News in ophthalmology : Role of Anterior Segment OCT for Safer Management of Mature White Cataracts
Written by Abhinav Dhami MD
Optical coherence tomography (OCT) is a non-contact technique for high-resolution imaging of tissue. The majority of the available literature, however, focuses on its use in clear corneal incisions in phacoemulsification. The major challenge with white cataracts is in performing a complete circular curvilinear capsulorrhexis and minimizing the risk of the Argentinian flag sign. The incidence of incomplete capsulorrhexis associated with white cataract surgery is 28.3%, as reported in one study by Chakrabarti et al. Overall background retinal pathology, such as the presence of retinal detachment (rhegmatogenous/tractional) or presence of retinal/choroidal tumors, needs to be ruled-out with B-scan ultrasonography. The presence of fluid-filled and fluid-free cortex with white cataracts has been previously described, but there had been no clinical way of determining that presence. Surgical methods for managing white cataracts to date include the use of trypan blue dye, puncturing the anterior capsule with positive pressure in the anterior chamber, performing a two-stage capsulorrhexis, and using an insulin needle for capsular perforation and fluid removal. Recently, femto-laser–assisted capsulorrhexis has been added and allows for safer capsulorrhexis.
The use of anterior segment OCT (ASOCT) enables surgeons to localize this fluid-filled space and then perform needle-assisted fluid removal. When we used this approach, we preferred the 30-gauge versus the 26/27-gauge needle as it minimized the bevel-induced radial tear extensions. Thus, knowing which cases might require needle-assisted fluid removal is an advantage when using ASOCT