Table 3. Effects of laser photocoagulation on serum Ang-1, Ang-2, VEGF, Tie-2 and Ang-1/Ang-2 ratio levels in patients with PDR.

Items	Before laser photocoagulation	After laser photocoagulation	Z	P
Ang-1 (ng/mL)	9.57 (8.97-11.56)	9.93 (8.73-11.18)	-0.826	0.409
Ang-2 (ng/mL)	6.60 (3.13-7.34)	6.37 (2.55-7.37)a	-2.019	0.043
Ang-1/Ang-2	1.45 (1.25-2.33)	1.51 (1.27-2.78)	-1.740	0.082
VEGF (pg/mL)	487.8 (317.9-837.0)	451.4 (323.4-710.5)a	-2.095	0.036
Tie-2 (ng/mL)	3.05 (2.43-4.03)	3.04 (2.27-3.66)	-1.689	0.091

^aP<0.05 vs the pre-operative level.