WEST SIDE EYE SURGERY

Ocular Surgery & Potential Complications

Procedures

Cataract surgery and lens implant
Pneumatic retinopexy
Laser photocoagulation of retinal tears and vascular disease
Scleral buckle
Cryopexy
Vitrectomy
Vitrectomy for diabetes, macular hole and epiretinal membranes
Retinal detachment surgery

Complications

Dislocated intraocular lens cataract surgery
Bleeding (Intraocular hemorrhage) intraocular hemorrhage
Endophthalmitis (Infection) endophthalmitis
Extruding scleral buckle scleral buckle
Retinal incarceration scleral buckle

Cataract surgery

Disruption of the anterior vitreous face “vitreous loss” predisposes the eye to develop cystoid macular edema and retinal detachment, especially if vitreous strands adhere to the iris and wound. Insertion of the intraocular lens into the pre-existing lens capsular bag is preferred.

If the lens capsule fractures during surgery, the natural lens may drop into the vitreous cavity. A dropped or retained lens causes inflammation and glaucoma and may require a vitrectomy to restore ocular health.

The intraocular lens may become dislocated. The lens capsule of the eye is fixed to the wall of the eye with fine fibers called zonules. Age, manipulation at the time of surgery, and some conditions such as the pseudo-exfoliation syndrome, may weaken the zonules and so permit the lens capsule to stray from is appropriate location. The dislocated lens may fall into the vitreous, where vitrectomy techniques with intraocular forceps are used to retrieve and reposition the lens.

The overwhelming majority of procedures to remove a cataract and insert an intraocular lens go without complication. When a plastic or silicone lens comes in contact with the internal surface of the cornea, the corneal endothelial layer is injured. With excessive damage, at the time of surgery or post-implantation, the cornea may fail (corneal decompensation) to maintain sufficient transparency.

Pneumatic Retinopexy

An office-based treatment for a peripheral superior retinal tear and detachment, primarily used in patients who possess their natural lenses (phakic). After the tear is treated through external cryopexy, an expansile gas is injected through the pars plana. The gas expands and the patient and eye are positioned so the gas bubble presses against the tear, to seal the tear against the wall of the eye. The retinal pigment epithelium pumps out the residual sub-retinal fluid. A chorio-retinal bond becomes secure after several days. The failure rate for pneumatic retinopexy is about 1 in 7 – necessitating a second procedure such as a scleral buckle, a vitrectomy or both.

Retinal laser

Retinal laser is usually applied with a highly modified slit lamp with the patient and physician seated at a console. Occasionally the beam is delivered with an indirect ophthalmoscope. Focal and grid applications for diabetes are performed with low energy and are painless. Eye drops provide topical anesthesia. The eyelids are kept apart by a contact lens. Extensive treatment for proliferative diabetic retinopathy and lattice degeneration may be painful and necessitate injection of local anesthetic into the eyelids and orbit.

Retinal laser is applied in a focal or scatter array. It serves to seal leaking blood vessels, destroy ischemic retina or burn the RPE to create a scar. The greatest risk is a laser is a miss-hit to the center of the macula (fixation). Tolerances are close: many diabetic lesions are only 200 microns (1/5th of a millimeter) from fixation. If the burn is too intense, there may be lateral heat spread and collateral retinal damage and too much damage to the RPE setting the stage for choroidal neovascularization and scarring. Collateral retinal damage may become manifest months to years after the laser application. Heavy scatter peripheral laser may impair peripheral vision and visual field and lead to complaints of night blindness.

The most modern lasers (Pascal) can fire many spots simultaneously to speed therapy and lessen discomfort.

Scleral Buckle

Scleral buckling, an operative procedure, and the technique of choice for phakic retinal detachments, is about twice as effective and pneumatic retinopexy. A silicone element is sutured or secured to the external surface of the sclera and indents the wall of the eye to reduce traction at the site of a retinal tear. The tear is sealed with laser or cryopexy. Failure of primary repair for retinal detachment is expected in 10% of procedures. Retinal detachment repairs fail because the tear is not closed, there is an unrecognized tear or proliferative vitreoretinopathy.

In many cases, especially with excessive subretinal fluid, the sclera is punctured with a fine instrument or heated needle, to provide a pathway for the escape of the subretinal fluid. Attempts to drain subretinal fluid occasionally lead to subretinal bleeding, incarceration of retina into the drain site and choroidal hemorrhage. These are major complications and reduce the likelihood of a success in regard to both visual acuity and the overall rate of reattaching the retina to its original position.

Cryopexy

Cryopexy may have a greater potential than laser to induce macular pucker, and proliferative vitreoretinopathy.

In 5-10% of scleral buckle procedures, the synthetic elements sutured or otherwise attached to the wall of the eye will break through the conjunctival covering of the globe and become exposed. This produces discomfort, a “foreign body” sensation and a potential site for infection. The extruding elements are removed – and infrequently, the retina may re-detach.

Vitrectomy

In the standard (3-port) techniques, three incisions are made into the pars plana region to accommodate a light, a suction/cutter and a port for the infusion of a salt solution. Specialized light and cutter vitrectomy tools may have multifunction capability to scrape, cut, burn or grasp. Some surgeons use small gauge instrumentation and suture-less closure – but risk higher rates of infection and hypotony if the wounds fail to seal tightly.

When retinal tears or detachment is present, the fluid in the eye is replaced by a vitreous substitute, such as air, an expansile gas or silicone oil. The vitreous substitute as a temporary or long-lasting splint – to keep the retina in position while a local adhesion develops. Heavy liquid silicone may be used at the time of surgery or for short periods to press the posterior retina or inferior retina into place.

Cataract is frequent after vitrectomy, especially if the lens has been directly contused, and may happen in 50% of cases involving peels for macular pucker. Instrumentation through the pars plana is in close proximity to the peripheral retina and may occasionally cause a peripheral tear and detachment. Maneuvers close or on the retinal may produce tears or retinal contusions.

Possible risks of vitrectomy surgery include the development of new retinal tears or detachment, intraocular bleeding and rarely, infection (endophthalmitis).

Complications:

Endophthalmitis – intraocular infection occurs in 1/500 to 1/5000 procedures. Bacteria on the ocular surface (or more rarely in the bloodstream) enter the eye and proliferate to the detriment of the retina and other internal structures. Pain and loss of vision herald the infection, usually after two or more days after an invasive procedure. Prompt reecognition of the condition and the administration of intraocular antibiotics may salvage the eye and vision in some cases.

Intraocular hemorrhage – May develop in a variety of invasive procedures. When instruments are introduced into the eye, the intraocular pressure falls and vessels in the retina and uvea may bleed – spilling blood into the vitreous (vitreous hemorrhage) or choroid (choroidal hemorrhage). Neovascular complexes on the retina and iris are at high risk for bleeding, especially with ocular hypotension. Choroidal hemorrhage is notorious in high myopes undergoing scleral buckling. Excessive manipulation or surgical trauma to the retina and/or uvea may be responsible for vitreous hemorrhage in some cases. In a substantial number of vitrectomies for vitreous hemorrhage, peripheral vitreous hemorrhage cannot be completely evacuated, necessitating a second procedure or prolonged recovery as blood is slowly reabsorbed.