الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Phacoemulsification has become the treatment of choice for
cataract surgery over the past two decades due to Improvements in
technology and surgical techniques (Dupont-Monod et al., 2009).
The choroid, a highly vascularized structure located between the
lamina fusca of the sclera and the retinal pigment epithelium (RPE), is
an important tissue that supplies blood to the outer retina and is the
source of many vision-threatening diseases, such as choroidal
neovascularization, polypoidal choroidal vasculopathy, central serous
chorioretinopathy, and high myopia–related chorioretinal atrophy
Therefore, studying the choroidal structures is important for
understanding the pathology and mechanisms underlying these critical
diseases ( Ohsugi et al., 2014).
The effects of cataract surgery on the posterior segment of the
eye still understudy. In most cases, phacoemulsification does not
change the macroscopic funduscopic appearance of the retina.
However, novel noninvasive imaging techniques such as crosssectional
imaging of the retina with time domain and spectral domain
optical coherence tomography (SD-OCT) have shown that macular
thickness may increase subclinically after surgery. This subclinical
thickening can be detected in many cases of uneventful surgery, with a
peak occurring 4–6 weeks after surgery. About 6 months after cataract
surgery, macular thickness returns to baseline (von et al., 2007).
Enhanced depth imaging OCT (EDI-OCT) was described by
(Spaide et al.) and (Margolis and Spaide). This new technique
enables the cross-sectional structure and thickness of the choroid to be
evaluated. The subfoveal choroidal thickness (SFCT) is measured
vertically, at the fovea, from the outer surface of the hyperreflective
line ascribed to the retinal pigment epithelium (RPE) to the
hyperreflective line of the inner sclera border. Thanks to this method,
the involvement of the choroid has been highlighted in several
inflammatory pathologies ( Spaide et al.,2008) and( Margolis and
Spaide ., 2009).
This prospective study was carried out on 53 eyes of 53 patients
having cataract selected randomly from patients attending the
ophthalmic outpatient clinic of Menoufia Ophthalmology department
during the period from February 2015 to October 2015. The aim of the
study was to evaluate the potential changes in the SFCT after cataract
surgery, using the EDI-OCT technique, and to determine if the
variations in the SFCT are correlated with the development of PCME.
After history taken, preoperative ophthalmologic examination
was performed including visual acuity measurement, slit lamp
biomicroscopy, tonometry, fundus examination and OCT examination
using the EDI-OCT technique to measure choroidal thickness.
Phacoemulsification using Geuder machine was done for all
cases using the minimal amount of ultrasound power and the minimal
manipulation.
All cases were followed up for 3 months postoperatively. Three
visits were arranged for every case at one week, one month, and 3
months postoperative intervals. In each visit the following were done
for every case:
- Ophthalmic examination.
-OCT examination.
There was statistically significant increase in the mean
choroidal thickness at one week postoperative then the choroidal
thickness start to decrease at one month postoperative to reach near
the baseline value at one month postoperative. The greatest
progression of mean subfoveal choroidal thickness was observed
between 1st and 7th day after surgery.
There was statistically significant increase in the mean macular
thickness at one week postoperative then the mean macular thickness
start to decrease at one month postoperative to reach near the baseline
value at one month postoperative. The greatest progression of mean
macular thickness was observed between 1st and 7th day after surgery.
IOP, axial length and age were the most important risk factors
which affect choroid changes during the postoperative period. During
the early post-operative period, the decrease in IOP leads to increase
the perfusion pressure to the choroid with subsequent increase in
choroidal thickness.
IOP was significantly decreased at the 2nd and 3rd postoperative
follow up than the preoperative level.
There was significant negative correlation between axial length
and choroidal thickness, subfoveal thickness and macular thickness
either pre-operative or postoperative.
In this study, there was a case of pseudophakic cystoid macular
odema (PCME) (1.8%) despite the use of postoperative prophylactic
anti-inflammatory drops. For this patient, no surgical complications
occurred, the duration of the surgery was limited to less than 15
minutes and the amount of ultrasounds delivered was low.
Surprisingly, the highest values of SFCT were observed for this
patient at day7 after surgery, while no cystoid macular edema was
present on the SD-OCT images. The central macular thickness
increased at week6 with a typical image of PCME on SD-OCT, while
the SFCT was still elevated. It seemed that the increase of choroidal
thickness preceded the occurrence of the PCME. These findings raise
questions about the pathophysiological role of the choroid in the
development of PCME.