Austin Fox, MD, discussed advancements in contact lens technology and use as part of a careful management strategy during Glaucoma Subspecialty Day at the American Society of Cataract and Refractive Surgery annual conference in San Diego.
The use of contact lenses after glaucoma surgeries has been controversial over the years, according to Austin Fox, MD, assistant professor of Ophthalmology at the Gavin Herbert Eye Institute at University of California, Irvine.
The bleb anatomy and contamination of contact lenses have been 2 of the major reasons for the disinclination to prescribe contact lenses for patients after glaucoma surgery.
With advancements in contact lens technology, contact lenses can be used successfully to achieve the best possible vision by adhering to a careful management strategy. He presented his pearls during Glaucoma Subspecialty Day at the American Society of Cataract and Refractive Surgery annual conference in San Diego.
Contacts are prescribed for numerous reasons included refractive error correction, irregular astigmatism, and ocular surface disease. An increase in the use of specialty contact lenses has expanded the options to serve patient needs, such as soft, corneal rigid gas-permeable (RGP), and scleral lenses.
After glaucoma surgery, the bleb or tube needs to be nearly flush with the ocular surface. Corneal RGPs or scleral lenses can be good contact lens options after glaucoma surgery, and soft lenses may be considered but should be of low modulus(highly flexible) if used.
]RGPs are smaller lenses that are rigid in contrast to the soft lenses. Fox noted that excessive movement of these lenses can cause mechanical trauma to the blebs, and maintaining centration can be difficult or impossible due to corneal pathology.
He advised that modifications can be made to minimize movement away from the bleb by decreasing the base curve, using reverse geometry RGPs, or using larger lens (intrapalpebral RGPs).
When considering scleral lenses, notches and vaults can be cut into the lenses to avoid problem corneal areas.
Fox offered a few recommendations for surgery. First,avoid over-hanging blebs by performing a fornix-based trabeculectomy and a modified Wise/Condon closure.
Second, preserve the limbus if possible with a sulcus tube shunt, pars plana tube shunt, or a scleral tunnel.
Finally, corneal patch grafts may allow for more consistent vault over a tube.
“Prevention is key,” Fox said. “Always lift or lower the lid during an examination, and watch for blanching/compression over the tube.”
Another consideration is monitoring the patient for thinning of tissue over tubes using optical coherence tomography.
“Glaucoma patients deserve the best vision possible, regardless of other corneal pathology, and this may require contact lenses,” he concluded. “We can accomplish this by working with our optometric colleagues for these select patients.”