Dr. Tanvi Dilip Madia, Dr. Smita Singh, Dr. Shukla A K, Dr. Puja Hingorani-Bang, Dr. Sneha Gupta
Accurate axial length( AL) measurement is very important for correct IOL Power determination.Errors in preoperative axial length is the most significant error in IOL power calculation.Nuclear density too is known to change the AL measurements.
This study was carried out in Eye Ward of a tertiary hospital after obtaining clearance from IEC .AL of 300 eyes of 150 consecutive bilateral cataract patients admitted for surgery was measured by optical biometry first,followed by ultrasonic(US) A scan and compared.
Mean AL of all eyes by Optical biometry was 23.272mm and 23.254mm by US biometry. Paired t test showed no significant difference in the mean AL. In eyes with NS grade1 no significant difference was found in the two methods (p > 0.05) but in NS grades 2 & 3 difference in two methods was highly significant (p=0.00) In grade 4 NS we could not obtain optical biometric readings.
Optical biometry is comparable to US in NS1 and is significantly higher in NS2 .