OCT Is Indispensable for Pre-op Cataract Evaluation
By Ashley Brissette, MD, MSc, FRCSC
As we refine the refractive outcomes of cataract surgery, patient expectations will also continue to rise. As such, I find that preoperative screening for any macular pathology is essential, and OCT is part of that process, along with clinical examination. Preoperative screening with OCT helps me not only identify subtle preexisting macular pathology, but also allows me to counsel patients on intraocular lens selection and set expectations for visual recovery.
Screening Helps Identify Pathology and Set Expectations
Many retinal pathologies can be detected by OCT. This is especially true in the context of an advanced cataract where the view to the fundus may be impeded. However, I have also been surprised by subtle pathologies, such as trace epiretinal membrane (ERM), vitreomacular traction, and even subclinical cystoid macular edema (CME) in more straightforward cases when imaging preoperative cataract surgery patients.
Even a mild ERM can lead to an increased risk of postoperative CME, and this would be important to discuss with patients prior to surgery, thereby setting appropriate expectations. In fact, any concurrent eye diseases must be discussed prior to surgery. Best-case scenario, there are no complications in the post-op period. However, if something does arise, you can feel confident knowing the patient was appropriately evaluated and informed before surgery. I make sure to compare the macular thickness and foveal contour of the two eyes.
In the preoperative patient, these findings may be hard to appreciate clinically, especially in the presence of a visually significant cataract, which is why OCT is helpful as a screening tool. In fact, studies have demonstrated that OCT can effectively diagnose macular changes preoperatively and postoperatively.1
Who Gets Preoperative OCT
In my practice, I obtain a preoperative OCT for any patient in whom the cataract is obscuring my view of the fundus or if there is clinically evident macular pathology. I also use OCT preoperatively for any patient who is receiving a premium lens, such as a toric or multifocal lens, because premium lenses come with premium expectations. The pre-op OCT is included in the premium lens package. In my experience, patients appreciate the thorough screening, especially if they understand its impact on the intraocular lens selection and their visual outcomes.
OCT helps ensure that expectations can be fulfilled by identifying any pathology in advance. I also obtain an OCT so I can be sure I’m making the best recommendation for my patient in terms of lens selection. With OCT screening, I’m confident patients will have optimal outcomes based on their individual visual requirements.
Obtaining an OCT should be quick, efficient, and easy to incorporate into the preoperative evaluation. Current OCT technology is capable of all of this; the retinal detail is superb, and obtaining the imaging is easy for our technicians because the software automatically centers the measurements after obtaining the image. Therefore, it does not add much time to the examination to obtain these images.
Education and Screening Go a Long Way
Lastly, preoperative screening with OCT helps me educate cataract patients about their eye health and what they may expect during their visual recovery. I show patients their images to illustrate how certain comorbid findings may affect their visual outcome. Anything discovered after the cataract is removed will be thought of as having been caused by the surgery. Preoperative OCT allows me to detect the problem, explain it to the patient, and set expectations accordingly. For me, this is an indispensable part of preoperative cataract screening.
Figure 1. OCT Epithelial Thickness Map of keratoconus highlights localized epithelial thinning.
Figure 2. OCT Epithelial Thickness Map of post-myopic LASIK shows epithelial remodeling resulting in central thickening at ablation zone.
Figure 3. OCT B-scan cross section reveals localized thinning inferiorly (left side of b-scan image) of keratoconus case.
Moreira Neto CA, Moreira Junior CA, Moreira AT. Optical coherence tomography in patients undergoing cataract surgery. Arq Bras Oftalmol. 2015;78(4):241-245.
Ashley Brissette, MD, MSc, FRCSC, is an assistant professor of ophthalmology at Weill Cornell Medicine, New York Presbyterian Hospital. She is a consultant for Carl Zeiss Meditec.