickness, subbasal nerve density and thickness. The refractive status and the mean and steepest corneal curvatures were noted. Results: Vogt's striae were present in 43 (63.2%) eyes on SLE and dark bands were present in 53 (77.9%) eyes on IVCM. Compared with patients without dark bands, patients with dark bands had significantly higher refractive errors in spherical equivalents (SE; ?8.15 ± 3.70 vs. ?5.18 ± 2.46 diopters [D], P = 0.007), higher astigmatic errors (?5.88 ± 2.69 vs. ?4.10 ± 1.84 D, P = 0.027), higher steepest corneal curvatures (54.33 ± 4.38 vs. 51.23 ± 3.72 D, P = 0.018), lower anterior stromal keratocyte densities (1106 ± 172 vs. 1222 ± 171 cells/mm², P = 0.022) and lower nerve fibre densities (18.74 ± 6.54 vs. 22.66 ± 6.47 nerves/mm², P = 0.054). Compared with patients in whom dark bands were confined to the posterior stroma, patients with dark bands extending into the anterior stroma had significantly higher refractive errors in SE (?11.17 ± 2.25 vs. ?6.34 ± 3.48 D, P < 0.001), higher astigmatic errors (?7.44 ± 2.56 vs. ?4.69 ± 2.22 D, P = 0.006) and wider bands (6.0 ± 2.1 vs. 9.6 ± 3.1 µm, P < 0.001). Conclusions: Vogt's striae appear to be more prevalent in keratoconic corneas than can be appreciated clinically. The presence of Vogt's striae may be associated with corneal topographic and microstructural changes.     

The clinical spectrum between posterior polymorphous dystrophy and iridocorneal endothelial syndromes

BackgroundThere are many conditions affecting the corneal endothelium with similar clinical appearances, though with different prognoses, management approaches, and pathophysiologic development.CaseA 39-year-old black woman with a previous diagnosis of asymmetric corneal posterior polymorphous dystrophy (PPMD) presented complaining of irritation in the left eye, worsening over the last week. On examination, her left eye had profuse edema and bullous keratopathy overlying a large placoid gray lesion at the level of the endothelium. Gonioscopy of the left eye found evidence of a membranous development extending from the endothelium to the trabecular meshwork. Examination of her right eye found a perfectly clear cornea and a normal angle. The patient subsequently had Chandler's syndrome diagnosed in the left eye, an iridocorneal endothelial (ICE) syndrome, rather than PPMD.DiscussionPPMD and ICE syndromes present with many similarities; these clinical entities are in fact thought to be variants of the same disease. Unlike PPMD, Chandler's syndrome is unilateral, acquired, and typically symptomatic and progressive. It also characteristically affects middle-age women.ConclusionUnderstanding the clinical features of PPMD and ICE syndromes is important in proper diagnosis and management.     

Congenital corneal opacities: a review with a focus on genetics

Congenital corneal opacities present in approximately 3/100,000 newborns. Many different disorders may result in corneal opacifications of infancy, including Peters' anomaly (PA), congenital hereditary endothelial dystrophy (CHED), congenital hereditary stromal dystrophy (CHSD) and posterior polymorphous dystrophy (PPMD). Current studies have localized defects using genetic testing in PA, CHED, CHSD and PPMD. Identifying mutations for specific disorders may lead to better understanding of the underlying pathogeneses and may help with diagnosis and prognosis. This article will review the clinical presentations, treatments and genetics of Peters' anomaly, congenital hereditary endothelial dystrophy, congenital hereditary stromal dystrophy and posterior polymorphous dystrophy.     

