His practice specializes in medical, laser, and surgical treatment of glaucoma with a focus on minimally invasive glaucoma surgery (MIGS) and new glaucoma surgical devices. He also performs both routine and complex cataract surgery. Dr. Yohannan also specializes in the surgical management of complex problems of the anterior segment (front of the eye). These problems include issues that arise after trauma or prior surgery gone wrong such as dislocated intraocular lenses (IOL) or iris and pupil defects.