الفهرس 
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Abstract
Anophthalmia (anophthalmos) is a developmental eye disorders that
means one or both eyes didn’t form during the early stages of pregnancy.
There are three groups of patients with this condition Primary anophthalmia, Secondary anophthalmia and Degenerative anophthalmia.
Microphthalmia is a developmental eye disorders resulting in smallness of one or both eyes with a total axial length at least 2 standard deviations below the mean for that age group. The eye is considered microphthalmic if the total axial length (TAL) is less than 15 mm at birth. The microphthalmic eye has an axial length less than 19.2 mm at 1 year of age. It arises alone or in conjunction with other ocular defects such as coloboma and orbital cyst. It may be also part of more generalized syndromes.
Classification of microphthalmia varies according to anatomical, clinical or etiological aspects with further subdivisions in each type of classification.The main classification of microphthalmia is according to the anatomic appearance of the globe and the severity of the axial length reduction which includes: severe, simple (or pure) and complex (or complicated) microphthalmia.
Nanophthalmos (simple microphthalmia) describes a congenitally small eye in absence of other major ocular malformations with TAL less than 18 mm, high hyperopia (≥8 diopters), a relatively large lens/globe volume ratio.
Complex microphthalmia refers to a condition in which there are associated abnormalities in the form of either anterior segment dysgenesis
and/or posterior segment dysgenesis with decrease in TAL that can be mild, moderate, or severe.
Microphthalmia with cyst is a form of colobomatous microphthalmia sometimes known as ”congenital cystic eye” present with progressive swelling from birth. This ocular defect is caused by failure of late closure of optic fissure during the emberyonic development.
Other clinical classification for microphthalmia is that of partial microphthalmos which is subdivided into micro anterior segment (relative anterior microphthalmos) when the overall axial length may be normal or even increased, and micro posterior segment (posterior microphthalmos) since each of these may have a different underlying etiology.
In posterior microphthalmos, we describe dispropotionaly small posterior segment and normal dimensions of the anterior segment which is the rarest form of microphthalmia syndrome ,also high hyperopia, elevated papillomacular retinal fold are the main findings in such patients, but the term of relative anterior microphthalmos (RAM) is used to describe the eye with a normal TAL but disproportionately smaller anterior segment with horizontal corneal diameter <11 mm, TAL>20 mm, and an anterior chamber (AC) depth around 2 mm, shallow AC is due to normal sized iris lens diaphragm with a high incidence of glaucoma.
Other classification of microphthalmia can be according to the cause which is either environmental that includes prenatal exposures of mother to intrauterine infections most commonly TORCH infections, heritable (genetic) type (syndromic microphthalmia), or unknown (idiopathic) cause.
Diagnosis of microphthalmia is either prenatal or postnatal and usually based upon clinical and imaging criteria. Also establishing a specific cause this involves undertaking of a comprehensive medical history, physical examination, family history, karyotyping and molecular genetic testing, imaging, and complete systemic evaluation.
The antenatal identification of an abnormal fetus can be through chromosome analysis which is possible upon amniotic fluid fetal cells analysis or on chorionic villus sampling specimens or imaging through fetal ultrasonography that can detect microphthalmia by early second trimester also the three-dimensional (3D) and four-dimensional ultrasound examination may be used in some centers to detect complex malformations of the face, included with anophthalmia and microphthalmia in adition to the MRI which may be useful as an adjunctive to ultrasound examination in detection of anophthalmia.
The postnatal diagnosis can be achieved through clinical diagnosis by the ophthalmologist and imaging techniques as the ultrasound on which the diagnosis of microphthalmia is based and other associated abnormalities can be detected. Computerized tomography (CT) and magnetic resonance imaging (MRI) scans facilitate the diagnosis of microphthalmia and anophthalmia, as the scans show the absence of a globe within the orbit although soft amorphous tissue may be noticed.
The therapy aims at maximizing the existing vision and enhancing the cosmetic appearances rather than improving sight and the main concern in surgical management is for microphthalmia with a cyst either through aspiration of the cyst, removal or conservative management.
Treatment of complications that cause visual impairment in microphthalmos includes treatment of cataract which needs a special
formula for IOL power calculation, because small errors in axial length measurement can lead to large errors in refraction.
Other complications that should be managed are glaucoma, which has a great incidence especially in nanophthalmos. It is proved that glaucoma in nanophthalmic eyes has been treated with laser iridoplasty, surgical iridectomy, filtration surgery, cataract extractions and vortex vein decompression.