Risk Management

Unnecessary Laser Surgery for Diabetic Macular Edema

By Randy Morris, JD, OMIC Claim/Risk Management Associate, Digest, Fall 1998

ALLEGATION: Unnecessary panretinal photocoagulation for proliferative diabetic retinopathy.

DISPOSITION: Case settled on behalf of insured ophthalmologist.

Case Summary

A 63-year-old diabetic woman presented to the insured with complaints of decreasing distance vision. Laser surgery previously had been performed on her left eye for diabetic macular edema but not on her right eye. The insured diagnosed neovascularization elsewhere superior to the macula of the right eye and instructed her to return in one month for a fluorescein angiogram and panretinal photocoagulation (PRP).

A month later when the insured performed the fluorescein angiogram, he found progressive neovascularization elsewhere as well as perimacular and neovascular changes, hard extradites, a vascular loop and edema. Based on his interpretation of the angiogram, the insured performed PRP on the right eye. When the fluorescein angiography report came back after the surgery was performed, there was no mention of either neovascularization of the disc (NVD) or neovascularization elsewhere (NVE).

Twelve days post-op, the patient complained of loss of peripheral vision and severe pain in the right eye. The cornea was clear with no neovascularization. Visual acuity was 20/30 in the right eye. The insured reassured the patient that postoperative pain was normal. Over the next two months, visual acuity improved to 20/20 although the patient continued to complain of visual field loss and hazy central vision in the right eye. At her last visit, the insured referred the patient to a retina specialist. Visual field testing a year later by another physician showed significant visual field loss and a decline in visual acuity to 20/100 in the right eye.

Analysis

Defense experts were split on the issue of whether the patient exhibited enough signs of proliferative diabetic retinopathy to warrant treatment with PRP. One opined that the patient was a candidate for focal treatment of macular edema, but not PRP because she did not meet the criteria established by a 1976 diabetic retinopathy study, i.e., NVD greater than a 1/4 or 1/3 disk diameter or NVE. The other defense expert found signs of progressive PDR warranting PRP and supported the insured’s choice of spot size, macros and number of applications.

One of the plaintiff’s experts opined that the retinal photos and angiography taken by the insured did not reveal signs of diabetic retinopathy requiring treatment; therefore, it was below the standard of care to perform PRP in the absence of these objective findings and before reviewing the fluorescein angiogram results. This expert did admit that a fluorescein angiography is not required prior to performing PRP if the indications for the treatment are visualized prior to surgery as the insured had testified. However, there was no documentation of the insured’s findings prior to the angiogram and no mention of the angiogram findings to support the need for surgery. The plaintiff’s expert went on to say that even if the procedure had been indicated, the visual field loss was more than one would expect from a properly performed PRP. The patient had retained only 10% of her visual field.

Risk Management Principles

The insured’s failure to document any of his findings from the fluorescein angiogram was a major factor in the decision to settle this case. Although the defense expert made an excellent witness, it became clear during his deposition that this would be an extremely difficult case to defend. He was forced to admit, first, that neither the insured’s chart nor the fluorescein angiogram showed any documentation of either NVD or NVE and, second, that based on the color photographs in the insured’s chart, it was below the standard to perform PRP. Consequently, the only justification and support for performing PRP lay in the insured’s deposition testimony given one year after the operation.

In a busy practice it is often difficult to document the clinical interpretations and impressions that motivate medical decisions. This case exemplifies how taking just a few moments to record findings and interpretations, even those that seem trite or obvious, can save hours of litigation time and considerably bolster the defense should the practitioner’s care be called into question.