Refractive Enhancements After Cataract Surgery

Key Points

• There can be several contributing factors to a refractive surprise after cataract surgery, such as incorrect intraocular lens (IOL) calculations as a result of keratometry and/or axial length measurements, postrefractive surgery eyes, or toric IOL rotation (see Chapter 31 ).

• Steps that can be taken to correct postoperative refractive surprises beyond spectacle/contact lens correction include laser vision correction (LASIK/PRK), piggyback lens, IOL exchange, or corneal relaxing incisions (see Chapter 31 ).

• Things to consider when deciding to pursue refractive enhancement include why the error occurred, the patient’s symptoms and goals, and the amount of refractive error needing to be corrected.

Introduction

Refractive surprise after uncomplicated cataract surgery can be daunting. In one large European multicenter database study, refractive outcomes were within 0.50 D for 73% of patients and within 1.0 D for 93%. Although rare, when refractive surprises > 1.0 D occur, patients may be symptomatic and require surgical correction. It is important to consider all factors contributing to the patients’ postoperative refractive outcome when trying to determine the next best step. Careful analysis of biometry data, especially keratometry and axial length, prior refractive surgery history, and examination of the patient can clue the surgeon into potential sources of error. Based on the amount of refractive error, corneal versus lens-based surgery can be pursued.

Causes

It is important to analyze keratometry and biometry measurements because significant errors in these could lead to large refractive surprises . If picked up preoperatively, many of these can be treated or accounted for to allow for a more predictive refractive outcome.

Factors Confounding Keratometry Measurements

• Ocular surface/dry eye disease

• Epithelial basement membrane dystrophy (EBMD) ( Fig. 56.1 )

  

• Corneal opacities: scars or Salzmann nodular degeneration

• Pterygium

• Contact lens corneal warpage

• Corneal manipulation during examination such as tonometry and gonioscopy

• Prior laser vision correction (LASIK, PRK, RK)

• Keratoconus