Cynthia A Toth, MD
Vitrectomy surgery is performed on anesthetized patients through 2 punctate plugs through the sclera on either side of the iris. Slender instruments are inserted through these ports into the vitreous. The instruments are used to cut, peel, or move retinal and epiretinal membranes and submacular fluids, either mechanically, hydraulically, or pneumatically. The surgeon performing the procedure views the operating field through the pupil of the patient's eye using a binocular operating microscope. New surgical techniques designed to improve outcomes, reduce operative trauma, reduce incidence of complications, and reduce postoperative pain associated with vitrectomy and other retinal procedures have recently been developed. These advances include miniature surgical instruments--such as forceps, scalpels, and scissors--that fit within the lumen of 23 gauge and 25 gauge vitrectomy instruments to mechanically cut, peel, and move retinal and epiretinal membranes. Powerful but slender intraoperative illumination sources designed to fit through the same punctuate plugs as the surgical instruments are now available. These devices simply provide better illumination of the surgical field, and should not be confused with endolaser probes which are used for treating retinal lesions in the same way as other laser photocoagulation procedures. Endolaser has the advantage of sparing the cornea, lens, and zonules from possible laser damage. Miniature fluid infusion and suction devices permiting hydraulic and pneumatic clearance of hemorrhage are also in current use. Pharmacological adjuvants are a recent development in vitreoretinal surgery, although neither of the adjuvants mentioned in this presentation are FDA-approved for the stated indications. Indocyanine green or trypan blue may be used to stain membranes or the vitreous to improve visualization. Potential toxicity has been reported with the use of indocyanine green if macular holes are present. Triamcinolone acetonide may be injected into the vitreous to reduce hemorrhage, improving visualization of the vitreous gel, membranes, or inner limiting membrane. Triamcinolone may also be used after vitrectomy surgery to treat macular edema or neovascularization, although it carries a risk of increasing intraocular pressure and cataract formation. |
