Innovation

Treatment of cataract disease

One of the most common misperceptions of cataract disease is that it is non-progressive, which unfortunately may create a bias toward conservative treatment options. If left untreated, patients with cataract disease will undergo a continuous degeneration of the lens, and in the latest stages, sequelae such as chronic uveitis, secondary glaucoma and retinal detachment may develop.  Complications from surgery are much less likely to develop if surgical treatment is performed early.

The Ophthalmology Service at the Cummings School of Veterinary Medicine at Tufts University leverages state-of-the-art surgical instrumentation and techniques to treat cataracts in dogs as well as many other species. Phacoemulsification to fragment and aspirate lens material is performed with minimally invasive access into the eye.  An artificial intraocular lens (IOL) is then introduced to reestablish Emmetropia (ideal state of the eye in which no refractive error is present).

Fig 3-A - 6 month post-op cataract surgery

Figure 3A – Right eye of a patient who has cataract surgery 6 months previously. The red arrows indicate a whitish halo representing fibrosis and lens fiber regrowth confined to the periphery of a square edged IOL.

The most advanced IOLs today are acrylic and foldable, and have square edges. The foldable lenses can be introduced through a thin cannula (Video 3A).  The “square edges” design creates physical contact with the posterior capsule, preventing migration of cells or newly formed lens fibers.  This migration occurs in 100 percent of patients, but has no or little clinical effect if confined to the periphery of the IOL (Fig 3A). Before the advent of this lens design, 35 percent of human patients undergoing cataract surgery eventually needed laser therapy for secondary cataract formation. With the change in lens design, that number has been dramatically reduced.

The Ophthalmology Service at Tufts has also introduced a technique for dividing the cataractous lens into four or more pieces using the Akahoshi lens splitter. This technique reduces surgical time and allows for easier aspiration of the lens material (Video 3B).

As important to our results as good surgical technique are appropriate patient selection and screening, and excellent perioperative care.