Surgical complications by their very nature are sudden, unexpected, and unavoidable. While complications involving the retina rarely occur during cataract and glaucoma surgeries, when they do, knowing how to minimize their impact and when to call in a retina specialist are key to acceptable outcomes.

We asked retina specialists Nancy M. Holekamp, MD, St. Louis, MO, and Victor H. Gonzalez, MD, McAllen, TX, to discuss some of the risks that threaten the retina during cataract and glaucoma surgery.

Retained Lens Fragment

When the posterior capsule breaks unexpectedly during a cataract surgery, the risks of retinal tear and postoperative cystoid macular edema increase. The cataract surgeon’s immediate concern is to stabilize the eye. But what should be done about retained lens fragments?

“The number 1 rule is: Don’t go fishing for the pieces in the posterior pole,” warns Dr. Holekamp. “It’s reasonable to perform an anterior vitrectomy and clean all of the vitreous off of the anterior segment structures. Definitely place an intraocular lens in the eye as you normally would, whether it is a sulcus-fixated lens or an anterior chamber lens. Then, close the eye, consider placing a suture in the wound, and refer the patient to a retina specialist.”

Most surgery centers don’t have a retina surgeon on staff, and, even if one is available when this complication arises, it’s not necessary to call him or her to the OR immediately, says Dr. Holekamp.

“It may seem expeditious to bring in a retina surgeon while the patient’s right there on the table, but that’s not advisable,” Dr. Holekamp says. “Not only would this second surgery require a different informed consent, but it isn’t necessary to remove the retained lens fragments the same day. It’s actually better to wait. The standard of care for this situation is for the retina surgeon to perform a vitrectomy within 1 week.”

Iris Trauma

When performing cataract surgery on an eye with a small pupil, the surgeon must take care to avoid inadvertently traumatizing the iris.

“If you do traumatize the iris, you run the risk of causing an inflammatory response, which can later result in macular edema or a uveitis type of response,” Dr. Gonzalez says. “To avoid this complication, use iris hooks or an iris ring to dilate the pupil to gain access to the lens while moving the iris away from the plane where the phaco tip will be doing its work.”

Suprachoroidal Hemorrhage

A suprachoroidal hemorrhage is a sudden catastrophic event that occurs when the pressure in the eye becomes so low that the choroidal vessels break, causing instantaneous massive bleeding behind the retina. It can have devastating consequences for a patient’s vision.

Although extremely rare, suprachoroidal hemorrhages have been reported in a variety of anterior segment surgeries, most often glaucoma surgeries, particularly those involving tube shunts.¹

“Acutely, the glaucoma surgeon must quickly close the eye with sutures and apply pressure to tamponade the bleeding until the blood clots,” says Dr. Holekamp. “There is no need to call a retina specialist to the OR, as the clotted blood cannot be drained. Drainage of suprachoroidal hemorrhages is best done as a delayed second procedure. The patient should be taken out of the OR and told about the complication.”

Dr. Holekamp stresses the importance of fully informing the patient about this complication and the need to be seen by a retina specialist.

“A suprachoroidal hemorrhage can be a devastating complication, as the patient can lose all vision,” she says. “But it can go well. The retina specialist will intervene 10 to 14 days later when the blood has had a chance to lyse and become liquid again.”

To decrease the risk of a supra-choroidal hemorrhage, Dr. Gonzalez advises creating the smallest incisions possible and avoiding maneuvers that could trigger a sudden rapid drop in intraocular pressure.

“Try to limit sudden decompression of the eye, and try to avoid excessive drainage immediately post-op, although that can be difficult with some glaucoma surgeries,” he says. “If you perform a trabeculectomy, for example, try to control the drainage with sutures for both the trabeculectomy and the conjunctival wound while not compromising IOP control. If you place a tube, make sure there’s no excessive leakage around the tube.”

According to Dr. Holekamp, certain eyes are at higher risk for suprachoroidal hemorrhage. These include: glaucomatous eyes that are aphakic or pseudophakic, highly myopic eyes, and eyes that have had a prior vitrectomy surgery and are undergoing a glaucoma procedure, such as a filtering bleb or a tube shunt. “But a suprachoroidal hemorrhage can happen in any open eye,” she warns.

Diabetic Macular Edema

Another risk of cataract surgery is the worsening of preexisting diabetic macular edema.² Managing this risk requires coordination between the cataract surgeon and the retina specialist.

“Diabetic macular edema (DME) is quite common in people who have had diabetes for more than 10 years,” says Dr. Holekamp. “Because we’re in the midst of a diabetes epidemic, many people in their 60s and 70s who have had diabetes for more than 10 years have DME and find themselves at the age when they need cataract surgery.”

