The SRK/T formula for IOL power calculation is most accurately described as which type of formula?
- A Second-generation theoretical formula
- B Ray-tracing formula
- C Third-generation regression formula with theoretical modification ✓
- D Fourth-generation formula using anterior segment OCT
Correct answer: C. Third-generation regression formula with theoretical modification
Explanation
SRK/T (T for theoretical) is a third-generation formula that combines an empirical regression approach with theoretical optical principles; it uses axial length, keratometry, and a personalized A-constant. Second-generation formulas include SRK II. Ray-tracing and newer vergence formulas such as Barrett Universal II and Kane represent newer generations. Fourth-generation formulas like Holladay 2 incorporate additional biometric variables beyond the basic three.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.