The use of contact lenses after glaucoma surgery has been controversial for years, according to Austin Fox, M.D., assistant professor of ophthalmology at the Gavin Herbert Eye Institute at the University of California, Irvine.
Two of the main reasons for reluctance to prescribe contact lenses to patients after glaucoma surgery are the anatomy of the bulla and contact lens contamination.
Advances in contact lens technology allow successful use of contact lenses to achieve the best possible vision by following careful management strategies. announced the pearls at the Glaucoma Subspecialty Day.
Contact lenses are prescribed for a variety of reasons, including refractive error correction, irregular astigmatism, and ocular surface disease. The increased use of specialty contact lenses has expanded options to meet patient needs, including soft, corneal hard gas permeable (RGP), and scleral lenses.
After glaucoma surgery, the bleb or tube should be approximately flush with the eyeball surface. Corneal RGPs or scleral lenses may be excellent contact lens options after glaucoma surgery.
]RGPs are lenses with less stiffness in contrast to soft lenses. Fox noted that excessive movement of these lenses can cause mechanical trauma to the bulla, and corneal pathology can make centering difficult or impossible.
He says modifications can be made to minimize movement away from the bleb by reducing the base curve, using a reverse geometry RGP, or using a larger lens (intrapalpebral RGP). advised.
When considering a scleral lens, notches and vaults can be cut into the lens to avoid problem corneal areas.
Fox provided several recommendations for surgery. First, perform a vault-based trabeculectomy and a modified Wise/Condon closure to avoid bleb overhang.
Second, use a grooved tube shunt, pars plana tube shunt, or scleral tunnel to preserve the limbus if possible.
Finally, corneal patch implantation may allow for more consistent vaulting over the tube.
Monitoring contact lens wear
“Prevention is key,” said Fox. “Always raise and lower the lid during inspection and watch out for whitening/compression of the tube.”
Another consideration is using optical coherence tomography to monitor the patient for tissue thinning over the tube.
“Glaucomatous patients deserve the best possible visual acuity, regardless of other corneal pathologies, and this may require contact lenses.” By collaborating with our colleagues, we can achieve this.”