According to me,
Cross-Linking is generally a safe procedure that's saved many patients from having to undergo corneal transplants as a result of their keratoconus or corneal ectasia. They work like help bars to enable the cornea to remain stable. The FDA endorsed corneal cross-connecting for keratoconus in 2016. At the present time, it's the main treatment that can prevent the condition from deteriorating.
The expense of a corneal cross-linking system for keratoconus or corneal ectasia can run from $2,500 to $4,000 per eye.
Is infection possible ? Is it possible that cross linking deteriorate cornea and it leads to corneal transplantation ?
No not dangerous, less dangerous than leaving the cornea alone if it is failing and the round shape turning into cone shape.