Cataract Surgical Planning Using Ultrasound Biomicroscopy In Patients With Pseudoexfolation Syndrome

Our aim is to prove the utility of ultrasound biomicroscopy (UBM) in the assessment of zonular appearance of patients diagnosed with pseudoexfoliation syndrome before and at 1- and 6-months follow-up after cataract surgery. 

Clinical Emergency Eye Hospital, Department of Ophthalmology, Bucharest, Romania.

The study group was composed of 10 patients clinically diagnosed with pseudoexfoliation syndrome (PEX) and age-related cataract and the control group formed by 10 patients with age-related cataract and no PEX material. The clinical diagnosis of PEX was based on the presence of fibrillin deposits at the pupillary border and on the anterior lens capsule, pupillary ruff loss and poor pharmacological dilation. Patients with PEX are known to associate complications during cataract surgery and, later on, intraocular lens dislocation. UBM was performed before cataract surgery and at 1-month and 6-month follow-up to report pseudophakic dislocation. Cross-sectional UBM measurements were done using a 35MHz frequency transducer in supine position. 

Out of 10 patients, 1 had posterior lens dislocation and 3 were diagnosed with secondary open angle glaucoma. Healthy zonules appear on UBM as straight, medium reflective lines. Zonules of PEX patients can be divided into 3 categories: the granular type appeared in 2 patients, the sclerotic type appeared in 2 patients and the fan-shaped type appeared in 6 patients. During cataract surgery, 2 patients experienced floppy iris syndrome and needed iris hooks. Zonular instability in 3 other patients required the insertion of capsular tension rings. At 1 month follow-up, the implanted intraocular lenses were in optim position. At 6-month follow-up, 1 patient presented with spontaneous pseudophakic dislocation due to zonular dehiscence.

UBM proved to be a useful tool in planning of cataract extraction, as it can precisely localize zonular abnormalities and identify subjects at risk for complications. Thus, the surgeon can anticipate potential difficulties and take appropriate precautions. It is also used to analyze parameters hard to visualize on slit-lamp examination of the anterior and posterior chamber, as well as establish the type of glaucoma. UBM examination proved of greatest value in patients with synechiae or insufficient mydriasis, in which posterior structures could not be examined. Future widely-accepted criteria for zonular dysfunction regarding their aspect on UBM, especially for PEX patients, will be even more beneficial in preoperative assessment.