Search

Purpose To ascertain the effects of aging on corneal morphology and to illustrate the morphologic diversity of the different layers in the normal cornea as seen by in vivo confocal microscopy (IVCM). Design Observational cross-sectional study. Participants A total of 150 healthy subjects, evenly distributed over 5 age categories, comprising 75 men and 75 women. Methods Both transparent corneas (n = 300) of all subjects were examined in duplicate by white light IVCM (Confoscan 4, NIDEK Technologies, Albignasego, Padova, Italy). After reviewing the IVCM examinations for morphologic variations of the corneal layers, we selected the 8 most common features to illustrate the morphologic diversity. Subsequently, all 600 IVCM examinations were assessed for the presence of these features. We used binary logistic regression analyses to assess the age-relatedness of each feature. Main Outcome Measures Age distribution of bright superficial epithelial cells, dendriform cells, alterations characteristic of epithelial basement membrane dystrophy (EBMD), tortuous stromal nerves, stromal microdots in the anterior stroma, folds in the posterior stroma, opacification of Descemet's membrane, and corneal guttae. Results Four features were found characteristic of the aging cornea: stromal microdots in the anterior stroma ( P P P P P = 0.09). Other features, such as bright superficial epithelial cells (n = 38, 13%), dendriform cells (n = 42, 14%), and tortuous stromal nerves (n = 115, 38%), were age-independent. We also found a novel phenotype of corneal endothelium in 4 normal eyes of 2 subjects, which we coined "salt and pepper endothelium." We could not establish whether this novel phenotype represented a morphologic variant of normal endothelium, an early stage of a known corneal endothelial disorder, or a completely new disease entity. Conclusions Knowledge of the common morphologic variations of the corneal layers and the effects of aging on corneal morphology as seen by IVCM increases our understanding of corneal degenerative disorders and is essential to detect corneal pathology. Our finding of a novel phenotype of corneal endothelium emphasizes the morphologic diversity of this optically transparent tissue. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Objective To evaluate the outcome of phototherapeutic keratectomy (PTK) treatment of epithelial basement membrane dystrophy (EBMD) patients and to examine clinical and morphologic signs of recurrent dystrophy. Design Cross-sectional, clinic-based study. Participants Fifty-two eyes of 39 patients diagnosed with EBMD who underwent PTK between 2001 and 2008. Methods Preoperative symptoms, best spectacle-corrected visual acuity (BSCVA), and refraction data were collected. At follow-up, refraction and BSCVA were measured, symptoms were noted, and slit-lamp biomicroscopy and in vivo confocal microscopy (IVCM) were performed. Main Outcome Measures Best spectacle-corrected visual acuity and signs of recurrent EBMD based on symptoms and morphologic features. An assessment of EBMD severity after PTK additionally was considered. Results Mean follow-up time was 43 months (range, 7–100 months). After PTK, BSCVA remained unchanged or improved in 49 (98%) of 51 eyes. Twenty-four (46%) of 52 eyes had recurrence of some form, and recurrence was correlated positively with postoperative time ( P Conclusions Although PTK is an effective method of alleviating the clinical symptoms of EBMD, the dystrophy can recur with time. The relationship between the postoperative development of clinical symptoms and the corneal morphologic features is complex and requires further investigation. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Purpose To describe corneal changes in patients with epithelial basement membrane dystrophy (EBMD) using a new in vivo confocal microscope. Design Observational case series. Methods A retrospective chart review of 22 consecutive patients with EBMD at the Quinze-Vingts National Ophthalmology Hospital from April 2004 to March 2005 was conducted. Gender, age, history of painful episodes suggestive of recurrent erosions, best-corrected visual acuity, slit lamp findings, and in vivo confocal microscopy images were analyzed. Results There were 8 male (36.4%) and 14 female (63.6%) subjects. Eighteen patients (81.2%) had a history of recurrent erosions in 1 or in both eyes. In 37 eyes of 19 patients (86.4%), map and/or dot and/or fingerprint changes were observed biomicroscopically. In 3 patients (13.6%) with recurrent erosions, the cornea had a normal structure on slit lamp examination and the diagnosis of EBMD was made after in vivo confocal microscopy examination. Four patients (18%), despite basement membrane abnormalities, reported no corneal symptoms suggesting recurrent erosions. In vivo confocal microscopy images showed that all patients had an abnormal epithelial basement membrane protruding into the corneal epithelium, epithelial cell abnormalities, and microcysts. No abnormalities were observed in superficial epithelial cells or the stroma. Conclusion Epithelial basement membrane dystrophy is characterized by an abnormal basement membrane protruding toward the epithelium and epithelial microcysts. In vivo confocal microscopy using the HRT II Rostock Cornea Module provides better resolution and therefore outlines distinctively in vivo microstructural characteristics of EBMD. It assists in the diagnosis of EBMD in patients suffering from recurrent erosion syndrome, particularly in patients with no corneal change visible biomicroscopically.

