- Home
- Medical news & Guidelines
- Anesthesiology
- Cardiology and CTVS
- Critical Care
- Dentistry
- Dermatology
- Diabetes and Endocrinology
- ENT
- Gastroenterology
- Medicine
- Nephrology
- Neurology
- Obstretics-Gynaecology
- Oncology
- Ophthalmology
- Orthopaedics
- Pediatrics-Neonatology
- Psychiatry
- Pulmonology
- Radiology
- Surgery
- Urology
- Laboratory Medicine
- Diet
- Nursing
- Paramedical
- Physiotherapy
- Health news
- Fact Check
- Bone Health Fact Check
- Brain Health Fact Check
- Cancer Related Fact Check
- Child Care Fact Check
- Dental and oral health fact check
- Diabetes and metabolic health fact check
- Diet and Nutrition Fact Check
- Eye and ENT Care Fact Check
- Fitness fact check
- Gut health fact check
- Heart health fact check
- Kidney health fact check
- Medical education fact check
- Men's health fact check
- Respiratory fact check
- Skin and hair care fact check
- Vaccine and Immunization fact check
- Women's health fact check
- AYUSH
- State News
- Andaman and Nicobar Islands
- Andhra Pradesh
- Arunachal Pradesh
- Assam
- Bihar
- Chandigarh
- Chattisgarh
- Dadra and Nagar Haveli
- Daman and Diu
- Delhi
- Goa
- Gujarat
- Haryana
- Himachal Pradesh
- Jammu & Kashmir
- Jharkhand
- Karnataka
- Kerala
- Ladakh
- Lakshadweep
- Madhya Pradesh
- Maharashtra
- Manipur
- Meghalaya
- Mizoram
- Nagaland
- Odisha
- Puducherry
- Punjab
- Rajasthan
- Sikkim
- Tamil Nadu
- Telangana
- Tripura
- Uttar Pradesh
- Uttrakhand
- West Bengal
- Medical Education
- Industry
Kane or Barrett Universal II Formulae best for IOL power calculation in elderly: Study
Predictive accuracy within 0.5D is 72% with both Kane and Barrett Universal II formulae
A study conducted by researchers from Shiley Eye Institute, University of California San Diego, USA has shown that elderly patients undergoing cataract surgery are likely to have most predictable refractive outcome when IOL power calculation is done using the Kane or the Barrett Universal II formula.
The study has been published in the Journal of Cataract and Refractive Surgery.
Cataract surgery has now become almost a refractive procedure due to increasing patient demand for spectacle independence post-surgery. Accurate biometry and IOL power calculation formula are essential to achieve the same. Extensive research has been going on in the field of IOL power calculation formulae but predictability of refractive outcome over a wide range of axial length and keratometry still remains a challenge.
The latest formula being studied is the Kane formula. Developed in 2017, this formula is based on theoretical optics and incorporates both regression and artificial intelligence components. The main focus of the formula is to reduce the errors seen at the extremes of the various ocular dimensions. It incorporates multiple variables like axial length, keratometry, anterior chamber depth, lens thickness, central corneal thickness and patient gender.
A retrospective cohort study was conducted by the researchers with data collected from 90 eyes of 90 patients who had undergone uneventful cataract surgery with SN60WF intraocular lens implantation. All patients were elderly, aged 75 years or above. The first operated eyes of the patients having uncorrected distance visual acuity of 20/30 or better were included in the study. All eyes had axial length between 22-26mm. Prediction errors were calculated for Barrett Universal (BU) II, Haigis, Hoffer Q, Holladay 1, SRK/T and Kane formulae. Two subgroups were formed based on the age: Subgroup I (75-84 years) and Subgroup II (>85 years) and a separate analysis was also done for each group.
The results were as follows
- The predictive accuracy within +0.5D was significantly higher with the Kane and the Barrett Universal II formulae as compared to Hoffer Q, Holladay 1 and SRK/T.
- Percentage of eyes with prediction errors within ±0.50 D was 72% with each of two formulae
- Rate of predictability within ±1.00 D was 87% to 92% with no significant differences between the different formulas.
- Rate of predictability within ±0.25 D was 31% to 38% with no significant differences between the different formulae
- Subgroup analysis showed better predictability of all formulae in the younger age group.
- According to the authors, there is no available literature evaluating the Kane formula exclusively in the elderly population. In this study, the Kane formula was found to be of equal accuracy to the Barrett Universal II and superior to the Hoffer Q, Holladay 1, and SRK/T formulas.
"Elderly patients undergoing cataract extraction might have less predictable refractive outcomes. This group could benefit from IOL calculations with the Kane and the Barrett Universal II formulas." conclude the authors.
For further reading, please click on the link
Dr Sudha Seetharam is an Ophthalmologist practising at Laxmi Eye Institute, Maharashtra. She has received her MBBS from Medical College, Kolkata and M.S (Ophthalmology) from Maulana Azad Medical College, New Delhi. Writing and teaching are her passions. She is the author of the book “Self-assessment and Review of Ophthalmology” meant for MBBS students preparing for NEET PG Medical Entrance examination. She is a faculty of Ophthalmology at various teaching institutes and online platforms which train students for NEET PG Medical Entrance examination. She has also authored the book “Beyond Medicine- Life Lessons Learnt as a Doctor” which describes the real life experiences of a doctor during internship in a government hospital.
Dr Kamal Kant Kohli-MBBS, DTCD- a chest specialist with more than 30 years of practice and a flair for writing clinical articles, Dr Kamal Kant Kohli joined Medical Dialogues as a Chief Editor of Medical News. Besides writing articles, as an editor, he proofreads and verifies all the medical content published on Medical Dialogues including those coming from journals, studies,medical conferences,guidelines etc. Email: drkohli@medicaldialogues.in. Contact no. 011-43720751