---

Background: Myopia is the most common refractive defect and degenerative myopia is one of the five causes of blindness in the world. The aim of this study is to examine degenerative myopia and its related risk factors. Materials and Methods: In this cross-sectional study, the data was collected through a questionnaire along with the auto-refraction apparatus, which was utilized for determining the myopic degree. The inclusion criteria for this study were the age above the 10, myopia or astigmatic myopia, apparent media (in fonduscopic examination), and the absence of age related retinal defect. Results: A total 65 patients participated in this study 51% of whom had degenerative myopia. Choroid neovascularization was observed in 17.65% of the subjects. There was a significant difference in the relationship between hypertension(r=28%), diabetes mellitus (r =22%) and glaucoma, and degenerative myopia however, this difference was not observed between cataract and myopia. The correlation coefficients between hypertension and diabetes mellitus, and degenerative myopia were 28% and 22%, respectively. This correlation was very low in the case of glaucoma. The greatest correlation existed between the myopic crescent and hypertension (r=0.295%). In all of the cases, the correlation coefficient between diabetes mellitus and all the myopic complications was positive but below 40%. Conclusion: The majority of the patients had degenerative myopia. Hypertension and diabetes mellitus were the most common co-existing diseases. Noticing the correlation coefficient existing between hypertension and myopia, the need for controlling hypertension and diabetes mellitus for preventing retinal complications is emphasized. Also, for preventing the adverse effects of degenerative myopia in retinal defects, controlling glaucoma is suggested.

---

Background: For calculating intraocular lens (IOL) power required for cataract surgery, ultrasonic biometry is used and the axial length of the eye is the most important error in this estimation. Therefore, the aim of this study is to evaluate the final refractive power based on the axis length of the eye in patients undergoing phacoemulsification cataract surgery.

Materials and Methods: In this cross-sectional study, from June 2010 till December 2011, 446 eyes which underwent phacoemulsification cataract surgery were investigated. Biometry was performed before cataract surgery to achieve emmetropia in all eyes. Based on the axis length of the eye, patients were classified into four groups: less than 22 mm, 22-24.5 mm, 24.5-26 mm, and more than 26 mm.

Results: There was not a significant difference in mean absolute value of final refractive power deviation from zero. The highest amount of mean absolute value of final refractive power deviation from zero was in myopia group which was equal to 1.52±1.17 diopter. However, there was not a significant difference in the amounts of mean absolute value of final refractive power deviation from zero according to axial length of the eye (p=0.081).

Conclusion: With increases in axial length of the eye, intraocular lens power calculation decreases, but the absolute difference of means is not significant in two apparatuses.