الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
One of the most common refractive surgeries is radial keratotomy, sometimes known as RK. The goal of this procedure is to alter the refractive power of the eye, hence decreasing or eliminating the need for corrective lenses or spectacles to treat nearsightedness. With the advent of laser refractive surgeries, which are characterized by higher accuracy and consistency, the radial keratotomy correction has suffered a substantial fall in popularity. However, due to the huge number of patients who have previously had this therapy, familiarity with the method and its modifications is required for dealing with this group of patients who may need visual rehabilitation in the future.
Cataract removal surgery is on the rise because more and more people who have previously had refractive lens exchange are developing cataracts. The necessity for cataract surgery in this demographic, with the same stringent requirements as for refractive surgery patients, is one obstacle they must overcome. Many people believe that phacoemulsification surgery is the best way to get rid of cataracts. Using the standard formulas for determining IOL power in biometry will lead to an incorrect estimate of the total corneal power and effective lens location. Normal corneal curvature is altered by RK, breaking the connection between the front and back of the eye, hence these ideas are flawed. Standard keratometry also measures the region that marks the transition between the incised cornea and the indirectly flattened central zone after RK, which is larger than the optical zone. In addition to this, a hyperopic shift will follow. Due to these challenges, it may be difficult to calculate IOL power using the standard IOL calculation formulas.
Nine alternative formulae were used to forecast the refraction of post-RK eyes, and their outcomes were compared in terms of mean arithmetic refraction prediction error, absolute mean error, and the proportion of eyes that fell within the range of 0.50 D, 1.00 D, and 2.00 D. We focused on eyes with a mean error of 0.50 diopters or less and an absolute mean error of 1 diopter or more. We found no statistically significant differences in the nine different IOL power calculation methods, although we did discover that the Holladay DK, Barrett true K, Haigis, and Hoffer Q formulas were the most accurate. On the other hand, outcomes from earlier generation formulas like SRK II, SRK T, and Holladay 1 were less than ideal. Statistically significant results were found for the absolute mean error for the 26 mm and >26 mm AL subgroups in the SRK T, SRK II, Holladay 1, and Holladay 2 formulas (p0.05). These outcomes also applied to the SRK T and SRK II formulations, as well as the Holladay 1 and 2 versions. The 26 AL group had far better results.