Which medication is a calcineurin inhibitor commonly used in ocular therapy to treat dry eye?

Which medication is a calcineurin inhibitor commonly used in ocular therapy to treat dry eye?

• A. Tacrolimus
• B. Cyclosporine
• C. Sirolimus
• D. Everolimus

Answer: (B)

Cyclosporine is a calcineurin inhibitor used in eye drops to treat dry eye because it directly reduces T-cell–driven inflammation on the ocular surface. It binds to cyclophilin, and this complex blocks calcineurin, preventing IL-2 transcription and T-cell activation. By dampening this inflammatory response, tear production and overall tear film stability improve over time, which is why cyclosporine ophthalmic emulsion (the common dry eye therapy) is used. The other options don’t fit as well: tacrolimus is another calcineurin inhibitor but is not the standard ocular therapy for dry eye, while sirolimus and everolimus inhibit the mTOR pathway, not calcineurin, so they aren’t used for this purpose.

Cyclosporine is a calcineurin inhibitor used in eye drops to treat dry eye because it directly reduces T-cell–driven inflammation on the ocular surface. It binds to cyclophilin, and this complex blocks calcineurin, preventing IL-2 transcription and T-cell activation. By dampening this inflammatory response, tear production and overall tear film stability improve over time, which is why cyclosporine ophthalmic emulsion (the common dry eye therapy) is used. The other options don’t fit as well: tacrolimus is another calcineurin inhibitor but is not the standard ocular therapy for dry eye, while sirolimus and everolimus inhibit the mTOR pathway, not calcineurin, so they aren’t used for this purpose.