Simple innovations in refractive surgery: modified techniques to measure implantable collamer lens (ICL) vault

Session Details

Session Title: Anterior Segment Imaging

Session Date/Time: Monday 16/09/2019 | 14:00-16:00

Paper Time: 15:36

Venue: Free Paper Forum: Podium 4

First Author: : R.Mukhija INDIA

Co Author(s): :    N. Sharma   A. Kishore   T. Makwana   N. Gupta   A. Pujari                 

Abstract Details

Purpose:

To describe the novel techniques of measuring implantable collamer lens (ICL) vault using a smartphone-macro lens combination and using a modified posterior segment OCT (MPOCT), and to compare the values with a standard anterior segment OCT (ASOCT).

Setting:

Institutional; pilot observational study. Patients who had come for regular follow up post ICL surgery willing to consent were included in the observation.

Methods:

In the first technique, 10 eyes images were taken using smartphone-macro lens combination from the temporal side (30 degrees angulation) with the patient seated on slit lamp for routine examination. The pictures with the best defined landmarks (between posterior surface of ICL and the anterior capsule) were then transferred onto image J software to quantify the vaulting. In the second technique, using MPOCT [modified by mounting a 20 dioptre lens (Volk Optical Inc) along its aperture], vaulting was quantified in 16 eyes. In addition, vaulting was independently quantified using ASOCT in all 26 eyes by a second observer for comparison.

Results:

The mean smartphone-macro lens combination derived vault was 276.6±103.58 microns and the ASOCT measured vault was 599.8±177.85 microns, with a mean difference of 323.2±98.16 microns between the two methods at 95% confidence interval with a correlation coefficient of r=0.888. The difference could be mainly due to the angulation of smartphone during image acquisition. In the second method, the mean ICL vault on ASOCT and MPOCT was 586.81±161.24 microns and 596.62±162.79 microns respectively. On paired t-test, at 95% confidence interval, a mean difference of 9.81 microns was noted [p=0.0025, Pearson correlation coefficient of r=0.99]

Conclusions:

Both smartphone-macro lens combination and MPOCT techniques are simple, effective, repeatable and reliable methods to ICL vaulting quantification in absence of sophisticated equipment.

Financial Disclosure:

None