Vitreoretinal surgeons perform a multitude of surgical procedures. Some, including intraocular injections, pneumatic retinopexy, and laser photocoagulation, can be implemented in an office setting, while others, such as pars plana vitrectomy and scleral buckling, are restricted to surgical centers or hospital-based operating rooms.

For these common surgical procedures, allied health care staff excel at assisting the surgeon when they are familiar with the process — knowing which gauge needles, size syringes, or method of numbing, for example. The surgeon and clinical scenario dictate the appropriate surgical approach for each procedure, but the goal is always the same: for the patient to gain (or retain) as much vision as possible, with the greatest anatomical success.

Staff have a key role before the treatment as well. Generally, the ophthalmologist discusses the upcoming procedure with the patient prior to surgery, providing the risks, benefits, and alternatives. However, when the physician leaves the room, it is time for the allied health care staff to take over. Staff are responsible for answering questions, expanding on the pathophysiology of the disease process, explaining the upcoming treatment protocol, and, of course, reassurance and hand holding.

Here, surgeons describe some of the most common retina procedures and how allied health professionals can best assist with them.

Laser photocoagulation

Laser photocoagulation is a highly versatile therapy in ophthalmology. It involves the heating of tissues in the eye, which leads to many clinical benefits such as the formation of chorioretinal scarring, coagulating blood vessels, and reducing the production of growth factors, most importantly VEGF (vascular endothelial growth factor). Panretinal photocoagulation (PRP) is used to treat proliferative diabetic retinopathy by administering multiple laser applications to the peripheral retina. “Although anti-VEGF injections are used more frequently for diabetic macular edema (DME), focal, or grid laser is still effective, with long-lasting and randomized controlled study tested results,” says Michael Ober, MD, FACS, of Retinal Consultants of Michigan, chief of staff at Straith Hospital for Special Surgery, and associate professor of ophthalmology at Oakland University William Beaumont School of Medicine.

Laser sources have evolved from room-sized, water-cooled diode lasers, ruby lasers, and argon sources towards today’s compact multiwavelength continuous wave and/or micropulse devices designed to minimize collateral retinal damage.^1,2 Subthreshold micropulse laser therapy delivers less energy and allows dissipation of heat between pulses. When compared with conventional laser, subthreshold micropulse laser therapy causes less discernible permanent structural or functional effect on the retina.³

Pneumatic retinopexy

Pneumatic retinopexy is a multi-step outpatient surgery to repair a retinal detachment without the need for a conjunctival incision. It comprises the application of either transconjunctival cryopexy or laser photocoagulation to seal the retinal breaks before or after the injection of expansile gas to re-attach the retina and temporarily hold it in place.⁴ There are two common gases that can be injected for this purpose: sulfur hexafluoride (SF₆) or perfluoropropane (C₃F₈).⁵ Once inside an eye, pure SF₆ expands to twice its volume and lasts approximately 2 weeks, while C₃F₈ expands to four times its volume and lasts 6 to 8 weeks.⁶ To make room for the gas bubble in the eye, an anterior chamber paracentesis is required. It involves removing a small amount of aqueous from the anterior chamber, most commonly with a small gauge needle, but some physicians prefer making a small incision. The setup for these procedures is individual to the situation and physician preference and can be intimidating. The required equipment may differ slightly in an eye that has had cataract surgery, prior vitrectomy, or previous retinal detachment repair. “Preparing the multiple syringes, needles, sterile caps, gloves, filters, and gas are all tasks allocated to the ophthalmic assistant in the office just as in the operating room and require immense trust,” says Dr. Ober.

Although the procedure itself is less invasive than some, the postoperative care can be intensive. The patient must maintain the correct posture, usually specific positioning with the head tilted in one direction or another, for a period of time ranging from 24 hours to 7 days, to force the gas bubble to push directly against the retinal tear. Accurate instructions and reassurance from the allied health care professional can go a long way to ensuring success.

