الفهرس 
Penetrating KeratoplastyOnly 14 pages are availabe for public view
 |  | from | 114 |  |  |
| | | from | 114 | | |
Abstract
Forty eyes of 38 patients with three different underlying
diseases (bullous keratopathy, 7 eyes; corneal scar, 20eyes;
keratoconus, 13 eyes) who performed penetrating keratoplsty in the
period between January 2014 and December 2015 were reviewed
retrospectively at Menofia University among the period of April
2017 to May 2018. We performed AS-OCT for all patients and
classified wound profiles of the graft–host junctions into wellapposed
junction and malapposed including (gap, step, and
protrusion). We analyzed correlations between clinical data and post
PKP wound characteristics from the AS-OCT data.
A total of 320 graft–host junctions from 40 eyes were analyzed.
Among them, 130 sections (40.6 %) had well-apposed junctions and
190 sections (59.4 %) had mal- apposed junctions. The most frequent
type of malapposition was protrusion (97 sections, 30.3 %). When
categorizing the eyes according to the most frequent alignment type
among the 8 cross-sections, the alignment pattern showed highly
significant differences between the preoperative diagnosis groups (P =
0.001). Spherical equivalent (P = 0.001) showed highly significant
differences between the alignment groups. Graft–host thickness
disparities showed no significant correlations with spherical
equivalent (r = -0.184, P \ 0.256).
All patients underwent full ophthalmologic examinations
including best-corrected visual acuity, refraction, slit-lamp biomicroscopy,
intraocular pressure, keratometric astigmatism using a
manual keratometer, and evaluation of the graft–host interface using
a spectral domain AS-OCT of Topcon 3D OCT-2000 device.
Patients included in this study have a preoperative diagnosis of
keratoconus, bullous keratopathy, and corneal scar. Patients excluded
from this study have a history of other combined surgery such as
amniotic membrane transplantation or limbal transplantation, and any
additional surgery due to complications after PKP. We excluded also
patients who had a difficulty in acquiring high-quality images for
them because of incooperation or when it was difficult to obtain
keratometeric values owing to irregular astigmatism.
Surgical technique
Surgery was performed by a single experienced surgeon
(M.S.A.) under either general or retrobulbar anesthesia. The removal
of the sutures was implemented step-by-step over two to four times
within 1 year after surgery.
AS-OCT imaging
Topcon 3D OCT-2000 AS-OCT using spectral-domain
technology was used in this study. After all corneal sutures were
removed, we perform the evaluation. We directed the subjects to look
straight at a fixation target within the device in a sitting position and
a single experienced examiner (H.M.E) scanned four high-resolution
optical sections in the interval of 45° and obtained high resolution
eight images of the graft–host interface.
The examiner interpreted the OCT images. Each image of graft–host
interface was categorized according to alignment patterns of the
corneal internal side as follows:
(a) Well- apposed junction if the corneal internal side was aligned
precisely without disconnection.
(b) Gap if Descemet’s membrane and the inner stroma of the donor
and recipient were not connected, but were aligned.
the anterior chamber.
The central corneal thickness was measured. We calculated the
thickness disparity at the wound interface by drawing an imaginary
line perpendicular to the external and internal sides of the cornea,
from the central point of the line where the donor and recipient met;
and the thickness disparity was calculated by measuring the
thicknesses of the donor and recipient corneas, each at the point that
was 1 mm away from the meeting point on the external side. The
average of the eight calculated absolute values was obtained.
According to the preoperative clinical diagnosis, the patients
were categorized into 3 groups including: (a) corneal scar group, (b)
bullous keratopathy group, and (c) keratoconus group. We evaluated
the distribution of alignment patterns among each diagnosis group.
The eyes were classified into the well-apposed junction and
malapposed junction including gap, step, or protrusion groups
according to the most frequent type among eight wound alignment
patterns in each eye. When the alignment pattern is not frequent , we
categorized it as others. Patient’s age (years) , sex , postoperative
duration (monthes) , best corrected visual acuity (Decimal),
intraocular pressure (mm Hg) , spherical equivalent (diopters) ,
central corneal thickness (micrometer), and thickness disparity
(micrometer) at the wound interface were compared between the
alignment groups.