Case report

A 65-year-old retired graphic designer who was non-insulin dependent diabetic was referred to the vitreoretinal team for consideration of surgical treatment for exudative diabetic maculopathy. He had previously had unsuccessful macular grid and focal Argon laser treatment at his referring unit. On presentation, his corrected visual acuities were right 3/60<N48 and left 6/36<N48. Anterior segments were normal. Fundoscopy revealed extensive intraretinal hard exudates at both posterior poles, more pronounced at the right macula as shown in Figure 1. Fluorescein angiogram revealed macular oedema in both the eyes.

Figure 1
figure 1

Fundal photographs: (a) left posterior pole preoperatively, (b) right posterior pole preoperatively with larger macular exudate, (c) right eye at 2 months postoperatively, and (d) right eye at 5 months.

Full size image

The possibility of surgical intervention was discussed with the patient. He was keen despite a guarded prognosis and potential complications of surgery. With his informed consent, he underwent a standard right three port pars plana vitrectomy followed by a small partial thickness retinotomy made with a sharp pick just temporal to the massive macular hard exudate. The hard exudate was debulked using saline irrigation with a narrow gauge cannula and sub-retinal forceps through the retinotomy. After fluid-air exchange, 4 mg of intravitreal triamcinolone and 15% C3F8 gas, were injected. A face down posture was recommended for 1 week to allow time for the retinotomy site to heal.

At 2 months follow-up with refraction, his visual acuity was 6/60 N24 right. He stated that he had better depth perception, his vision was brighter and he could now watch the television at 3 m whereas previously he had to be within 1 m of the screen. His near vision had improved (<N48–N24). Fundoscopy showed a significant reduction in the size of the macular exudates (Figure 1c).

Visual outcome for the right eye remains satisfactory after 20 months at 6/60 N24 with subjectively increased depth perception and contrast sensitivity.

Comment

Diabetic maculopathy is an important cause of visual impairment. The current treatment for clinically significant macular oedema is focal or grid Argon laser photocoagulation to stabilise vision.1 In advanced cases, laser treatment is ineffective. Massive deposition f macular hard exudates carries an increased risk of subretinal fibrosis.2 With this in mind, other treatment modalities have been attempted. Yang3 performed vitrectomy, focal endolaser, and panretinal photocoagulation, and showed regression of both macular oedema and hard exudates. Intravitreal triamcinolone alone has been reported to reduce macula oedema and the amount of hard exudates.4, 5 Takagi et al,6 Sakuraba et al,7 and Takaya et al8 have removed macular hard exudates surgically following vitrectomy. Despite good anatomical results, visual acuity improvement was not maintained long term with surgical removal alone because of atrophic or degenerative changes.8 A combined procedure of surgical debulking and intravitreal triamcinolone would theoretically simultaneously reduce both macular exudate and oedema in a shorter period of time thereby reducing the risk of subretinal fibrosis.

Our patient was very keen for any surgical intervention to improve his vision despite a guarded prognosis and the potential risks of surgery. To our knowledge, this is the first published report of surgical removal of macular hard exudate combined with intravitreal triamcinolone. More experience is currently required to observe the long-term benefit of such intervention as well as its appropriate timing with respect to the disease process.