2.Use 20 gauge instrumentation and vertical automated scissors.

3.Use a lighted infusion cannula to allow bimanual technique with one hand grasping and the fellow hand operating the vitrector or the scissors.

4.Apply intraoperative panretinal laser photocoagulation only to the attached peripheral retina.

5.Make no intentional retinotomies, but if an iatrogenic break occurs, aggressively resect all fibrovascular membranes, apply panretinal laser photocoagulation after flattening the retina with an air–fluid exchange, and finish the case with a silicone oil–air exchange.

6.Aim to relieve all traction on the retina, create no iatrogenic breaks, and leave the eye with its subretinal fluid to be pumped out by the retinal pigment epithelium.

7.In the office postoperatively, apply panretinal photocoagulation posteriorly (where the subretinal fluid is) after the retina flattens, which might take several weeks to occur.

In considering these various opinions, it is not possible to say which technique would offer the patient the best chance of a good outcome, as they reflect the individual aspects of different surgeons’ training and experience. Furthermore, there are no randomized trials comparing specific techniques that are applicable to just such a case as this. It is worthwhile, however, to emphasize the differences of opinion and where consensus is present. The use of preoperative bevacizumab is contentious. Opinion 1 omits reference to it, opinion 2 explicitly argues against its use, and opinion 3 recommends using it. Case series have reported that use of preoperative bevacizumab reduces vascularity and intraoperative bleeding, but can cause

contraction of fibrovascular membranes in approximately 5% of cases.9,22,23 One case report

has been published of a patient losing vision from hand motions to no light perception shortly after an intravitreal bevacizumab injection, but the discussants of the case were doubtful that cause and effect could be established.24 If bevacizumab is used in such a case, the consensus of opinion seems to be that the surgery should follow within 4 days to reduce the chances of fibrovascular membrane contracture.9 We think it is valuable to

expose the reader to the spectrum of thinking about the problems raised by such a case.b

16.3Case 3: Sight Threatening Diabetic Retinopathy in a Patient with Concomitant Medical and Socioeconomic Problems

A 61-year-old male was referred by an emergency room doctor. The patient was on no diabetic therapy and complained of 6 months of painless, fluctuating, blurred vision OU. He stated, ‘‘I am a borderline diabetic.’’ He had no primary care doctor, no insurance, no Medicaid, no Medicare, no job, no money, and took no medication. The state blind commission had exceeded its yearly budget and was authorizing no more treatments until the next fiscal year.

The examination showed the following:

Blood pressure was 165/95

Fingerstick blood glucose in office was 283

Best corrected visual acuity was 20/63 OU

Phakic with early nuclear sclerosis OU

Fundus appearance OS as shown (Fig. 16.7)

OCT OS as shown (Fig. 16.8)

The situation OD was similar

How would you manage this case (tests, treatment, follow-up intervals, primary care arrangements)?

16.3.1 Discussion

The patient has untreated diabetes mellitus, hypertension, diabetic macular edema (DME), and proliferative diabetic retinopathy (PDR) based on the presence of a twig of neovascularization at the temporal disk margin. The medical issues in this case are straightforward. The patient needs medical care and education about diabetes and hypertension, needs appropriate treatment to tightly control his blood sugar and blood pressure, and once this systemic treatment plan has been put in place, needs

ophthalmic intervention to reduce the DME first and the PDR second (see Chapters 4, 7, and 9).25–27

b Discussed by David J. Browning MD, PhD