The treatment for the DME should be focal/grid laser photocoagulation.28 The treatment for the PDR should be panretinal laser photocoagulation.29 It would be preferable to have resolution of the DME before addressing the PDR, thus focal/ grid laser should be applied and after 4 months, if DME persists, reapplied until either the DME has resolved or maximal treatment has been placed with refractory DME remaining.30 In the Early Treatment Diabetic Retinopathy Study, the average number of focal/grid laser treatments required for an eye with clinically significant macular edema was 3.8, so the ophthalmologist should expect to treat this eye multiple times. In many cases, one cannot wait until DME has resolved before addressing the PDR. One may proceed with PRP together with treatment of the DME in such cases. Based on clinical experience rather than evidence from randomized clinical trials, an adjunctive agent such as intravitreal triamcinolone or bevacizumab may be useful in such a situation.31

The difficult issues in this case are not the medical ones, but rather the social ones. It is challenging to arrange care by an internist in the United States for such a patient. If the ophthalmologist lives in an area with a medical school, there may be provision for care of the indigent there. Some communities have clinics for the indigent, but the care may be haphazard and they are frequently understaffed. Few ophthalmologists feel qualified to treat diabetes and hypertension themselves, or some feel that they would incur unacceptable follow-up obligations and legal liability were they to begin medical therapy themselves. Thus, the systemic foundation in such a case will frequently be lacking. In such cases, the ophthalmologist can verbally encourage the preferred care at each ophthalmic visit and facilitate obtaining it as far as possible. Often the ophthalmic aspects of treatment will need to be applied regardless of optimization of the systemic factors.

The issue arises – should ancillary studies be obtained in such a situation, and is standard care to be followed? One of the panel reading this case commented that he does not change his practice based on the patient’s economic circumstances (opinion#1). He would obtain a fluorescein angiogram (FA) and optical coherence tomogram (OCT), treat the patient in the preferred manner,

follow-up and monitor with OCT as for anyone else, and set up a payment plan ‘‘even for $5 per month.’’ Another reading the case would treat based on the clinical appearance only, omit both the FA and OCT, and would alter the treatment plan. This physician would begin with an intravitreal injection of triamcinolone and follow with a combined focal/grid and a full panretinal laser photocoagulation treatment 1 week later (opinion#2). Follow-up OCTs would be omitted, but visits would continue at 4-month intervals. In the discussant’s experience, the ophthalmologist’s approach to such cases depends on what proportion they represent of his practice. If such cases comprise <5% of the ophthalmologist’s cases, the approach is often that of opinion#1. If such cases comprise 10%, 20%, or more of the practice, the approach begins to approach that of opinion#2. Ophthalmologists who practice in countries with nationalized health care seem to face fewer issues of this nature.c

16.4Case 4: Asymptomatic Retinal Detachment Following Vitrectomy in a Patient Who Has Had Panretinal Laser Photocoagulation

A 62-year-old man with type 1 diabetes for 35 years and hypertension for 25 years had panretinal photocoagulation for proliferative diabetic retinopathy and focal/grid laser photocoagulation for diabetic macular edema of the right eye 3 years before. He subsequently developed a macular epiretinal membrane with persistent macular edema of this eye for which he underwent vitrectomy with membrane peeling. At routine follow-up 2 months after surgery, a peripheral rhegmatogenous retinal detachment was noted with a post-sclerotomy horseshoe tear in the superotemporal quadrant (Figs. 16.9 and 16.10). At this visit he was asymptomatic and his best corrected visual acuity was 20/40 right and 20/60 left. How would you manage this case?

c Discussed by David J. Browning MD, PhD