Cataract surgery in cases with previous corneal surgery

Abstract

Cataract surgery in cases with previous corneal surgery can be a major challenge for the ophthalmologist as the visual and refractive outcome can be seriously affected. The surgeon has to preoperatively evaluate whether it is the cataract or the previous corneal surgery that most affects the visual acuity. The surgical procedure should be then carefully planned, to evaluate if a corneal graft surgery should be performed coincidentally to the cataract procedure or whether cataract surgery alone may sufficiently restore the best corrected vision of the patient. If phacoemulsification is possible, it is better to perform cataract surgery first to avoid risks which may occur with simultaneous surgery. Keratoplasty should be postponed to a later date. The refractive outcome of the case deserves special attention in the preoperative planning process and the reduction or elimination of the already existing astigmatism will be a desirable result. The authors will try to provide the practical cataract surgeon a review on this topic aiming to give guidelines for good clinical practice in the decision making process of these challenging and difficult cases.

Keywords::

• cataract
• corneal graft
• intraocular lens calculation
• keratoconus
• keratoplasty
• microincision cataract surgery
• refractive corneal surgery

Financial & competing interests disclosure

This study has been supported in part by a grant from the Spanish Ministry of Health, Instituto Carlos III, Red Temática de Investigación Cooperativa en Salud ‘Patología ocular del envejecimiento, calidad visual y calidad de vida’, Subproyecto de Calidad Visual (RD07/0062) and a grant from the Spanish Ministry of Economy and Competitiviness, Instituto Carlos III, Red Temática de Investigación Cooperativa en Salud (RETICS) ‘Prevención, detección precoz y tratamiento de la patología ocular prevalente, degenerativa y crónica’. Subprograma ‘dioptrio ocular y patologías frecuentes’ (RD12/0034/0007). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Cataract surgery in eyes after corneal surgery presents a unique challenge for refractive surgeons mainly due to difficulty in intraocular lens (IOL) power calculation and existing astigmatism.

• Patients should be informed about possible complications, especially postoperative refractive surprise.

• The most important issue is good planning of cataract surgery to achieve the most beneficial refractive and astigmatic outcome, which includes appropriate selection of the incision site with respect to a previous corneal procedure in most cases.

• Some transitory postoperative refractive shifts are common in cataract surgery following some previous corneal refractive procedures, such as radial keratotomy, and these should not lead to erroneous hasty decisions to perform additional procedures, such as IOL exchange.

• Accurate IOL power calculation is more difficult and requires unique measurements of corneal power and a customized approach to IOL calculation for each case.

• Modern microsurgical techniques, new IOL technologies, sophisticated biometry methods and advanced methods in IOL power calculation allow most cataract patients to regain an adequate refractive outcome and high quality of vision.

• Microincision cataract surgery with toric IOL may be the ideal surgery for most cases, in which previous corneal surgery has been performed. An adequate study of the regular and irregular patterns of the astigmatism in the corneal topography and aberrometry is mandatory for the decision-making process and for toric IOL calculation.