Fluorescein angiography versus optical coherence tomography-guided planning for macular laser photocoagulation in diabetic macular edema

Abstract

Purpose: To compare laser photocoagulation plans for diabetic macular edema (DME) using fluorescein angiography (FA) versus optical coherence tomography (OCT) thickness map superimposed on the retina.

Methods: Fourteen eyes with DME undergoing navigated laser photocoagulation with navigated photocoagulator had FA taken using the same instrument. Optical coherence tomography central retinal thickness map was imported to the photocoagulator and with same magnification aligned onto the retina. Three retina specialists placed laser spot marks separately on FA and OCT image in a masked fashion. The spots placed by each physician were compared between FA and OCT and among physicians. The area of dye leakage on FA and increased central retinal thickness on OCT of the same eye were also compared.

Results: The average number of spots using FA and OCT template was 36.64 and 40.61, respectively (P = 0.0201). The average area of dye leakage was 7.45 mm, whereas the average area of increased central retinal thickness on OCT of the same eye was 10.92 mm (P = 0.013).

Conclusion: There is variability in the treatment planning for macular photocoagulation with a tendency to place more spots when guided by OCT than by FA. Integration of OCT map aligned to the retina may have an impact on treatment plan once such information is available.

Fig. 1

Fluorescein angiography versus OCT-guided treatment plan for macular laser photocoagulation. A. Fluorescein angiogram overlayed on fundus photograph of an eye with diabetic retinopathy and mild macular edema (black arrow points to proper alignment of blood vessels and correct image overlay). Green circles represent laser spots to be applied during macular photocoagulation as outlined by Physician 1 (n = 17); yellow circles represent extrafoveal spots. B. Optical coherence tomography overlayed on fundus photograph of the same eye. Green circles represent laser spots to be applied during macular photocoagulation as outlined by Physician 1 (n = 32). C. Fluorescein angiogram overlayed on fundus photograph of the same eye. Green circles represent laser spots to be applied during macular photocoagulation as outlined by Physician 2 (n = 21); yellow circles represent extrafoveal spots. D. Optical coherence tomography overlayed on fundus photograph of the same eye. Green circles represent laser spots to be applied during macular photocoagulation as outlined by Physician 2 (n = 28).

Fig. 2

Fluorescein angiography versus OCT-guided treatment plan for macular laser photocoagulation. A. Fluorescein angiogram of an eye with diabetic retinopathy and macular edema used as a template for laser treatment planning. Yellow circles represent laser spots to be applied during photocoagulation as outlined by Physician 3 (n = 44). B. Optical coherence tomography overlayed on the same eye and used as a template for laser treatment planning. Yellow circles (white arrowhead) represent laser spots to be applied during photocoagulation as outlined by Physician 3 (n = 41).

Fig. 3

Comparison of OCT-guided treatment plans for macular laser photocoagulation. A. Optical coherence tomography retinal thickness map overlayed on fundus photograph with marked yellow spots (white arrowhead) for photocoagulation by Physician 1 (n = 61). B. The same template with marking by Physician 2 (n = 34).

Fig. 4

Comparison of FA-guided treatment plans for macular laser photocoagulation. A. Fluorescein angiogram of an eye with diabetic retinopathy and edema photograph with marked green spots (white arrowhead) for photocoagulation by Physician 1 (n = 25). B. The same template with marking by Physician 2 (n = 18).