الفهرس 
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Abstract
Myopia is a very prevalent condition. In many developed countries, complications related to high myopia are a major cause of blindness. It has been shown in histopathological studies that there is increasing scleral and retinal thinning with myopia. In myopic eyes, the globe is enlarged with increase in axial length and the stretching beyond normal dimensions may result in thinning of the retina.
Optical coherence tomography (OCT) is a non-invasive technology that provides in vivo high-resolution measurements of the retina, nerve fiber layer, and optic disc. OCT is a valuable new clinical tool that is emerging as highly useful in the diagnosis and monitoring of diseases such as diabetic retinopathy and glaucoma. Increasingly, it is also being used to study the effects of refractive error and elongation of the globe on retinal parameters.
Many studies in the past showed significant variability of relation between macular thickness and different degrees of myopia.
This study aimed to measure the macular thickness by optical coherence tomography in different degrees of myopia and find the correlation between them.
This study was conducted at Rod El-Farag Eye institute. A total of 40 cases were used. They were divided according to their spherical equivalent into 4 groups; emmetropics, low, moderate and high myopes. They all are subjected to automated refraction, correction of vision, slit lamp and fundus examination, Goldennman applanation tonometer for intraocular pressure (IOP) measurement and macular mapping by Spectral-domain optical coherence tomography (SD-OCT) scan.
This study shows the correlation between the degrees of myopia and macular thickness quadrants. The spherical equivalent used for subjective refraction showed the only Negative correlation with the Foveal thickness, it means as the spherical equivalent increases (became less negative) the foveal thickness decrease. It shows a highly statistically significance at the foveal thickness (P= 0.001).
There is fair positive correlation at the parafoveal superior and shows a statistically significance with the spherical equivalent (P= 0.022). In contrast, there is No correlation with the thicknesses at the parafoveal inferior, parafoveal nasal and parafoveal temporal, which shows No statistically significance at them (P= 0.225 & 0.094 &0.085 respectively).
On the other hand, there was a strong positive correlation in perifoveal superior, perifoveal inferior and perifoveal temporal quadrants. It shows highly significant statistically correlation in All four perifoveal quadrants (P-values ranging from 0.006 to < 0.001). This means that in these quadrants as the spherical equivalent increased (became less negative the perifoveal thickness increased.