Articoli Scientifici di Oftalmologia
Argomento : 2
An Accurate Method to Determine Bowman’s Layer Thickness In Vivo in the Human Cornea
PURPOSE.
To determine an accurate value for Bowman’s layer
(BL) thickness in vivo in humans.
METHODS. Seventeen corneal transplant patients were examined
preoperatively by laser-scanning in vivo confocal microscopy
(IVCM), and corneal buttons were removed postoperatively
and sectioned for light microscopy (LM). Nine
corneas with uniformly thick BL by LM were used for thickness
measurement.
In the uniformly thick samples, probable
overestimation of BL thickness in vivo by a first in vivo method
(Method 1) led to the development of a revised in vivo method
(Method 2). Method 2 was used to measure BL thickness in 20
healthy volunteers.
RESULTS. In nine patients, mean BL thickness prior to
transplantation was 13.7 6 1.6 lm by IVCM (Method 1) while
BL thickness of the removed corneal button was 9.7 6 1.7 lm
by LM (P < 0.001). The correlation of BL thickness between
IVCM (Method 1) and LM was poor (P ¼ 0.226). In 20 right
eyes of 20 normal corneas, both in vivo methods were used to
determine BL thickness.
Mean BL thickness by Method 1 was
13.2 6 1.6
lm and by Method 2 was 9.1 6 1.4 lm (P < 0.001).
BL thickness measurements by both in vivo methods were
highly correlated (P < 0.001).
CONCLUSION. BL thickness by a revised in vivo method was
close to LM values in this study and to values reported in
fixed tissue in other studies.
The authors believe this revised
method provides the most accurate estimates of BL thickness
in vivo to date. (Invest Ophthalmol Vis Sci. 2012;53:2354–
2359) DOI:10.1167/iovs.11-8565