Pseudoexfoliation And Cataract Surgery: Are There Biometric Characteristics That Can Be Linked To Intraoperative Complications?

Pseudoexfoliation syndrome (PEX) is characterized by the accumulation of abnormal fibrillar material, which is more commonly seen in the iris, the anterior capsule of the lens and the iridocorneal angle. Although PEX-associated zonular instability and iridopathy are commonly linked to the higher rate of intraoperative complications, there is little evidence regarding biometric characteristics in these patients and how they may affect the final surgical outcome. In this report we aim to analyse the biometric differences between PEX and normal controls and its relationship with intraoperative surgical complications.

Department of Ophthalmology, Centro Hospitalar de Vila Nova de Gaia/Espinho.

Observational cohort of 79 eyes of 79 PEX patients subjected to cataract surgery at our care centre. Patients underwent a complete ophthalmological evaluation prior to surgery, and the presence of exfoliative material, as well as other ocular comorbidities (such as glaucoma), were recorded. All underwent biometric evaluation (IOL Master 700, Zeiss) and data regarding anterior chamber depth (ACD), axial length (AL), lens thickness (LT), central corneal thickness (CCT), white-to-white (WTW), as well as keratometric values, were recorded. Intraoperative evaluation comprised the measurement of dilated pupil size and the description of observed complications. Collected data was compared with a 1:2 age and gender matched control group.

Mean age of PEX patients was 76 years; 58% were female. Mean AL (23 mm), keratometry (45 D), CCT (541 µm) and WTW (12 mm) were similar between the 2 groups; LT was higher in PEX (4,76 vs 4,64, p=0,04). Mean ACD (3,03) and percentage of patients with shallow (<2,5mm) chambers were comparable among the PEX/control groups (11,4 vs 8,2%, p=0,63). PEX had a higher proportion of patients with abnormal pupillary dilation (28 vs 2%, p<0,001). There was a significantly higher (22 vs 4%) proportion of PEX patients with intraoperative complications (p<0,001, odds ratio 5,9 [2,3-15,6]). Logistic regression analysis showed that pupil size and biometric parameters were not associated with an increased risk of complications, after controlling for PEX.  

Our report shows that there is not a relevant change in biometric features associated with PEX, and that neither the parameters' variability nor dilated pupil size seem to significantly impact the surgical outcome. A much higher rate of complications occurred in PEX patients when comparing with controls. In line with current evidence, we postulate that other surgical aspects, such as zonular instability, may be of significant higher value to the assistant surgeon in predicting intraoperative complications, rather than pure biometric readings.