Basement Membrane Dystrophy Research Articles

Increased Matrix Metalloproteinase-2 and Matrix Metalloproteinase-3 Concentrations in Corneal Epithelium of Patients with Recurrent Corneal Erosions.

Purpose To assess the role of selected matrix metalloproteinases in defective corneal re-epithelization in patients with recurrent corneal erosions. Subjects The study group (group 1) included patients with recurrent corneal erosions qualified for phototherapeutic keratectomy. The group 1 was divided into two subgroups regarding the etiology of recurrent corneal erosions: group 1A, Cogan's basement membrane dystrophy, and group 1B, trauma. The control group (group 2) included patients with healthy eyes qualified for Epi-Bowman Keratectomy. Methods The analyzed material was the corneal epithelium collected during phototherapeutic keratectomy or Epi-Bowman Keratectomy in the study or control group, respectively. Matrix metalloproteinases concentration was determined by an immunohistochemical method using Human Magnetic Luminex® Assay. Results The study revealed a statistically significantly higher concentration of matrix metalloproteinase-2 in group 1 compared to the control and a statistically significantly higher concentration of matrix metalloproteinase-3 in group 1 compared to the control. Conclusions The results obtained in the study can prove that matrix metalloproteinase-2 and matrix metalloproteinase-3 having the ability to dissolve anchoring fibers and the corneal epithelial basement membrane could be responsible for epithelial instability and their accumulation in the corneal epithelium may induce recurrence of erosion.

Histological Studies on Ageing Changes in the Cornea of Indian Buffaloes (Bubalus bubalis)

Background: Affections of eye commonly encountered in all the species of animals. If these not treated in time, the vision may be hampered, this may impair the physical ability, utility and productivity of animals leading to economic loss to the animal owners. Corneal dystrophies like basement membrane dystrophy, stromal dystrophy, endothelial dystrophy, corneal erosions and corneal ulcerations etc., seen in the aged buffaloes. The current study was carried out to establish basic data and to provide authentic information to the clinicians on ageing changes in eyes of buffaloes. Methods: The study on age related changes in the cornea was conducted on 63 eye balls of locally available buffaloes of different breeds in and around Proddatur. These buffaloes were categorized into 3 groups based on their age i.e., group I (1-5 yrs), group II (6-10 yrs) and group III (11 yrs and above) buffaloes. The eyeballs were isolated and fixed with Davidson’s fluid. The paraffin sections of cornea were subjected for routine histological study. Result: The mean total thickness (µm) of cornea was increased from group I to III animals and it was 747.22±13.57, 853.33±11.05 and 897.22±8.06. Hence, The mean thickness (µm) of all five layers of cornea increased with advancement of age. Superficial corneal epithelial layer was made up of non keratinized stratified squamous epithelium with 6 to 7 layers at early age and 12-14 layers of cells in adult animals. The mean thickness (µm) of corneal epithelium in group I to III animals was 117.04±3.37, 122.59±2.23 and 133.71±3.55 respectively. Bowman’s membrane of cornea was measured 12.97±0.86, 17.22±0.55 and 18.71±0.68 in group I, II and III animals respectively. The mean thickness (µm) of corneal stroma in group I to III animals was 600.75±10.33, 672.22±10.46 and 690.00±5.32 respectively. This was mainly due to progressive increase in number of collagenous lamellae. The keratocytes became thin in old animals. Thickness of posterior band zone (PBZ) of Descemet’s membrane was increased with advancement of age. The mean thickness (µm) of Descemet’s membrane and endothelium together was in group I, II and III animals was 16.48±0.91, 41.29±2.25 and 54.82±1.44 respectively. The corneal endothelial cells were enlarged and increased in size in old buffaloes. The age related pigmentation was also noticed in epithelium and stroma of cornea in animals of group III. Density of sub basal nerve plexuses between the stroma and the corneal epithelium was not altered with advancement of age.