Objective To characterize morphologic changes in corneas of patients with recurrent erosion syndrome or epithelial basement membrane dystrophy using in vivo confocal microscopy. Design Observational case series Participants Fourteen eyes of eight patients with diagnosed epithelial basement membrane dystrophy and 13 eyes of seven patients with recurrent erosion syndrome were examined. Methods Slit-lamp examination and in vivo confocal microscopy. The pathologic findings are presented as digitized images obtained from video tape recorded during the confocal microscopy. Main outcome measures The morphology of corneal surface epithelial cells, basal epithelial cells, subbasal nerve plexus, Bowman's layer, stromal keratocytes, and endothelium was analyzed. Results The surface epithelium was intact in all but two eyes. One cornea (a basement membrane disorder with clinically visible dots) had multinucleate surface epithelial cells, and one eye with recurrent corneal erosions showed a freely floating surface epithelium sheet in the tear fluid. Patients in both groups showed islets of highly reflective cells with presumed intracellular deposits surrounded by normal cells in the basal epithelial cell layer. The basal epithelial cell area also showed other pathologic changes, including drop-shaped configurations, streaks, or ridges. Folding of the Bowman's layer was also observed in both groups. Anterior keratocytes showed signs of activation (highly reflective nuclei with visible processes) in some of the patients regardless of the clinical diagnosis, and in recurrent erosions even increased deposition of abnormal extracellular matrix in the anterior stroma was suspected. Posterior corneal keratocytes and endothelium appeared normal when examined. The subbasal nerve plexus showed various pathologic changes, such as short or strangely shaped nerve fiber bundles, decreased numbers of long nerve fiber bundles, only faintly visible long nerve fiber bundles (instead of the normally observed long parallel running interconnected bundles), or increased amounts of Langerhans cells, but only one patient (with recurrent erosion syndrome) lacked the subbasal nerve plexus. Conclusions In vivo confocal microscopy of corneas with recurrent erosions or epithelial basement membrane dystrophy showed deposits in basal epithelial cells, subbasal microfolds and streaks, damaged subbasal nerves, or altered morphology of the anterior stroma. Confocal microscopy cannot replace biomicroscopy in making a specific diagnosis, but it sometimes helps the diagnosis in corneas that appear normal under a biomicroscope.

Objective This study aimed to describe the morphology of cystic disorders of the corneal epithelium by confocal microscopy. Design The study design was a prospective evaluation of confocal microscopic images of patients with cystic corneal disorders. Participants Thirteen patients (19 eyes) were included. The corneal disorders included four patients with corneal decompensation (Fuchs’ dystrophy), five patients with epithelial basement membrane dystrophy (e.g., Cogan’s microcystic and map-dot dystrophies), one patient with Meesmann’s dystrophy, and three patients with recurrent erosion syndrome of unknown etiology. Confocal images of diseased comeas were compared with those of ten normal control eyes (ten subjects). Intervention All patients were examined by slit-lamp biomicroscopic analysis and confocal microscopic analysis (Tomey, Erlangen-Temmenlohe, Germany). Image analysis was used to identify the corneal epithelial structures correlated with the corresponding pathology. Main outcomes measures Confocal microscopy was used to assess the size, shape, light scatter, and reflection of the cysts. Results Slit-lamp examination results showed corneal epithelial cystic lesions in all cases. Confocal microscopy was able to identify cystic lesions in 9 (69.2%) of 13 patients. Of the four patients in whom lesions could not be found by confocal microscopy, three had recurrent erosion syndrome and the other one had epithelial basement membrane dystrophy. The confocal images were compatible with the clinical and histologic pictures of the disease. Normal control eyes did not show any epithelial lesion, either by biomicroscopy or confocal microscopy. Conclusions Confocal microscopy provides an in vivo evaluation of cystic epithelial corneal lesions. This study shows that confocal microscopy is suitable for examining cystic lesions of the corneal epithelium. Nevertheless, it is not as sensitive as biomicroscopy in detecting cystic lesions in certain corneal conditions.

