POSTOPERATIVE REFRACTIVE SURPRISES FOLLOWING CATARACT SURGERY: A COMPREHENSIVE REVIEW ARTICLE

Modern cataract surgery is judged by its refractive result. A postoperative refractive surprise, usually defined as a spherical equivalent more than 1.0 diopter (D) from the intended target, remains one of the leading causes of patient dissatisfaction. Although contemporary biometry and intraocular lens (IOL) power formulas allow roughly 70 to 90 percent of eyes to land within 0.5 D of target in large series, a persistent minority of eyes miss the target for reasons that are often identifiable and sometimes preventable. This narrative review summarizes the sources of refractive prediction error along the full surgical pathway: preoperative measurement of axial length, corneal power and anterior segment dimensions; the mathematical and optical assumptions embedded in IOL power formulas; patient-specific situations that violate those assumptions, such as prior corneal refractive surgery, keratoconus and extremes of axial length; IOL-related factors including effective lens position, tilt, decentration, toric misalignment and lens mislabeling; and surgical and postoperative events such as surgically induced astigmatism, capsular contraction and macular edema. We then outline a stepwise diagnostic approach to an unexpected refractive result and compare the available corrective options, mainly spectacles or contact lenses, laser refractive correction, IOL exchange, piggyback IOL implantation, IOL repositioning or rotation, and light-adjustable lenses, with attention to timing, predictability and risk. Finally, we discuss preventive strategies, including dual-device biometry, formula selection by eye type, personalization of lens constants, intraoperative aberrometry, and structured patient counseling. A systematic, protocol-driven approach can reduce the incidence of refractive surprises and make their management faster and safer.