Localized conjunctival extra-nodal marginal zone B cell lymphoma with presumed Paraproteinic Crystalline Keratopathy.

Crystalline corneal deposits have been well reported in individual cases of lymphoproliferative disorders associated with hyper-gammaglobulinemia, hence called 'Crystalline Paraproteinemic Keratopathy'. This is the first report of corneal deposits in a case of localised conjunctival B-cell Lymphoma without paraproteinaemia/hyper-gammaglobulinemia, hence called 'Presumed Paraproteinic Crystalline Keratopathy'.

In vivo confocal microscopic findings in patients with limbal stem cell deficiency.

AIM: To describe in vivo confocal microscopy (IVCM) findings in patients with limbal stem cell deficiency (LSCD). METHODS: 23 eyes of 17 consecutive patients suffering from LSCD were included in this study. A detailed examination by IVCM was performed in addition to a routine slit-lamp biomicroscopy. Size and density of corneal epithelial and conjunctival epithelial cells on cornea were measured and statistically analysed using SPSS version 8.0 software. Results were compared with histology in select cases. RESULTS: Anatomical and morphological differences were observed between normal corneal cells and conjunctival epithelial cells on cornea. Size and density differences reached statistically significant levels between the normal corneal cells and the conjunctival epithelial cells on cornea (p<0.01). Goblet cells were visible throughout the conjunctivalised corneal epithelium in eight eyes. Several IVCM features could be correlated with histology in six of our patients. CONCLUSIONS: A number of features were demonstrated by laser IVCM in patients presenting clinically with LSCD. Some of these features were corroborated with features observed on histological examination of tissue samples.

Histological and confocal microscopy changes in chronic corneal edema: implications for endothelial transplantation.

PURPOSE: To report in vivo confocal microscopic (IVCM) features in corneal edema supported by histopathologic correlation. METHODS: This was an observational study with evaluation of diagnostic technology. Twenty patients with clinically diagnosed corneal edema were involved, including 11 with Fuchs' endothelial dystrophy (FED). All cases, in addition to a control group of six normal eyes, were examined with IVCM before keratoplasty. Four eyes were examined after surgery. Thirteen corneal samples obtained by penetrating keratoplasty were examined by light and/or electron microscopy. IVCM and histopathologic sections were then analyzed for correlation and proper interpretation. Seven patients underwent Descemet's stripping endothelial keratoplasty (DSEK). RESULTS: Subepithelial fibroblasts were seen histologically and with IVCM in 7 (53.8%) of 13 full-thickness corneal samples. IVCM alone detected these changes in 11 (55%) subjects before surgery, as well as after postoperative clinical improvement. Other IVCM features included absent (30%) or reduced (70%) subbasal corneal nerves, expanded hyperreflective keratocyte cell bodies, and processes with small vacuoles and large extracellular lacunae (95%), seen on IVCM only. Endothelial changes with polymegathism and reduced cell density were seen in non-FED cases. CONCLUSIONS: This is the first study in which IVCM features of corneal edema have been compared in detail with histopathologic findings. Subepithelial fibroblasts, reduced subbasal corneal nerves, and stromal keratocyte morphology were well documented in this study. With increasing popularity of DSEK this work supports the role of IVCM in quantitative evaluation of corneal edema in early preoperative stages, as well as after surgery, when the cornea appear clinically, but not histologically, normal.

Corneal nerve aberrations in bullous keratopathy.