Pars plana vitrectomy

Pars plana vitrectomy is a common portion of the surgery to address multiple retinal disorders, including epiretinal membranes, macular holes and vitreous hemorrhage, proliferative diabetic retinopathy, among many others. It is also a method used in the treatment of acute retinal detachments, which may immediately follow a posterior vitreous detachment with retinal tears. Small gauge vitrectomy instruments, such as endoilluminators, forceps, drainage needles, and endolasers, can be safely introduced into the eye via trocars placed through the pars plana.⁷ A vitrectomy probe is inserted into the eye to delicately cut and remove the vitreous, separating the hyaloid from the vitreous base, and shaving the base down as much as possible with the goal of releasing tension.⁸ Following the procedure, the eye is filled with sterile saline, a gas bubble, or silicone oil, which may need to be removed at a later date.⁷

According to Michael Colucciello, MD, a retinal specialist with Vantage Eye Care, South Jersey Eye Physicians division, and a clinical associate with the University of Pennsylvania School of Medicine in Philadelphia: “It is very helpful if support staff understand why various intraocular tamponade agents are used, including perfluorocarbon liquid, silicone oil, SF₆ or C₃F₈, and why they are chosen.”

Scleral buckling

Scleral buckling as surgical intervention for retinal detachments is used less frequently with the advent of pars plana vitrectomy. However, it is still a required skill for both the surgeon and their operating room staff to hone, Dr. Colucciello says. “The scleral buckling procedure includes localization of the retinal break, cryopexy or laser photocoagulation, scleral buckling with a silicone band or sponge, including belt loops and scleral sutures, and subretinal fluid drainage.”

A chandelier endoilluminator with a wide-angle viewing system can assist with localization of breaks and is particularly useful for allowing the team to observe and stay engaged, Dr. Colucciello adds. “Being able to visualize the surgical field in real-time with the operating physician allows the ophthalmic assistant to anticipate subsequent steps and be ready with the next instrument.”

Conclusion

For staff who are just starting to learn these procedures, “It isn’t the speed of knowledge acquisition that is important for the allied health care professional, but enthusiasm and engagement,” Dr. Colucciello says. “Vitreoretinal surgery is dynamic, and although there are set out protocols, the processes are not by rote. They require critical thinking and active participation.”

Dr. Ober suggests that new ophthalmic assists pay close attention to colleagues who are more experienced. “There are many variables and nuances to each surgical procedure. Ask questions and take notes.” OP

REFERENCES:

1. Yadav NK, Jayadev C, Rajendran A, Nagpal M. Recent developments in retinal lasers and delivery systems. Indian J Ophthalmol. 2014;62:50-54.
2. Evans JR, Lois N, Armstrong DJ, et al. Different lasers and techniques for proliferative diabetic retinopathy. Cochrane Database Syst Rev. 2018;3:DC012314.
3. Scholz P, Altay L, Fauser S. A review of subthreshold micropulse laser for treatment of macular disorders. Adv Ther. 2017;34:1528-1555.
4. Hillier RJ, Felfeli T, Berger AR, et al. The pneumatic retinopexy versus vitrectomy for the management of primary rhegmatogenous retinal detachment outcomes randomized trial (PIVOT). Ophthalmology. 2019;126:531-539.
5. Stewart S, Chan W. Pneumatic retinopexy: patient selection and specific factors. Clin Ophthalmol. 2018;12:493-502.
6. Williamson TH. (2007) Vitreoretinal Surgery. Available from: https://www.springer.com/gp/book/9783642318719 . Accessed August 11, 2019.
7. de Oliveira PR, Berger AR, Chow DR. Vitreoretinal instruments: vitrectomy cutters, endoillumination and wide-angle viewing systems. Int J Retina Vitreous. 2016;2:28.
8. Vitrectomy. Available from: https://www.asrs.org/patients/retinal-diseases/25/vitrectomy . Accessed August 11, 2019.