What is the best treatment option for Keratoconus (KC) in moderate to severe cases?

corneal crosslinking followed by laser or intacs, PKP is the final resort

Intacs if cornea thickness allowed 

The best treatment in moderate to severe cases is Collagen cross linking and corneal transplants in selected cases.

Crosslinking followed by corneal ring implantation.

PKP is the last choice..

in moderate to severe cases the best option is corneal ring with crosslinking.

In moderate keratoconus : cross linking with intracorneal ring segments implantation or there is another therapeutic alternative is a simulaneous photorefractive keratectomy (PRK) followed by corneal cross linking. 

When there is scars in stage 4, keratoplasty is the only therapeutic indication. It is better to perform deep anterior lamellar keratoplasty

The best treatment in moderate to severe cases is eximer laser and in some cases even corneal transplant.

In the initial and moderate Keratoconus we can get the stop of corneal stromal disease by Cross Linking procedure. In the advanced Keratoconus the best treatment is Dalk by femtolaser or by Big bouble procedure

if cornea clear , nearly ggod thickness and moderate kc , in this case cross linking aith or without intacs , but in sever k reading the option treatement is pkp 

Crosslinking with corneal ring and in severe cases corneal transplant.