AIM: To evaluate the treatment selections and outcomes of keratoconus and discuss the grading treatment of keratoconus. METHODS: Medical records of 1162 patients (1863 eyes) with keratoconus treated with rigid gas permeable (RGP), corneal collagen crosslinking, and keratoplasty were reviewed. The patients were grouped according to the CLEK Study. The advanced group was further divided into a <60 D group and >60 D group. The best-corrected visual acuity (BCVA) and topographic data before and after treatment were recorded. RESULTS: In the 761 eyes with steep K<52 D, nonsurgical management accounted for 83.4%, while in the 735 eyes with steep K>60 D, surgical management accounted for 90.6%. A total of 618 eyes had improved BCVA at the final follow-up point (>18mo, P<0.001). When steep K was <52 D, the BCVA in the RGP group was better than those with lamellar keratoplasty (LKP; P=0.028). When steep K was >52 D, the BCVA and topographic astigmatism outcomes showed no differences among the treatment groups. When steep K was >60 D, the BCVA in eyes treated with LKP was worse than those with steep K<60 D (P=0.025). The incidence of steep K progression in the RGP group was higher in advanced group (20.0% vs 10.8%, P=0.019). The probability of future keratoplasty in RGP was higher in advanced group (14.8% vs 7.0%, P=0.027). The incidence of steep K progression in the corneal collagen crosslinking (CXL) group was higher in advanced group (32.3% vs 8.5%, P=0.007). Multivariate logistic regression revealed the following related factors for treatment options: steep K [odds ratio (OR)=1.208, 95%CI: 1.052-1.387], TA (OR=1.171, 95%CI: 1.079-1.270), and TCT (OR=0.978, 95%CI: 0.971-0.984). The level of steep K, TA, and TCT all relates to the treatment choices of both keratoplasty and non-keratoplasty, while steep K provided the highest diagnostic accuracy (AUC=0.947, P<0.001). CONCLUSION: Steep K is an important grading treatment indicator. When steep K is <52 D, RGP lenses should be recommended. It is the best time for LKP when the steep K ranges from 52 to 60 D.