If a patient seeking cataract surgery has undiagnosed DME, the preoperative OCT will reveal it.

“A patient who has significant DME should be referred to a retina specialist before proceeding with cataract surgery,” Dr. Holekamp says. “However, sometimes DME is persistent despite aggressive treatment, and the cataract must be removed during treatment. In these cases, the cataract surgeon and the retina specialist coordinate care to ensure optimal outcomes.”

Typically, the retina specialist will treat the patient with an anti-VEGF agent or an intraocular corticosteroid. The cataract surgery is usually scheduled midway between monthly anti-VEGF injections or 2 to 6 weeks after an intravitreal corticosteroid injection.

“The timing matters,” Dr. Holekamp says. “If, for some reason, a patient was not under the care of a retina specialist or was advised to go ahead with the cataract surgery by the retina specialist, the cataract surgeon can administer one of these drugs at the end of the surgery, keeping in mind that they’re not reimbursed by the ASC.”

Endophthalmitis

The risk of endophthalmitis following glaucoma or cataract surgery is quite rare.³ Nevertheless, it can occur, and management depends on visual status.

“Rarely does acute endophthalmitis require first-line management in the ASC,” Dr. Holekamp says. “Typically, the retina specialist will perform a vitreous tap and inject intravitreal antibiotics in the office. If a patient’s vision is light perception or worse, however, the condition is emergent, and a vitrectomy surgery is indicated.”

According to Dr. Gonzalez, “An overlying theme for both cataract and glaucoma surgeons with regard to endophthalmitis is prevention. I believe the evidence is strongest for the use of topical povidone-iodine, 5%, to prepare the eye.⁴ On the other hand, there is no evidence that using preoperative antibiotics is of any benefit.⁵ Intraocular infusion of antibiotics is controversial, and in the two surgery centers where I operate, we discourage the surgeons from using preoperative and intraoperative antibiotics, because number 1) the evidence doesn’t support it, and number 2) we have concerns about possible retinal toxicity with antibiotics.”

Medication Toxicity

Dr. Gonzalez warns that certain medications used intraoperatively have been found to be toxic to the retina.

“Inadvertent administration of intraocular gentamicin has been associated with severe retinal necrosis,”⁶ he says. “Also, intracameral vancomycin during cataract surgery has been associated with hemorrhagic occlusive retinal vasculopathy, although there is some question whether this is a toxicity response or an autoimmune response.”⁷

Dr. Gonzalez also advises caution when using compounded drugs, particularly those formulated for so-called dropless cataract surgery.

“It’s important to investigate the source to ensure that the compounding pharmacy utilizes best manufacturing practices and is in compliance with FDA regulations,” says Dr. Gonzalez. “Recently, reports of toxicity caused by compounded drugs used for this purpose have started to surface.”

Conclusion

Drs. Holekamp and Gonzalez stress that cataract and glaucoma surgeries performed in ASCs are safe, and that the complications discussed here are rare in any setting.

“Even in the best of hands, complications can happen if you perform enough surgeries,” says Dr. Holekamp. “I think an important takeaway message is that none of these complications must be managed on the spot in the ASC. A phone call at the end of the case, at the end of the day, or even the next day is sufficient to alert the retina specialist that you’re sending a patient for evaluation of a surgical complication.” ■

REFERENCES

1. Vaziri K, Schwartz SG, Kishor KS, et al. Incidence of postoperative suprachoroidal hemorrhage after glaucoma filtration surgeries in the United States. Clin Ophthalmol. 2015;9:579-584.
2. Chen XY, Song WJ, Cai HY, Zhao L. Macular edema after cataract surgery in diabetic eyes evaluated by optical coherence tomography. Int J Ophthalmol. 2016;9:81-85.
3. Eifrig CW, Flynn HW Jr, Scott IU, Newton J. Acute-onset postoperative endophthalmitis: review of incidence and visual outcomes (1995-2001). Ophthalmic Surg Lasers. 2002;33:373-378.
4. Ferguson AW, Scott JA, McGavigan J, et al. Comparison of 5% povidone-iodine solution against 1% povidone-iodine solution in preoperative cataract surgery antisepsis: a prospective randomised double blind study. Br J Ophthalmol. 2003;87:163-167.
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6. Brown GC, Eagle RC, Shakin EP, Gruber M. Arbizion VV. Retinal toxicity of intravitreal gentamicin. Arch Ophthalmol. 1990;108:1740-1744.
7. Witkin AJ, Shah AR, Engstrom RE, et al. Postoperative hemorrhagic occlusive retinal vasculitis: expanding the clinical spectrum and possible association with vancomycin. Ophthalmology. 2015;122:1438-1451.