develop disk hyperfluorescence after surgery and petalloid macular hyperfluorescence can be seen in diabetic eyes with macular edema that have never undergone surgery.43,44 Thus, the relative contributions of DME versus PCME in post-surgical macular

thickening can be difficult to assess in mixed clinical pictures.41,45 In the past, when it was thought that the

treatments differed for the two conditions, discriminating the components had greater importance. With the discovery that anti-inflammatory drugs can improve DME and that anti-VEGF drugs can

improve post-surgical macular edema, the importance of the distinction has diminished.46–53

With this background, there are two practical approaches that seem reasonable. If the patient is reasonably content and willing to proceed in a stepwise fashion, one could begin with the least invasive option and try topical prednisolone acetate and ketorolac for a month. If there is no improvement, then one could proceed to use periocular triamcinolone, and then if it resolves but recurs 3–4 months later, one could deduce by the process of elimination that the visible microaneurysms were of importance and selectively ablate them. If the patient is distressed and pushing the ophthalmologist for expedient relief, then a multi-pronged approach addressing all potential contributing sources at the same time would be rational – for example, simultaneous combined periocular triamcinolone plus focal photocoagulation.f

16.7Case 7: Proliferative Diabetic Retinopathy with Macular Traction and Ischemia

A 43-year-old female with diabetes and hypertension known for 5 years but present probably for many years longer has had blurred vision OS>OD for several months. The best corrected visual acuity is R – 20/25, L – 20/100. The intraocular pressure is 15 OU. Neither eye has iris neovascularization. Each eye has had one session of panretinal photocoagulation with 1,500 burns. Both fundi are shown as are the OCTs and sample frames from the fluorescein angiogram (Figs. 16.19, 16.20, 16.21, 16.22, 16.23, and 16.24). How would you manage these two eyes?

16.7.1 Discussion

The management of the right eye was controversial among the five reviewers of the case. Two reviewers thought that the neovascularization in the right eye was relatively inactive and that no further treatment

f Discussed by David G. Telander MD, PhD

Fig. 16.19 Red-free photograph of the right eye of case 7 showing retinal neovascularization, some preretinal hemorrhage, and a macular epiretinal membrane

Fig. 16.20 Red-free photograph of the left eye of case 7 showing retinal neovascularization, some preretinal hemorrhage, and a ring of preretinal membranes exerting traction on the macula

Fig. 16.21 Mid-phase frame of the fluorescein angiogram of the right eye of case 7 showing leakage from neovascularization, areas of capillary nonperfusion, and parafoveal intraretinal fluorescein leakage

Fig. 16.22 Mid-phase frame of the fluorescein angiogram of the left eye of case 7 showing extensive areas of capillary nonperfusion in the midperiphery and an enlarged and irregularly bordered foveal avascular zone

was indicated given the good level of vision. Three reviewers thought that the neovascularization showed continued activity and that further panretinal photocoagulation (PRP) was needed, but there was considerable disagreement about how to do this. One reviewer thought that focal/grid laser should be given first for a component of diabetic

macular edema, and then later that the PRP should be completed. Two reviewers thought that all of the macular thickening in the right eye was based on the epiretinal membrane (ERM). These reviewers did not think that the ERM was bad enough to recommend vitrectomy and membrane peeling. Two reviewers thought that PRP should be given alone,

but one favored use of pre-PRP intravitreal bevacizumab to reduce the neovascular activity rapidly. This level of disagreement in interpretation of clinical data and management is common in complicated cases of diabetic retinopathy. The point is

exemplified that cases in actual practice can be ambiguous in many respects. The discussant would argue that neovascular activity in the right eye seems evident, based on the fluorescein angiogram frame, and that the need for further PRP

therefore would seem to outweigh the risk that the ERM may contract and reduce vision when it is applied. Should the latter occur, prompt vitrectomy with membrane peeling should be able to remedy that eventuality. Although neovascular activity appears evident, it does not seem to be so severe as to threaten problems with hemorrhaging, thus there seems to be little reason to preface the supplemental PRP with an intravitreal bevacizumab injection, which carries a higher risk of ERM contracture than supplemental PRP alone.

For the left eye, two reviewers thought that vitrectomy was indicated to relieve the tractional component contributing to the visual loss. One of these two would preface the surgery with intravitreal bevacizumab and one would not. Neither of these two recommended further PRP before proceeding to surgery, but both would supplement the PRP at the time of surgery. Two reviewers thought that ischemia was the main cause for loss of vision in the left eye and that surgery should be deferred unless further progression to macula involving traction detachment occurred; neither of these reviewers thought that supplemental PRP to the left eye was needed. One reviewer thought that the left eye should have an intravitreal bevacizumab injection followed by completion of the PRP, but no surgery as long as the macula remained attached. Again, the diversity of opinions among experienced retina specialists is striking.

The fact that the patient presented with advanced disease suggests that follow-up is going to be a continuing concern, hence the discussant would favor completion of the PRP bilaterally to reduce the risk of subsequent vitreous hemorrhage, progressive fibrovascular proliferation with traction, and iris neovascularization. He favored no surgery of the right eye, but expected that it might be necessary if the ERM worsened later. He also favored vitrectomy surgery on the left despite the severe ischemia in hopes of removing the component of visual decline due to macular traction even though the center of the macula is not detached. Because this case was the discussant’s patient that is what was done. Six months later, the visual acuities of the right and left eyes were 20/70 and 20/40, respectively. Figures 16.25 and 16.26 show the appearance of the fundi at this point.

Because of the progressive decline in vision of the right eye, vitrectomy, membrane peeling was

Fig. 16.25 Progressive thickening of the macular epiretinal membrane of the right eye of case 7

Fig. 16.26 Post-vitrectomy fundus photograph of the left eye of case 7. Release of macular traction is apparent but residual vertical retinal striae are seen

recommended and performed. At follow-up 1 month later the visual acuity of the right eye had improved to 20/30 and the vision in the left eye had further improved to 20/30. Figure 16.27 shows the postoperative appearance of the right fundus.

Several points are illustrated. First, the assessment of visual potential based on capillary nonperfusion is fraught with error (see Chapter 8). No reviewer of this case considered that a 20/30 outcome for the left eye was possible at