PURPOSE: To study the corneal nerves in patients with chronic bullous keratopathy. DESIGN: Prospective observational case series with histologic evaluation. METHODS: We studied 25 eyes of 25 bullous keratopathy patients of different etiologies (17 female, 8 male; mean age, 76.3 years) as well as 6 eyes of 6 normal control subjects (5 male, 1 female; mean age, 38 years). All subjects were scanned by laser scanning confocal microscope. Five corneal buttons obtained following penetrating keratoplasty from 5 of the above patients and 6 normal control corneal buttons were stained as whole mounts with acetylcholinesterase (AChE) method for corneal nerve demonstration and scanned in multiple layers with digital pathology scanning microscope. RESULTS: The density, branching pattern, and diameter of sub-basal nerves were significantly lower in corneas with bullous keratopathy compared with normal corneas (density: 4.42 ± 1.91 mm/mm(2) vs 20.05 ± 4.24 mm/mm(2); branching pattern: 36.02% ± 26.57% vs 70.79% ± 10.53%; diameter: 3.07 ± 0.64 µm vs 4.57 ± 1.12 µm). Aberrations such as localized thickenings or excrescences, abnormal twisting, coiling, and looping of the (mid) stromal nerves were observed in the study group both by in vivo confocal microscopy and on histology. CONCLUSIONS: Striking alterations in corneal innervation are present in corneas with bullous keratopathy that are unrelated to any specific etiology of bullous keratopathy. This study provides histologic confirmation of novel in vivo confocal microscopy findings related to corneal nerves in bullous keratopathy.

Corneal intraepithelial neoplasia: in vivo confocal microscopic study with histopathologic correlation.

PURPOSE: To ascertain in vivo confocal microscopic features of corneal/conjunctival intraepithelial neoplasia (CIN) and correlate these with histology of the same lesions. DESIGN: Observational case series with evaluation of diagnostic technology. METHODS: Four patients with unilateral CIN (3 men and 1 woman) were examined with the Heidelberg Retina Tomograph II (HRT II) Rostock Cornea Module (RCM) confocal microscope before, during, and after treatment. Corneal epithelial samples were taken by alcohol delamination technique in 2 patients, while impression cytology (IC) samples were obtained in the other 2 patients. Morphometric analysis of confocal and histologic images was carried out and the findings correlated. Four controls (all men, 2 with limbal stem cell deficiency, 1 with a limbal lesion, and 1 with diffuse keratoconjunctival proliferation) were similarly examined. Two of these had biopsy for histologic examination. Main outcome measures comprised the degree of correlation between histology and confocal microscopic features of CIN. RESULTS: Dysplastic cellular changes were noticed on histopathology and correlated well with confocal microscopy, corresponding to the different corneal epithelial layers. Bright nucleoli within huge nuclei and ill-defined cell borders were a feature of the basal epithelium on histopathology and confocal microscopy. Subbasal corneal nerves were not visualized on confocal microscopy in areas affected by CIN. These features disappeared in response to treatment cycles as the basal epithelium reverted to its normal pattern, as seen by confocal microscopy. CONCLUSION: Confocal microscopy findings highly correlate with histologic features in CIN. Confocal microscopic features of CIN as defined in this study will enable a reliable diagnosis in a noninvasive manner. Confocal microscopy will also allow real-time monitoring of the condition during treatment.

Ex vivo confocal microscopy of human corneal nerves.

AIMS: To evaluate the distribution, morphometry and the postmortem changes of the central and peripheral human corneal nerves by exvivo laser-scanning confocal microscopy (EVCM). METHODS: 24 eyes from 14 cadavers were retrieved at different time intervals after death and examined by EVCM. Five regions were examined in each eye: central, superior, inferior, temporal and nasal. In each region, corneal nerve images were categorised according to their anatomical location in the cornea into sub-basal, stromal and limbal nerves. Five nerve parameters were measured: density, orientation, diameter, numbers and branching pattern. RESULTS: Exvivo confocal scanning of a motionless eye allows high quality imaging and tracking of corneal and limbal nerves. Stromal nerves from the sub-Bowman's plexus perforate the Bowman's zone and terminate in bulb-like structures, from each of which a leash of sub-basal nerves arises. Following death, sub-basal nerve parameters showed significant changes. The density decreased from 9.23+/-4.48 to 0.45+/-0.07 mm/mm(2), the diameter from 4.01+/-0.81 to 2.08+/-0.20 microm, the numbers from 8.3 to 1.0 and branching pattern from 39.38% to 0% (p<0.05) from day 1 to day 5 postmortem. Stromal and limbal nerves showed no significant changes in their density and diameter. CONCLUSIONS: This study establishes a direct link between sub-basal nerves and the sub-Bowman's nerves via distinct terminal bulbs. Limbal nerves are the thickest, are seen in all quadrants and can be traced to the corneal centre. The sub-basal nerve plexus rapidly degenerates after death but stromal and limbal nerves survive during the first five days after death.