Purpose To compare the efficacy of phototherapeutic keratectomy (PTK) to epithelial debridement and polishing of Bowman's membrane using a diamond burr (DB) in the treatment of recurrent corneal erosions associated with anterior basement membrane (ABM) dystrophy. Design Retrospective nonrandomized comparative trial. Methods Medical records of 39 patients (42 eyes) who underwent a PTK or DB procedure for recurrent corneal erosions associated with ABM dystrophy between March 1992 and June 2000 were reviewed. History of injury, prior treatment received, and the corneal slit-lamp findings were noted in all patients. In both procedures, all loose epithelium was completely removed. In PTK patients, 5 μm of Bowman's membrane was ablated with the excimer laser. In patients who underwent DB treatment, a hand-held battery-driven diamond dusted burr was used to gently and uniformly polish Bowman's membrane in the area of the epithelial defect. Main outcome measures Symptomatic improvement, recurrence of painful erosions, development of haze, and change in the visual acuity. Statistical analysis was performed for comparison of data between the two groups. Results Fifteen eyes of 14 patients underwent PTK, and 27 eyes of 25 patients underwent epithelial debridement and DB treatment. In the PTK group, mild haze was seen in five (35.7%) eyes. Recurrence of painful erosions was seen in four eyes (26.7%). The mean follow-up was 17.6 ± 5.7 months (range, 0.7–81.9 months). Best-corrected visual acuity was better in five eyes (35.7%) after the procedure and the same in nine eyes (64.3%). In the DB group, mild haze was seen in seven eyes (25.9%). Recurrence of painful erosions was seen in three eyes (11.1%). The mean duration of follow-up was 6.7 months (range, 1–24.2 months). Best-corrected visual acuity was better in 3 eyes (14.3%), the same in 17 eyes (81%), and worse in 1 eye (4.8%) after the procedure. Final visual acuity was not available for one eye in the PTK group and 6 eyes in the DB group. There was no statistically significant difference in haze (Fisher's exact test, P = 0.38), recurrence of erosions (Kaplan-Meier analysis with log rank, P = 0.73), and vision being better or the same (Fisher's exact test, P = 0.6) between the PTK and DB groups. Conclusions Both PTK and DB treatment are effective methods of treating recurrent corneal erosions associated with ABM dystrophy. Diamond burr treatment, being a simpler, less expensive office procedure with a tendency toward lesser incidence of haze and recurrence in this study, seems to have advantages over PTK in the treatment of recurrent corneal erosions. Further prospective studies are required to confirm the long-term efficacy of DB treatment in the management of recurrent corneal erosions associated with ABM dystrophy.

Subendothelial blebs were seen in cases of superficial keratopathy of varied etiology: superficial punctate keratopathy (42 patients); keratoconjunctivitis sicca (11 patients); epithelial basement membrane dystrophy (9 patients); mild superficial keratopathy due to exposure (9 patients), trichiasis (6 patients), or chemical contact (4 patients); and in contact-lens wearers (29 patients). The blebs were probably due to intercellular edema, separating endothelial cells from Descemet's membrane, and were reversible after resolution of the keratopathy. If the condition is chronic, changes in endothelial morphology may occur, with pleomorphism and polymegathism of the endothelial cells. These cases show that conditions which cause fine disruption of the corneal epithelium affect the integrity of the corneal endothelium. Recognition of resulting long-term changes may be important before intraocular surgery or if the cornea is to be used for grafting.

Corneal epithelial opacities similar to those seen in corneal epithelial basement membrane dystrophy were seen in 33 of 71 eyes following radial keratotomy. These changes were clinically indistinguishable from those seen in map-fingerprint-dot dystrophy with map type changes seen most often. Basement membrane changes tended to be transient (persisting less than 3 months in 75.3% of eyes) and not usually visually significant. However, three eyes had changes which persisted for 12 months. Most eyes with basement membrane changes had involvement of less than one-half quadrant of the corneal (68%). Involvement of two or more quadrants occurred in 9.4% of eyes with these changes. One eye had visually significant changes which persisted for 3 months. There were no episodes of recurrent erosion.