The central lens thickness (CLT)
No statistical difference was noted between SVS and Orth-K groups for CLT before wearing glasses (p > 0.05). After wearing glasses for 6 and 12 months and after its withdrawal for 1 month, CLT from Orth-K group increased significantly when compared to the SVS group (all p < 0.01). In particular, after 12 months of wearing glasses, the difference between Orth-K and SVS groups (0.04 ± 0.02 mm and -0.01 ± 0.02 mm respectively) was statistically significant (p < 0.05). After withdrawal for 1 month, CLT from Orth-K group did not change significantly when compared to that before withdrawal (Table Summary, the results can be summarized as Figure 