Separation of Corneal Stroma and Descemet's Membrane During Deep Lamellar Keratoplasty

Cornea ◽  
2002 ◽  
Vol 21 (2) ◽  
pp. 196-199 ◽  
Author(s):  
Koji Hirano ◽  
Juntaro Sugita ◽  
Miya Kobayashi
Keyword(s):  
Corneal Stroma ◽  
Lamellar Keratoplasty ◽  
Descemet's Membrane ◽  
Deep Lamellar Keratoplasty ◽  
Descemet’S Membrane

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

2021 ◽  
Author(s):  
A. Prasanth Babu ◽  
P. Jagapathi Ramayya ◽  
Y. Nagamalleswari ◽  
Makkena Sreenu ◽  
K. Lakshmi Kavitha
Keyword(s):  
Corneal Epithelium ◽  
Corneal Stroma ◽  
Economic Loss ◽  
Progressive Increase ◽  
Group Iii ◽  
Age Related ◽  
Group I ◽  
Descemet's Membrane ◽  
Descemet’S Membrane ◽  
The Mean

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.

scholarly journals Benzalkonium chloride corneal toxicity post-cataract surgery

2020 ◽  
Vol 17 (1) ◽  
pp. 56-60
Author(s):  
Keith Ong ◽  
Leonard Ong
Keyword(s):  
Cataract Surgery ◽  
Benzalkonium Chloride ◽  
Corneal Stroma ◽  
Eye Drops ◽  
Descemet's Membrane ◽  
Corneal Toxicity ◽  
Descemet’S Membrane ◽  
Free Steroid

Two patients with presumed benzalkonium chloride (BAK) corneal toxicity after routine cataract surgery are presented. Patient 1 had corneal stroma and Descemet’s membrane folds. Patient 2 had moderate superficial punctate epithelial erosions (SPEE). They were on Chlorsig, Maxidex, and Acular eye drops tds postoperatively. The corneas of these two patients improved when BAK was removed or minimized from the postoperative eye drop regimen. Two vials of 1 ml dexamethasone 4mg/ml for injection were added to Chlorsig 10 ml bottle to substitute for Maxidex eye drops. BAK toxicity should be suspected when the cornea is not as clear as expected postoperatively. A practical way to eliminate BAK from postoperative eye drops is described, and would be useful until pharmaceuticals mass-produce BAK-free steroid eye drops economically.

Descemet’s Membrane Detachment

2013 ◽  
Author(s):  
Malik Y. Kahook
Keyword(s):  
Surgical Intervention ◽  
Corneal Stroma ◽  
Corneal Edema ◽  
Glaucoma Surgery ◽  
Bullous Keratopathy ◽  
Descemet’S Membrane Detachment ◽  
Descemet's Membrane ◽  
Central Regions ◽  
Descemet’S Membrane ◽  
Mechanical Manipulation

Corneal injury resulting from glaucoma surgery has been well described. Causes of injury can range from direct mechanical manipulation to the often more subtle pharmacologically induced injuries that occur with use of antifibrotic medications. Descemet’s membrane detachment (DMD) occurs uncommonly during or after intraocular surgery and has been linked with a variety of procedures ranging from simple clear cornea cataract extraction to deep lamellar keratoplasty. The corneal endothelium, which rests upon Descemet’s membrane, functions as a pump to keep the stroma from becoming swollen. Therefore, DMD results in focal corneal edema and possibly bullous keratopathy. If detachment of Descemet’s membrane extends far enough centrally, visual acuity may become sufficiently compromised to necessitate corneal transplantation surgery (either full-thickness penetrating keratoplasty [PKP] or Descemet’s stripping with automated endothelial keratoplasty [DSAEK]). In glaucoma surgery, DMD often results from the mechanical manipulation that occurs with creation of the cornealtrabecular meshwork opening. Knowing how to accurately diagnose and treat DMD can prevent disastrous consequences and preserve vision. Mackool and Holtz proposed separating DMD into 2 categories, planar and nonplanar, depending on the distance of separation between Descemet’s membrane and the posterior corneal stroma. Planar DMD involves less than 1 mm separation of Descemet’s membrane from the corneal stroma and may be limited to the periphery or extend from the periphery to central regions. Nonplanar DMD involves greater than 1 mm separation of Descemet’s membrane from the corneal stroma and may also be categorized as limited to the periphery or extending to central regions. The significance of this classification was the belief that planar DMD was more likely to spontaneously resolve while nonplanar DMD required surgical intervention. Assia and colleagues also split DMD into 2 categories: DMD with scrolling of tissue and DMD without scrolling of tissue. They believed this classification more accurately described potential for spontaneous resolution in that nonscrolled DMD was more likely to resolve without surgical intervention, even if its location was >1mm from the posterior corneal stroma. While useful as a general guide, these classification systems are not foolproof, and each case of DMD should be viewed independently.

scholarly journals The spatial organization of Descemet's membrane-associated type IV collagen in the avian cornea.

1990 ◽  
Vol 110 (4) ◽  
pp. 1457-1468 ◽  
Author(s):  
J M Fitch ◽  
D E Birk ◽  
C Linsenmayer ◽  
T F Linsenmayer
Keyword(s):  
Immunoelectron Microscopy ◽  
Corneal Endothelium ◽  
Spatial Organization ◽  
Type Iv Collagen ◽  
Amorphous Material ◽  
Corneal Stroma ◽  
Spatial Arrangement ◽  
Type Iv ◽  
Descemet's Membrane ◽  
Descemet’S Membrane

The organization of type IV collagen in the unconventional basement membrane of the corneal endothelium (Descemet's membrane) was investigated in developing chicken embryos using anti-collagen mAbs. Both immunofluorescence histochemistry and immunoelectron microscopy were performed. In mature embryos (greater than 15 d of development), the type IV collagen of Descemet's membrane was present as an array of discrete aggregates of amorphous material at the interface between Descemet's membrane and the posterior corneal stroma. Immunoreactivity for type IV collagen was also observed in the posterior corneal stroma as irregular plaques of material with a morphology similar to that of the Descemet's membrane-associated aggregates. This arrangement of Descemet's membrane-associated type IV collagen developed from a subendothelial mat of type IV collagen-containing material. This mat, in which type IV collagen-specific immunoreactivity was always discontinuous, first appeared at the time a confluent endothelium was established, well before the onset of Descemet's membrane formation. Immunoelectron microscopy of mature corneas revealed that the characteristic nodal matrix of Descemet's membrane itself was unreactive for type IV collagen, but was penetrated at intervals by projections of type IV collagen-containing material. These projections frequently appeared to contact cell processes from the underlying corneal endothelium. This spatial arrangement of type IV collagen suggests that it serves to suture the corneal endothelium/Descemet's membrane to the dense interfacial matrix of the posterior stroma.

Sign in / Sign up

Export Citation Format

Share Document