Peripapillary RNFL and Retinal Edema Change After Photocoagulation or Anti-VEGF Injection in Diabetic Retinopathy: Misinterpretation of Peripapillary RNFL Thickness and its Adjustment Using New RNFL Thickness / Retinal Thickness Index


SCIENTIFIC POSTER

Peripapillary RNFL and Retinal Edema Change After Photocoagulation or Anti-VEGF Injection in Diabetic Retinopathy by Hyun Seung Yang, South Korea


ABSTRACT

Objective:

To investigates the change for peripapillary retinal never fiber layer (RNFL) and retinal edema in diabetic retinopathy (DR) patients after panretinal photocoagulation (PRP) and intravitreal anti-VEGF injection and its correction using the relationship between the peripapillary RNFL and corresponding retinal edema after treatments.

Design & Methods:

Among 212 eyes of 212 consecutive treatment naïve patents with moderate to severe non-proliferative diabetic retinopathy, 122 eyes were treated PRP (group I; n=72) or anti-VEGF (group II; n=50), and 90 eyes (group III) were included as a control in this retrospective, observational, consecutive case series. A complete ophthalmic examination, including peripapillary RNFL, retina and choroidal thickness using spectral-domain optical coherence tomography was performed at baseline and at 6 and 12 months. For each scan, we determined peripapillary quadrant RNFL thickness and evaluated the relationship with peripapillary retinal and choroidal thickness. Using the relationship, RNFL thickness was corrected (A new RNFL index; peripapillary RNFL thickness divided by corresponding peripapillary retinal thickness).

Results:

Peripapillary temporal quadrant RNFL thickness after PRP showed increased RNFL thickness at 1 year (p=0.001) and corresponding peripapillary retinal thickness was also thickened (p=0.021). However, the RNFL thickness after intravitreal injection was decreased in the all quadrants (p<0.001) and corresponding peripapillary retinal thickness was also thinned (p<0.001). Peripapillary RNFL thickness is very closely correlated with the peripapillary retinal thickness (R=0.793) but not with corresponding peripapillary choroidal thickness (R=0.057). A new index analysis to adjust the effect of retinal edema showed no significant change of peripapillary temporal RNFL change in group I (p=0.752) and II (p=0.532) but RNFL index of group III decreased significantly (p=0.024).

Conclusion:

Peripapillary RNFL thickness is strongly affected by the peripapillary retina edema fluctuation after treatments so that the thickness itself does not mean the real RNFL gain or loss. Thus, correction of edema component using the index is necessary for better analysis of RNFL thickness in DR patients with peripapillary retinal edema before and after treatments.


CONTACT DETAILS

 

Hyun Seung Yang
Department of Ophthalmology, Seoul Shinsegae Eye center, Eui Jung Bu, Gyeonggi-do, South Korea
Email : yangg961@gmail.com

Young Hee Yoon
Department of Ophthalmology, University of Ulsan, College of Medicine, Asan Medical Center, Seoul, South Korea