الفهرس 
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Abstract
Keratoconus is a degenerative, non-inflammatory disorder characterized
by progressive corneal thinning and protrusion, leading to irregular myopic
astigmatism and impairment of visual function. Keratoconus is a bilateral
condition in most cases, though presentation may be asymmetric. The incidence
of keratoconus ranges from 50 to 230 per 100,000 per year across different
populations. The onset of keratoconus is generally during puberty, with a
variable amount of progression, which may last until third or fourth decade of
life. Typical patient with keratoconus complains of blurring or distortion of
vision and decrease in visual acuity, photophobia, monocular diplopia, visual
distortion, asthenopia and glare around lights, keratoconus should be suspected
in any young adult with irregular astigmatism, or in any patient with myopic
astigmatism whose spectacle prescription is changing more frequently than
normal. Retinoscopy usually shows irregular myopic astigmatism. A scissoring
reflex and an oil-droplet reflex (Charleux sign) are highly suggestive of
keratoconus. On slit-lamp examination prominent corneal nerves should
prompt search for other signs of keratoconus, Subepithelial and anterior stromal
scars may be present secondary to breaks in Bowman’s membrane. Vogt striae
are fine parallel lines seen in the posterior stroma Fleischer ’s ring found around
the base of the cone. Clinical signs in advanced keratoconus include Munson
sign, Acute hydrops. The aim of this study is to evaluate the results of deep
anterior lamellar keratoplasty in cases with keratoconus. This study is
Prospective non comparative case study. 30 Patients were selected from the out
patient clinic of the National Eye Center, between January 2014 and June 2014.
All patients were subjected to preoperative evaluation which included: Full
history as age, gender, family history, history of any eye diseases. Clinical
examination as preoperative best corrected visual acuity, careful slit lamp
examination to detect the signs and severity of keratoconus. Investigations as
pentacam to detect the grade of keratoconus. After diagnosis of keratoconus the
patient signed consent for intervention. All patients undergone deep anterior lamellar keratoplasty operation. Preferred anathesia for this operation is general
anathesia. Periodical follow up for 12 months after the surgery was done.
Postoperative data included: Best corrected visual acuity, corneal graft clarity.
from our study it was found that moderate to sever cases of keratoconus
without affection of the DM and endothelium are the best indication for deep
anterior lamellar keratoplasty. The visual outcome after DALK in keratoconus
patients is very good. The best corrected visual acuity in 89% of cases in this
study is better than or equal to 6/24 after 1 year of post operative follow up.
DALK technique is difficult and the operation takes longer time than PKP, but
the learning curve of the technique is satisfactory. The main advantage of
DALK is absence of endothelial rejection which is the main cause of corneal
graft failure in PKP operations. The most common intra operative complication
of DALK is Descemet′s membrane micro perforation, In this study 8 patients
(26.67%) developed micro perforation of Descemet′s membrane, when this
complication occurs it needs proper intra operative management by injecting air
in the anterior chamber of the eye and do proper dissection of corneal stroma
until reaching Descemet′s membrane so we have no need to convert to
penetrating keratoplasty and we maintain the benefits of DALK and avoid the
complications of PKP. The common post operative complications are interface
haze and debris in this study 5 cases (16.67%) showed interface haze and 3
cases showed interface debris (10%) which decreased by time and nearly
disappeared after 1 year of follow up.In this study the DM detachment occurred
in 4 cases (13.33%) which needs injection of air in the anterior chamber in the
second day after the operation. The epithelial and stromal rejection happened in
6 cases in the early period after the operation and needs treatment with topical
steroid which reverse the rejection episode. The suture loosing occurred in 4
cases (13.33%) and need re suturing in the early period after the operation.