后部多形性角膜营养不良49例共聚焦显微镜影像学观察

目的:探讨49例后部多形性角膜营养不良(PPCD)患者在共聚焦显微镜(IVCM)下的影像学特征。方法:回顾性病例研究。收集我院2013-01/2021-01诊断为PPCD患者49例86眼,包括男32例,女17例,平均年龄42.5±22.9岁。所有患者均进行IVCM检查,分析角膜内皮细胞密度及不同类型病变的镜下特点。结果:所有患者病灶区内皮细胞数量均较外周细胞数量低。IVCM下病变呈1型囊泡型的有44眼(51%),表现为角膜内皮层的圆形或不规则弹坑样病灶,单个或多个出现;2型条带型16眼(19%),表现为边缘弧形凸起,部分可见似赘疣样影像散在或条索状分布;3型弥漫型26眼(30%),表现为内皮细胞大面积缺失,大部分区域内皮成像不清,呈匍匐样、条索样延展的凸起,成像较清晰处部分同条带型病灶。观察病例中有2例患者随访4～5a, IVCM下病灶均较前有变化,包括中央角膜内皮数量的减少和上皮层铁质沉着等。结论:IVCM能够显示PPCD患者各期内皮细胞和Descemet膜水平的特征性显微结构改变,通过观察其影像学特点可以为疾病提供有效的诊断价值。     

Comparison of in vivo confocal microscopy of human cornea by white light scanning slit and laser scanning systems

PURPOSE: To compare in vivo corneal imaging by scanning slit white light and laser confocal microscopy systems. METHODS: Twenty healthy individuals and 10 patients with corneal dystrophies including Fuchs, granular, Map-Dot-Fingerprint dystrophies, and amiodarone-induced keratopathy were examined with the ConfoScan 3 (Nidek Technologies) scanning slit white light confocal microscope equipped with x40 front lens (Zeiss) and the Rostock Cornea Module (RCM) for HRT II (Heidelberg Engineering) laser confocal microscopy system equipped with Olympus x60 front lens. The endothelial cell density counts were performed and results were compared. For additional validation of endothelial cells density results, separate counts were carried out using the specular microscope SP-1000 (Topcon). RESULTS: The healthy and pathologically changed corneal structures are imaged in a similar manner by both systems. The differences in quality of acquired images in contrast and brightness between the systems are debatable, although the laser system was more efficient for epithelium imaging and white light scanning slit was better for evaluation of endothelium. Some of the examinations completed with the laser system, which requires applanating its front lens to the cornea, imaged dark striae in posterior stroma and Descemet membrane folds, resembling those observed in corneal pathologies, whereas most were probably induced by the pressure applied to the cornea during examination. All the results of cell density (for patients and for subjects with no ophthalmic disease) counts performed with the RCM (laser system) were higher than those with the ConfoScan 3 (scanning slit system) by 36.7% +/- 11.9% (SD) and 30.2% +/- 11.3% higher than SP-1000 (specular). The difference in cell counts between the RCM and other methods was increasing at higher cell densities. CONCLUSIONS: The morphologic findings in examinations performed with the laser confocal microscopy system are generally comparable to white light scanning slit confocal microscopy. Direct applanation of the front lens of the laser system to the cornea may generate certain changes in confocal microscopy outcomes, including imaging of Descemet membrane folds and dark lines in stroma, which should be differentiated from pathologic alterations. Comparison of the endothelium cell density counts obtained with the 2 systems should be made cautiously because significant differences might occur--RCM configured with the Olympus x60 front lens was found to overestimate the results compared with both CS3 and SP-1000 microscopes, with the range of disparity increasing for higher cell densities.     

Clinicopathological features of ocular cystinosis

A 31‐year‐old woman who presented with photophobia was found to have bilateral corneal and conjunctival crystal deposition. Ocular cystinosis was diagnosed upon observation of typical crystals and lack of systemic involvement. In vivo confocal microscopy confirmed crystal deposition of the corneas and conjunctivae bilaterally. Optical coherence tomography showed stromal hyper‐reflectivity due to crystals within the corneal stroma. Transmission electron microscopy of the conjunctiva demonstrated pathognomonic intralysosomal cystine crystals inside fibroblasts and macrophages. Clinicopathological characteristics of ocular cystinosis are well described by this exceptional case.