الفهرس 
Patients and MethodsOnly 14 pages are availabe for public view
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Abstract
During cataract surgery several mechanisms may lead to
endothelial injury, including direct trauma from instruments,
ultrasound energy from phacoemulsification, and irrigation fluid
turbulence. Despite the use of viscoelastics, corneal edema is one of
the commonest complications after cataract extraction, affecting
approximately 10% of patients.
Corneal thickness is a sensitive indicator of the health of the
cornea and serves as an index for corneal hydration and metabolism. It
is an important indicator of patency of the corneal endothelial pump.
Despite the need for contact with the cornea, ultrasonic
pachymetry is still at the forefront of the techniques used to obtain
rapid, accurate and reproducible measurements of corneal thickness at
a reasonable cost, when compared with other currently available
devices. Portability of ultrasonic pachymeters allows their use outside
the clinical environment, making them excellent tools for screening
and field data acquisition.
The disadvantages of ultrasonic pachymeter include being a
contact technique with potential drawback of causing discomfort to
the patient and introducing measurement error secondary to the
probe misplacement or corneal compression, Moreover this procedure
requires topical anesthesia which can modify central corneal thickness
values.
This is a prospective study to evaluate the use of Ultrasonic
Pachymetry to compare the changes in central corneal thickness in
patients undergoing Cataract surgery.
The study included fifty patients undergoing cataract surgery at
Department of Ophthalmology, Menoufia University Hospital.
The patients were divided into two groups:
Group (1): 25 patients that underwent Phacoemulsification
Group (2): 25 patients that underwent ECCE (Extra capsular
cataract extraction)
The first CCT measure is taken before discharging the patient
from the hospital and 3 follow-up visits are scheduled (Day7, Day14
and Day21).
Statistical analysis was done after collecting the desired number
of patients (25 patients in each group) and the results were tabulated
and discussed.
There’s a statistically significant difference between the two
groups regarding age and preoperative visual acuity (P<0.05). There’s
no statistically significant difference between the two groups regarding
sex, preoperative IOP readings and preoperative CCT. The Phaco group
(group-1) patients had postoperative corneal edema that was evident
by the CCT that increased from 546.64 ± 49.95 μm preoperatively to
627.52 ± 66.93 at postoperative Day-1 (P <0.05). The edema resolved
and the CCT returned to the preoperative range after 1 week only
(558.92 ± 52.97, P <0.05). The ECCE group (group -2) patients also had
postoperative corneal edema that was evident by the CCT that
increased from 537.12 ± 41.01 μm preoperatively to 682.88 ± 68.85 at
postoperative Day-1 (P <0.05). The edema took longer time to resolve
compared to the Phaco group and the CCT remained significantly
higher than the preoperative levels at week-1 (602.68 ± 71.50, P <0.05)
and week-2 (585.96 ± 49.37, P <0.05) measurements to –finally- reach
the preoperative range after 3 week postoperatively (538.20 ± 41.13, P
>0.05).
from this study we concluded that Ultrasonic pachymeter is a
reliable instrument that is portable and can obtain rapid, accurate and
reproducible measurements of corneal thickness at a reasonable cost,
when compared with other currently available devices. In short term
follow up, post-operative corneal edema after Phacoemulsification
cataract surgery offers faster recovery compared to that after extra
capsular cataract extraction.