Abstract
Purpose::
To assess the outcome of laser photocoagulation in patients with diabetic macular edema.
Methods::
Forty-seven patients (51 eyes) with clinically significant macular edema (CSME) undergoing grid laser photocoagulation were included. Clinical examination and optical coherence tomography (OCT) were performed at baseline and 3-4 months post-laser. The central foveal thickness (CFT), mean inner macular thickness (average retinal thickness in fovea and inner macular circle, IMT) and mean macular thickness (MMT) were calculated. Based on the OCT thickness, patients were grouped into; Group 1: Mild macular edema (<300 µm), Group 2: Moderate macular edema (300-399 µm) and Group 3: Severe macular edema (≥400 µm). Changes in CFT, IMT and MMT following laser treatment were noted.
Results::
Group 2 showed significant reductions in CFT (23µm, P=0.04), IMT (18 µm, P=0.02) and MMT (9 µm, P=0.04) with slight improvement in visual acuity. Groups 1 and 3 did not show any significant change in macular thickness values and there was a statistically insignificant worsening of visual acuity in these groups.
Conclusions::
Patients with moderate macular thickening of 300-400 µm do benefit most from laser treatment. OCT may help in choosing the appropriate treatment for CSME based on the degree of macular thickening. Long-term studies are warranted to confirm these findings. We have also described a relatively simple method of analysing the change in OCT thickness.
Keywords: macula/fovea • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • diabetic retinopathy