Histologic features of transplanted amniotic membrane: implications for corneal wound healing.

PURPOSE: To evaluate the histologic changes occurring in the transplanted amniotic membrane in human eyes. DESIGN: Observational consecutive case series. PARTICIPANTS: Seven consecutive patients who underwent amniotic membrane transplantation (AMT) for bullous keratopathy and subsequently had a penetrating keratoplasty (PK). METHODS: Corneal buttons obtained at PK were examined by light and electron microscopy and by immunohistology with antibodies against CD34 (keratocytes), alpha smooth muscle actin and vimentin (myofibroblasts and fibroblasts respectively). Time from AMT to PK ranged from 2 to 32 months. MAIN OUTCOME MEASURES: Immunophenotypic characteristics of cells populating transplanted amniotic stroma. RESULTS: Amniotic tissue was covered with stratified corneal epithelium with well-defined desmosomes and hemidesmosomes. Transformed corneal stroma-derived cells (CSDCs) could be seen migrating from the anterior stroma, through breaks in the Bowman's zone, into connective tissue of the amniotic membrane. Immunohistology showed that the cells populating amniotic stroma were CD34 negative but positive for vimentin and alpha smooth muscle actin. In 2 samples in which corneal transplants were performed approximately 1 year or more after AMT, some cells in the amniotic stroma showed CD34+ staining. Features of increased metabolic activity and formation of new collagen were seen on electron microscopy. In 2 cases, epithelial cell nests were seen in the amniotic stroma. CONCLUSIONS: The amniotic basement membrane facilitates epithelial cell migration and adhesion. The amniotic stroma supports CSDCs and epithelial cells. Repopulation of the amniotic stroma by CSDCs migrating through breaks in Bowman's zone integrates the amnion with corneal tissue and allows for rebuilding of corneal stroma. Over time, some CSDCs may revert to the resting keratocyte immunophenotype.

The role of limbal stem cells in corneal epithelial maintenance: testing the dogma.

OBJECTIVE: To study and characterize the epithelial cells in patients with a central "island" of normal epithelial cells surrounded with 360 degrees of clinically apparent limbal stem cell (SC) deficiency with conjunctivalization of the limbus and peripheral cornea. DESIGN: Observational, prospective, consecutive case series. PARTICIPANTS: Five human subjects (8 eyes) who presented with total limbal SC deficiency in 1 or both eyes with a central area of normal corneal epithelial cells. METHODS: Clinical slit-lamp examination, aided with fluorescein staining, for evidence of conjunctivalization and in vivo confocal microscopy (IVCM) of the conjunctivalized limbus and peripheral cornea and the normal central corneal epithelium. MAIN OUTCOME MEASURE: Long term survival of normal stratified corneal epithelial cell sheet in the presence of total limbal SC deficiency. RESULTS: In all 8 eyes the diagnosis of limbal SC deficiency was confirmed by clinical and IVCM examination. The conjunctivalized area extended circumferentially along the entire limbus, seen clinically by the presence of fluorescein staining cells, epithelial irregularity, and vascularization and by IVCM showing bright conjunctival epithelial cells, superficial and deep blood vessels, and goblet cells. The central corneal epithelial cells had a normal appearance with polygonal superficial cells, well-defined wing cells, and smaller basal cells. The central "islands" of normal epithelial cells remained unchanged over the mean follow-up period of 60 months (range, 8-12 years). CONCLUSIONS: The existence and survival of a healthy sheet of corneal epithelial cells over the follow-up period, in the presence of clinically apparent total limbal SC deficiency, suggests a limited role of limbal epithelial SC in physiologic homeostasis of the corneal epithelium. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed on this article.