A Convolutional Neural Network Classifier VGG-19 Architecture for Lesion Detection and Grading in Diabetic Retinopathy Based on Deep Learning

Diabetic Retinopathy (DR) is a type of disease in eyes as a result of a diabetic condition that ends up damaging the retina, leading to blindness or loss of vision. Morphological and physiological retinal variations involving slowdown of blood flow in the retina, elevation of leukocyte cohesion, basement membrane dystrophy, and decline of pericyte cells, develop. As DR in its initial stage has no symptoms, early detection and automated diagnosis can prevent further visual damage. In this research, using a Deep Neural Network (DNN), segmentation methods are proposed to detect the retinal defects such as exudates, hemorrhages, microaneurysms from digital fundus images and then the conditions are classified accurately to identify the grades as mild, moderate, severe, no PDR, PDR in DR. Initially, saliency detection is applied on color images to detect maximum salient foreground objects from the background. Next, structure tensor is applied powerfully to enhance the local patterns of edge elements and intensity changes that occur on edges of the object. Finally, active contours approximation is performed using gradient descent to segment the lesions from the images. Afterwards, the output images from the proposed segmentation process are subjected to evaluate the ratio between the total contour area and the total true contour arc length to label the classes as mild, moderate, severe, No PDR and PDR. Based on the computed ratio obtained from segmented images, the severity levels were identified. Meanwhile, statistical parameters like the mean and the standard deviation of pixel intensities, mean of hue, saturation and deviation clustering, are estimated through K-means, which are computed as features from the output images of the proposed segmentation process. Using these derived feature sets as input to the classifier, the classification of DR was performed. Finally, a VGG-19 deep neural network was trained and tested using the derived feature sets from the KAGGLE fundus image dataset containing 35,126 images in total. The VGG-19 is trained with features extracted from 20,000 images and tested with features extracted from 5,000 images to achieve a sensitivity of 82% and an accuracy of 96%. The proposed system was able to label and classify DR grades automatically.

Clinical features of Streptococcus pyogenes keratitis: Case series

PurposeTo characterize the risk factors, clinical presentations, management, outcomes, and microbiological properties of Streptococcus pyogenes keratitis. MethodsEight culture-proven cases (eight eyes) of S. pyogenes keratitis were diagnosed and treated between 2008 and 2018 at the University of Pittsburgh Medical Center (UPMC). Medical records were available for six patients, and these were reviewed to identify demographic information, systemic and ocular history, clinical presentations, antibiotic sensitivity, treatments, and outcomes of S. pyogenes isolates. ResultsOf the six charts reviewed, the median patient age was 67 years and all patients were female. Four patients had a history of cataract extraction more than one year prior to presentation, one had a history of improper contact lens use, and one had basement membrane dystrophy. Two patients, who also happened to have the most serious medical comorbidities, presented with corneal perforation on initial examination. The median follow-up length was 90.5 days. Visual outcomes varied greatly between patients. Three patients had visual acuity ranging from 20/30 to 20/70, while the two patients with corneal perforation had a final visual acuity of light perception, and one patient was lost to follow-up. Five of six isolates were susceptible to fluoroquinolones and all isolates were susceptible to cefazolin. ConclusionsS. pyogenes represented an uncommon ocular pathogen at UPMC eye clinic. However, if left untreated, this infection resulted in severe ocular morbidity. The majority of patients had a benign ocular history, suggesting that S. pyogenes can infect healthy corneas in immunocompetent patients. The majority of isolates were susceptible to cefazolin and fluoroquinolones.

A CARE-compliant article: optical coherence tomography for epithelial basement membrane dystrophy

Rationale:The etiology of anterior corneal opacities and the effect of debridement cannot be determined by biomicroscopy. Optical coherence tomography (OCT) helps identify the character and depth of these lesions.Patient concerns:A 45-year-old female complained of progressive blurred vision for a long time. Slit lamp biomicroscopy showed irregular, faint scar-like opacity of anterior cornea in her both eyes. Pentacam Scheimpflug camera tomography showed irregular astigmatism of anterior corneal surface. Anterior segment spectral-domain OCT revealed thickened, hyper-reflective linings, and scattered lesions, mainly in the epithelial layer.Diagnoses:Epithelial basement membrane dystrophy (EBMD).Intervention:Epithelial debridement and bandage lenses.Outcomes:The cornea became clear and the vision improved soon after debridement. The pathology showed thickened aberrant basement membrane extending into mid-epithelial layer, with microcyst-like lesions also noted.Lessons:OCT defines the depth of lesions and helps diagnosis and management of EBMD.

Recurrent corneal erosion: a comprehensive review.

