Current concepts in the management of cataract with keratoconus

Abstract

This review analyzed all pertinent articles on keratoconus (KCN) and cataract surgery. It covers preoperative planning, intraoperative considerations, and postoperative management, with the aim of providing a simplified overview of treating such patients. Preoperatively, the use of corneal cross-linking, intrastromal corneal ring segments, and topo-guided corneal treatments can help stabilize the cornea and improve the accuracy of biometric measurements. It is important to consider the advantages and disadvantages of traditional techniques such as penetrating keratoplasty and deep anterior lamellar keratoplasty, as well as newer stromal augmentation techniques, to choose the most appropriate surgical approach. Obtaining reliable measurements can be difficult, especially in the advanced stages of the disease. The choice between toric and monofocal intraocular lenses (IOLs) should be carefully evaluated. Monofocal IOLs are a better choice in patients with advanced disease, and toric lenses can be used in mild and stable KCN. Intraoperatively, the use of a rigid gas permeable (RGP) lens can overcome the challenge of image distortion and loss of visual perspective. Postoperatively, patients may need updated RGP or scleral lenses to correct the corneal irregular astigmatism. A thorough preoperative planning is crucial for good surgical outcomes, and patients need to be informed regarding potential postoperative surprises. In conclusion, managing cataracts in KCN patients presents a range of challenges, and a comprehensive approach is essential to achieve favorable surgical outcomes.

Figure 1

Flowchart of the approach to a patient with KCN and cataract

Figure 2

(a) Printout photograph of the Pentacam of the left eye with cataract and high astigmatism due to pellucid marginal degeneration. (b) Corresponding printout photograph of IOLMaster showing a higher cylinder; however, the magnitude of astigmatism is slightly lesser than seen on the topography. (c) Postoperative slit-lamp photograph in retroillumination showing the in-the-bag implantation of a customized toric intraocular lens. (d) The iTrace aberrometer shows a slight misalignment that can happen in patients with an irregular cornea. Postoperatively, however, the patient improved significantly and could read 20/50 unaided improving to 20/25 with −1.50 Dcyl

Figure 3

(a) Preoperative Pentacam image of the right eye of a patient with severe keratoconus with the presence of a posterior subcapsular cataract, showing an astigmatism of approximately 8 D. The patient underwent cataract surgery with implantation of hydrophobic customized intraocular lens. (b and c) Comparative pre and postoperative iTrace images of the same patients showing a marked reduction in the cylinder from −10.0 Dcyl to −3.5 Dcyl, respectively, with a best corrected visual acuity improving to 20/25

Figure 4

(a) Slit-lamp photograph of the right eye with advanced central ectasia and a distorted view of the anterior segment and the underlying cataract. (b) Topography map of the same eye showing a steep localized central cone. (c) Intraoperative image of the capsulorrhexis being performed through an RGP CL. The stained capsule helps enhance the view of the capsulorrhexis margin. (d and e) Intraoperative image of phacoemulsification being performed through a rigid gas permeable contact lens with minimal distortion and significant improvement in the surgical view