الفهرس 
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Abstract
Myopia or short sightedness is the most common eye disease, responsible for nearly 33 % of defective vision. Myopia is increasing globally, with the most rise in frequency in the young generations in East and Southeast Asia. It causes a huge burden on countries economy due to macular and retinal complications.
Myopia is a spherical refractive error in which the point of conjugate focus in the retina is displaced anteriorly in front of the eye, when no accommodation is taking place. Another definition is the refractive condition where parallel light rays originating from an object at optical infinity are focused by the eye in front of the retina through relaxed accommodation. The most common presentation is blurred distance vision, so it is called ”nearsightedness.”
We classified myopia into 2 groups :
A) Non Pathological or Simple myope with refraction <-6SD
B) Pathological myope groupe with refraction > -6SD.
There are many risk factors that may increase the development of myopia of which like positive family history, appearance of myopia using retinoscopy in infants with no cyclopegic effect, emmetropic children with refractive error +0.50 D, accommodation power is decreased or near point esophoria, excessive time spent on near work on a regular basis, when corneal curvature is steep or axial length is high compared to corneal radius ratio more than 3.00, circumstances temporarily preventing the retina from seeing clear image during infancy.
Clinical Picture
The most noticeable complaint of uncorrected myopia is indistinct far distance vision then asthenopia through time.
Also the primary sign discovered by the doctor in diagnosing myopia is decreased unaided far visual acuity, that can be treated with standard or near-standard levels with the right minus power lens.
Pathological myopia is typically congenital or of early onset high myopia. Complete correction of visual acuity may be not be fully corrected due to pathological complications in the posterior segment.
The most unsafe common complication of pathological myopia is myopic retinopathy, which is a main cause of irreversible vision loss and even blindness.
The causes of myopic retinopathy development are not all clearly understood but may be because massive axial elongation, retinal thinning and choroidal thinning, and weak the sclera.
Myopic retinopathy mainly presented by the lacquer cracks presence, posterior staphylo;2ma, myopic choroidal neovascularization, myopic macular hole, macular retinoschesis and atrophy of the chorioretinal junction in the posterior fundus.
Optical coherence tomography (OCT) is now considered a very valuable addition to the diagnostic ophthalmic investigation departement. It is a noninvasive, noncontact office-based imaging procedure which enable cross-sectional images of the posterior retina corresponding to slices of histology, but in living patients.
This study included 60 myopic eyes. Ages ranging from 20 to 70 years old. They were divided according to refraction into low myopia less than or equal -6SD (30 patients 15 females and 6 males) and high myopia more than -6SD (30 patients12 females and 7 males).
Inclusion Criteria:
1- Age between twenty and seventy years old.
2- Normal cornea (no ectasia, no leucoma, no ulcer).
3- Normal or myopic fundus.
4- Simple and pathological myopia.
Exclusion Criteria:
1- Patients with dense media opacity.
2- Patients who had any ocular surgery in the same eye.
3- Patients with any ocular disease.
4- Patients with systemic diseases as diabetes mellitus or toxoplasmosis.
5- Patients taking any ophthalmic eye drops, ointments or injections.
Data was collected from patients included age, past ocular and medical history, medications, allergies, and family history of eye diseases. best corrected visual acuity, dilated fundus examination with +20 D Volk lens.
Every patient was subjected to IOL master 500 to measure axial length and Heidelberg OCT to examine the macula.
The interpretation records include:
• Age and sex.
• Refraction.
• BCVA.
• Axial Length
• CMT
• Myopic complications ex. myopic contour, thinning of RPE, presence of CNV or macular hole
The results obtained were tabulated & statistically analyzed using specific analytical program.
The study have meet the ethical standards that have been stated stated by the faculty of Medicine- Ain Shams University with taking a written and verbal informed consent .
This study revealed a highly significant negative correlation between axial length and subjective refraction. Thus, we can conclude that as the axial length increased the more highly negative spherical equivalent required for correction. There was no significant findings including myopic macular complication in low myopic group with respect to sex, mean age with the mean CMT was 255.5 ±17.13.
There was significant findings including macular complications in high myopia, where the mean CMT was 262.10 ±67.51, the mean CNV was positive in 5 patients (16.7%), the mean Macular Hole was 1 patient (3.3%), Thinning of RPE was 10 (33.3), Myopic Contour was 30 (100 %).
There was no significant correlation between refractive errors and CMT.
There was no correlation between central macular thickness and axial length.
As in our thesis showed that the longer the axial length, the more possible to have complications like CNV. There were 5 high myopic eyes with axial length > 27.5 mm with CNV, 4 of them were female and 1 male. So CNV is more common with long axial length and females.
Myopia is an underestimated eye disease. It is recommended to have an annual screening programs in school to identify children with refractive errors. Educating the parents about the important of correcting the refractive error as it may affect the health and the learning curve of their children. Special attention should be given to individuals with risk factors of developing myopic complications especially high myopes like CNV or macular hole by doing regular examination and follow up by taking OCT images preferable on the same device.
To avoid myopic complications resulting from high myopia, we should early screen to diagnose it and early treatment if found or even suspected are the key in treating high myopia complications.