PurposeTo comprehensively review the literature regarding recurrent corneal erosion (RCE) and to present treatment options and recommendations for management.OverviewRCE usually presents with sharp, unilateral pain upon awakening, in an eye with an underlying basement membrane dystrophy, prior ocular trauma, stromal dystrophy or degeneration, or prior surgery for refractive errors, cataracts, or corneal transplantation. Making the correct diagnosis requires a careful slit-lamp examination of both eyes coupled with a high degree of suspicion. Several treatments are commonly used for RCE but new therapies have been introduced recently. Conservative treatment consists of antibiotic and preservative-free lubricating drops, with topical cycloplegics and oral analgesics to control pain. Patients who are unresponsive to these therapies may benefit from therapeutic bandage contact lenses (BCL). Newer therapies include oral matrix metalloproteinase (MMP) inhibitors, blood-derived eye drops, amniotic membrane graft application, and judicious application of topical corticosteroids. Once the epithelium is healed, a course of hypertonic saline solution and/or ointment can be used. Surgical procedures may be performed in patients who fail conservative therapy. Punctal occlusion with plugs increases the tear film volume. Epithelial debridement with diamond burr polishing (DBP), anterior stromal puncture (ASP), or alcohol delamination should be considered in selected patients. DBP can be used for patients with basement membrane dystrophies and is the preferred treatment overall due to a low recurrence rate. ASP can be used for erosions outside the central visual axis. Excimer laser phototherapeutic keratectomy is an attractive option in eyes with central RCE since it precisely removes tissue while preserving corneal transparency. In patients with RCE who are also candidates for refractive surgery, photorefractive keratectomy can be considered.SummaryNewly introduced therapies for RCE enable therapy to be individualized and lower the recurrence rate.

Diamond burr superficial keratectomy in the treatment of visually-significant anterior corneal lesions

To evaluate the efficacy and safety of diamond burr superficial keratectomy in the treatment of visually-significant anterior corneal lesions. A retrospective review of 23 eyes (23 patients). Pre- and postoperative visual acuities and refractions, slit-lamp biomicroscopic findings, and the incidence of recurrence of disease after keratectomy were studied. Nineteen eyes had map-dot-fingerprint basement membrane dystrophy and 4 had Salzmann's nodular degeneration. All patients presented with decreased vision, as well as varying degrees of glare, halos, and monocular diplopia. Postoperative follow-up ranged from 3 to 39 months (mean 10.6 months), and no recurrence of the original disease occurred within this period. This procedure improved the best-corrected visual acuity from 20/36 (LogMar 0.250) to 20/24 (LogMar 0.076) by LogMar statistical evaluation (p<0.001) and caused a statistically non-significant (p=0.232) myopic change in the mean refractive spherical equivalent (-0.36 diopter +/- SD 2.28 preoperatively to -0.71 +/- 2.26 postoperatively). Glare and monocular diplopia were subjectively reduced or eliminated in all patients. One patient had mild anterior stromal haze which decreased the bestcorrected visual acuity from 20/25 to 20/30. Diamond burr superficial keratectomy appears to be an effective and safe method of removing visually-significant anterior corneal opacities.

Making a difference in recurrent erosion syndrome

One of my favorite diagnoses is recurrent ero-sion syndrome (RES) since patients withrecurrent erosions are some of the most satis-fying (for the patient an d for me) to treat. Themajority of patients I see with RES havealready been accurately diagnosed by theirreferring doctor. Patients typically have theclassic symptoms of foreign body sensation orfrank eye pain occurring suddenly in the mid-dle of the night or upon awakening in themorning. The pain can last from seconds tominutes to hours, depending on the amountof corneal epithelial disruption. Patients oftenhave obvious anterior basement membranedystrophy (ABMD) in the affected eye or ahistory of corneal trauma, most commonlyfrom a fingernail, tree branch or paper edge.Much less commonly, patients may also have areadily apparent corneal problem, such asReis-Bucklers or lattice corneal dystrophy, as areason for their erosions.Some patients have a less revealing historyand few prominent clinical findings. Occa-sionally, patients may not recall the cornealtrauma initially and may need to be askedspecifically about any ocular injury. Addi-tionally, the traumatic incident may not beall that recent. On slit lamp examination, thefindings can be quite subtle. Mild ABMDchanges are often best appreciated by using awide slit beam angled from the side. Fluores-cein dye may reveal areas of mild negativestaining, highlighting regions of ABMD orareas of recent epithelial loosening. Usingretroillumination through a dilated pupil,faint epithelial irregularities may becomemore apparent. Careful examination of thefellow eye may also demonstrate ABMDchanges.Once the diagnosis is made (or highly sus-pected), I discuss the condition and treatmentoptions with the patient