A Resident's Guide to Diabetic Retinopathy Surgical Treatment Options | Eyes On Eyecare

A Resident's Guide to Diabetic Retinopathy Surgical Treatment Options

by Eric K Chin, MD, Robin K. Kuriakose, MD, and David RP Almeida, MD, MBA, PhD

In this short course, we highlight the important variables to consider before, during, and after surgery for diabetic retinopathy.

5.0 (4 ratings)
Updated Mar 17, 2022
1 quiz
Course Contents
What You'll Learn
  • Review the comorbidities of diabetic retinopathy
  • Optimize imaging prior to vitreoretinal surgery
  • Identify the four steps of vitrectomy
  • Understand best practices for post-operative care

Introduction and Quiz

Diabetic retinopathy is the leading cause of vision impairment in the middle-aged population in the United States. The treatment options range from medical management in the clinic (e.g. intravitreal injections and laser for diabetic macular edema and proliferative diabetic retinopathy), to surgical management in the operating room for vitreous hemorrhage, retinal detachment, and membranectomy. In this review, we highlight the important variables to consider before, during, and after surgery.

diabetic vitreal hemmorhage

Figure 1: Diabetic vitreous hemorrhage.

Diabetic Retinopathy Surgery: Quiz

5 Questions

Take the quiz to test your knowledge of surgery for diabetic retinopathy!

Unlock this quiz now

Pre-operative checklist

Before Surgery

The ophthalmology resident should take into consideration the patient's general systemic medical health to first better determine the patient’s risk for ocular disease, and the risks that may be encountered during surgery. Generally speaking, a patient’s diabetic control (e.g., hemoglobin A1C) and the duration of diabetes may factor in their risk stratification for ocular disease and the potential complexities encountered during surgery.

The patient’s comorbidities such as heart disease, stroke, hypertension should also be taken into consideration, as these may make a patient’s surgery more complex or complicated. As an illustrative example, a patient recently encountered had elevated troponins and an acute exacerbation of congestive heart failure. The cardiologist requested the need for vascular catheterization and workup; however, the cardiologist had no objection to proceeding with monitored anesthesia care (MAC) surgery because the patient would likely need to be on anticoagulation after their cardiac procedure.

Sometimes holding anticoagulation medicines (e.g. aspirin, plavix, warfarin, etc) prior to eye surgery can be difficult, depending on comorbidity or past cardiovascular events (e.g., myocardial infarction or stroke). Similarly, a patient with uncontrolled blood pressure may have more difficult hemostasis during surgery, especially as it relates to retinal neovascularization. A patient’s body habitus and ability to lay supine for prolonged time periods may also make surgery more difficult depending on the level of sedation they are given by the anesthesia team.

Moreover, a patient’s history of vision changes and their past treatment is an important consideration. For example, a patient who had good vision, with new onset vitreous hemorrhage one week prior, may behave very differently from a patient who has chronic light perception vision for several months or years prior. Similarly, a patient who has had several intravitreal injections or panretinal photocoagulation laser (see Figure 5), may be at lower risk for intraoperative bleeding or tractional detachment, than a patient who has never had any prior treatment to their eyes.

When honing into the eye exam, it is important to consider the clarity of the view posteriorly. Is the cornea clear? How clear or opaque is the cataract? If the patient is young, be sure to counsel the patient of cataract progression after retina surgery so that it is considered as an expectation, rather than a complication. In fact, cataract formation occurs in up to 80% of eyes after pars plana vitrectomy within two years. Sometimes, a clear lens with dense vitreous hemorrhage, is difficult to manage because blood will accumulate posterior to a clear lens making the view more challenging.

In cases where there is dense vitreous hemorrhage, especially just posterior to the native lens, it may be advantageous for the patient to undergo cataract surgery prior to retina surgery. If an intraocular lens was recently placed, is the centration and intraocular lens stable? Were there any complications during recent cataract surgery, such as a ruptured posterior capsule? Is the posterior capsule intact or hazy? Does the iris dilate well or is there neovascularization of the iris that may put the patient at risk for anterior segment bleeding intra- or post-operatively?

Imaging prior to vitreoretinal surgery should be optimized. If the vitreous hemorrhage, for example, is mild, fluorescein angiography and optical coherence tomography (OCT) imaging can often give a better idea of the macula status. The extent of the neovascularization and the health of the macula (e.g., macular edema, ischemia, epiretinal membrane) should be considered to give better counseling to the patient. Residents will do well to have a low threshold for ultrasound evaluation of diabetics in cases of difficult visualization to better determine hyaloid and vitreous separation status. This will also better determine if the periphery or posterior pole has any significant traction from neovascular membranes. Knowing this prior to surgery can empower the surgeon to better counsel the patient as to whether or not a patient may need intraocular gas or silicone oil tamponade.

diabetic membrane removal.jpg

Figure 2: Removal of diabetic neovascular membranes.


During Surgery

A majority of vitreoretinal surgical procedures for diabetic patients are done in the operating room, often in an ambulatory surgery center, as an outpatient. A straightforward retinal surgery can range in time; however, complicated surgeries involving extensive peeling of membranes or detachment repair can last significantly longer. A patient should expect to have a driver for transportation. An overwhelming majority of surgeries are done while awake but comfortable under MAC by a skilled anesthesia provider. Often patients ask if they will be put to sleep, and my response to them is that they will be “awake but comfortable”, “twilight”, or “like having a colonoscopy” so that they can better understand the expectations during surgery. I discuss that we will “numb” the eye via a peri- or retrobulbar anesthetic block. The patient should expect to feel minimal pain or discomfort with this local anesthesia.

After the patient is positioned appropriately, and anesthesia is administered, the surgery begins. A brief summary of a standard vitreoretinal surgical approach is summarized below:

A point is marked 4 mm posterior the inferotemporal limbus and a 25-gauge (sometimes 23-or 27-gauge) valved trocar/cannula is inserted using a beveled approach to obtain a three-plane insertion. The position and function of the infusion cannula are always confirmed prior to use to ensure that the cannula is not in the suprachoroidal or subretinal space. Similar cannulas are then placed in the superotemporal and superonasal quadrants.

The vitreous needs trimmed closely near the optic nerve and a vitreous detachment either induced or verified. A core posterior vitrectomy can then be performed with removal of all unopacified vitreous and any vitreous membranes or vitreous hemorrhage present. Sometimes a dilute 50% mixture of triamcinolone is injected into the vitreous cavity to better visualize the remaining vitreous as a chromovitrectomy technique. Any remaining vitreous is then removed with the vitreous cutter and scleral indentation.

pars plana vitrectomy

Figure 3: Step 1 of a vitrectomy for a diabetic patient: Core vitrectomy

Critically, areas of neovascularization are segmented, dissected, peeled and removed with the vitreous cutter, and sometimes instruments like retinal forceps or a Tano membrane scraper can be used in addition. Panretinal photocoagulation is performed with an endolaser probe for 360 degrees to ensure complete treatment of the peripheral ischemic retina. Inspection is done with scleral indentation for 360 degrees to ensure there is no evidence of peripheral retinal breaks.

2peripheral blood.jpg

Figure 4: Step 2 of a vitrectomy for a diabetic patient: Peripheral vitrectomy