Purpose
To define and characterize a novel pre-Descemet's layer in the human cornea.
Design
Clinical and experimental study.
Participants
We included 31 human donor sclerocorneal discs, including 6 controls (mean age, 77.7
years).
Methods
Air was injected into the stroma of donor whole globes (n = 4) and sclerocorneal discs
(n = 21) as in the clinical deep anterior lamellar keratoplasty procedure with the
big bubble (BB) technique. The following experiments were performed: (1) creation
of BB followed by peeling of the Descemet's membrane (DM); (2) peeling off of the
DM followed by creation of the BB, and (3) creation of the BB and continued inflation
until the bubble popped to measure the popping pressure. Tissue obtained from these
experiments was subjected to histologic examination.
Main Outcome Measures
Demonstration of a novel pre-Descemet's layer (Dua's layer) in the human cornea.
Results
Three types of BB were obtained. Type-1, is a well-circumscribed, central dome–shaped
elevation up to 8.5 mm in diameter (n = 14). Type-2, is a thin-walled, large BB of
maximum 10.5 mm diameter, which always started at the periphery, enlarging centrally
to form a large BB (n = 5), and a mixed type (n = 3). With type-1 BB, unlike type-2
BB, it was possible to peel off DM completely without deflating the BB, indicating
the presence of an additional layer of tissue. A type-1 BB could be created after
first peeling off the DM (n = 5), confirming that DM was not essential to create a
type-1 BB. The popping pressure was 1.45 bar and 0.6 bar for type-1 BB and type-2
BB, respectively. Histology confirmed that the cleavage occurred beyond the last row
of keratocytes. This layer was acellular, measured 10.15±3.6 microns composed of 5
to 8 lamellae of predominantly type-1 collagen bundles arranged in transverse, longitudinal,
and oblique directions.
Conclusions
There exists a novel, well-defined, acellular, strong layer in the pre-Descemet's
cornea. This separates along the last row of keratocytes in most cases performed with
the BB technique. Its recognition will have considerable impact on posterior corneal
surgery and the understanding of corneal biomechanics and posterior corneal pathology
such as acute hydrops, Descematocele and pre-Descemet's dystrophies.
Financial Disclosure(s)
The authors have no proprietary or commercial interest in any materials discussed
in this article.
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Article Info
Publication History
Published online: May 28, 2013
Accepted:
January 10,
2013
Received in revised form:
December 7,
2012
Received:
August 21,
2012
Footnotes
Manuscript no. 2012-1293.
Financial Disclosures: The authors have no commercial or proprietary interest in any materials discussed in this article.
Supported by the Elizabeth C. King Trust .
Identification
Copyright
© 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.
ScienceDirect
Access this article on ScienceDirectLinked Article
- Re: Dua et al.: Human corneal anatomy redefined: a novel pre-Descemet layer (Dua's layer) (Ophthalmology 2013;120:1778–85)OphthalmologyVol. 121Issue 5
- In BriefWe read the recent claim of the discovery of a new corneal layer by Dua et al with incredulity.1 The existence of pre-Descemet stromal tissue remaining after pneumodissection is well known. Their further investigation of this pre-Descemet stroma confirms that it is stroma, and not a new corneal layer.
- Full-Text
- In Brief
