Laser photocoagulation combined with intravitreal triamcinolone acetonide injection in proliferative diabetic retinopathy with macular edema

Abstract

Purpose: To evaluate therapeutic effects and usefulness of a combination treatment of intravitreal injection of triamcinolone acetonide (IVTA) and panretinal photocoagulation (PRP) in patients with clinically significant macular edema secondary to proliferative diabetic retinopathy (PDR).

Methods: Visual acuity test, fundoscopy, fluorescein angiography, and optical coherence tomography (OCT) were taken in 20 patients (20 eyes) of macular edema and PDR. A combination of intravitreal injection of triamcinolone acetonide and PRP was performed in 10 patients (10 eyes) and a combination of focal or grid laser photocoaqulation and PRP in the remaining 10 eyes. The postoperative outcomes were compared between the two combination treatments by best corrected visual acuity (BCVA), tonometry, fluorescein angiography, and OCT at 2 weeks, 1, 2, and 3 months.

Results: Average BCVA (log MAR) significantly improved from preoperative 0.56-/+0.20 to 0.43-/+0.08 at 1 month (P=0.042) and it was maintained until 3 months after a combination of IVTA and PRP in 10 eyes (P=0.007). The thickness of fovea decreased from average 433.3-/+114.9 micrometer to average 279.5-/+34.1 micrometer at 2 weeks after combined treatment of IVTA and PRP (P=0.005), which was significantly maintained until 3 months, but there was a transient visual disturbance and no significant difference in thickness of the fovea before and after treatment in the groups with PRP and focal or grid laser photocoagulation.

Conclusions: A combination of IVTA and PRP might be an effective treatment modality in the treatment of macular edema and PDR and prevent the subsequent PRP-induced macular edema result in visual dysfunction. In combination with PRP, IVTA might be more effective than focal or grid laser photocoagulation and PRP for reducing diabetic macular edema and preventing aggravation of macular edema without transient visual disturbance in patients requiring immediate PRP.

Fig. 1

Evaluation of mean foveal thickness and best corrected visual acuity after combined intravitreal injection of triamcinolone acetonid and panretinal photocoagulation. ^⋆: statistically significant difference between initial foveal thickness and each value, ^*: statistically significant difference between best corrected visual acuity before and after combination treatment.

Fig. 2

Changes of foveal thickness and best corrected visual acuity in patients treated with focal or grid laser photocoagulation and panretinal photocoagulation. ^*: statistically significant difference between best corrected visual acuity before and after laser treatment. The values of foveal thicknessare not significantly different from baseline.

Fig. 3

Fundus photographs (top), fluorescein angiograms (middle), and optical coherence tomography (bottom) of case 7 in combination treatment group. (A) Findings of initial examination. (B) One month after combined intravitreal injection of triamcinolone acetonide and panretinal photocoagulation. Late-phase fluorescein angiogram showing the marked decreased amount of leaking on macula and perivascular area. Note the decreased foveal thickness as seen on the optical coherence tomography.

Fig. 4

Fundus photographs (top), fluorescein angiograms (middle), and optical coherence tomography (bottom) of case 1 in laser treatment group. (A) Findings of initial examination. (B) One month after grid laser photocoagulation and panretinal photocoagulation. Late-phase fluorescein angiogram showing increased amount of fluid collection on macula. Note the increased foveal thickness as seen on the optical coherence tomography in spite of laser treatment.