en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background:</span></span></span></span></span></span> <span lang="en-GB" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:black"><span style="language:en-GB">Cataract surgery requires accurate prediction of the effective lens position (ELP) to optimize refractive outcomes. Both axial length (AL) and prior ocular tissue changes, including radiotherapy exposure, can influence postoperative results.&nbsp;</span></span></span></span></span></span></span></span></span></span><span lang="en-GB" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold">Materials and Methods: </span></span></span></span><span lang="en-GB" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;">This longitudinal study included 285 patients (312 eyes) undergoing phacoemulsification with intraocular lens implantation. Among them, 27 patients (29 eyes) had a documented history of orbital or periocular radiotherapy, delivered with external beam therapy (median cumulative dose 45 Gy, range 30-60 Gy) for ocular adnexal or head and neck malignancies. Preoperative AL was measured using partial coherence interferometry, and postoperative ELP was determined via anterior segment optical coherence tomography (AS-OCT). Refractive error and best-corrected visual acuity were evaluated at 1, 3, 6, and 12 months. Statistical analyses were performed using SPSS with bivariate correlation and subgroup comparisons.&nbsp;</span><span lang="en-GB" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold">Results: </span></span></span></span><span lang="en-GB" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;">Short AL eyes (<22.0 mm) demonstrated a mean ELP of 4.50 mm (SD &plusmn; 0.35), while long AL eyes (>24.5 mm) had a shallower mean ELP of 4.00 mm (SD &plusmn; 0.40) (p < 0.001). Eyes with prior radiotherapy exhibited a significant posterior displacement of the ELP (mean reduction 0.18 mm, p = 0.042) and a higher incidence of hyperopic shift. Despite overall visual improvement across all groups, radiotherapy-treated and long AL eyes showed greater refractive variability, with slower stabilization within &plusmn;0.4 D. </span><span lang="en-GB" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold">Conclusion: </span></span></span></span><span lang="en-GB" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;">Both axial length and prior radiotherapy independently affect postoperative ELP and refractive predictability. Careful surgical planning is essential in these high-risk groups to optimize visual outcomes.</span></div> Axial length, cataract extraction, lens implantation, intraocular, radiotherapy. 221 227 http://ijrr.com/browse.php?a_code=A-10-1-1479&slc_lang=en&sid=1 Z. Zhang 7900319475328460032966 7900319475328460032966 No Department of Cataract Specialist, Lanzhou Purui Ophthalmology Hospital, Lanzhou, Gansu Province, China