Table 2.

Comparison of average retinal thickness and peripapillary retinal nerve fiber layer(ppRNFL) thickness before and after the CCL surgery in patients with keratoconus (n = 22)

Variable	Pre-operation	1 Month post-operation	3 Months Post-operation	P-value*
ART(µm)
total	78.63 ± 2.68	79.13 ± 2.69	80.13 ± 4.03	0.31
superior	79.18 ± 2.85	79.5 ± 2.87	80.9 ± 4.41	0.13
inferior	78 ± 2.76	78.68 ± 2.96	79.36 ± 3.84	0.25
Peripapillary RNFLT(µm)
global	105.95 ± 12.32	101.81 ± 23.98	107.22 ± 11.77	0.28
superior temporal	135.27 ± 20.22	136.09 ± 22.07	125.9 ± 14.13	0.42
temporal	74.36 ± 10.73	75.22 ± 12.09	75.68 ± 8.94	0.5
inferior temporal	156.9 ± 17.55	155.68 ± 17.23	157.4 ± 16.39	0.77
superior nasal	117.59 ± 31.61	120.54 ± 32.46	124.27 ± 28.43	0.3
nasal	90.77 ± 16.94	87.22 ± 23.59	94.68 ± 17.16	0.08
inferior nasal	126.4 ± 35.93	124.31 ± 40.39	124.54 ± 33.69	0.48

ART: average retinal thickness, RNFLT: retinal nerve fiber layer thickness, (µm): micrometer

*Friedman test

P-values < 0.05 were considered as statically significant, all data were presented as mean ± standard deviation