Official ESCRS | European Society of Cataract & Refractive Surgeons

 

Dysfunctional lens index: the future of refractive lens surgery?

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Session Details

Session Title: Presented Poster Session: New & Interesting I

Venue: Poster Village: Pod 3

First Author: : A.Koshy INDIA

Co Author(s): :    R. Shetty   L. Kaweri   G. Kundu                 

Abstract Details

Purpose:

Presbyopic patients unhappy with the frequent change in glasses prescription desire a satisfactory solution. Decision for keratorefractive vs lenticular procedures is made based on lens density changes. However none of the standard lens evaluation techniques take into account the quality of vision. We attempt to provide a novel index which could redefine the future of refractive lens surgery. This study aims to describe the dysfunctional lens index (DLI) in presbyopic age group and to test its correlation with lens density changes and quality of vision.

Setting:

A cross sectional observational study carried out at Narayana Nethralaya, a tertiary level superspeciality eye hospital, Bangalore, India.

Methods:

166 eyes of presbyopic patients (40-60 years) with best corrected distance and near visual acuity 20/20 and N6 were included in our study. Lens densitometry was assessed as per LOCS(Lens Opacity Classification System) III classification and Pentacam Nuclear staging(PNS) (Pentacam HR, Oculus, Germany) by two independent trainees using the anterior segment slit lamp photo. DLI, quality of vision parameters like Area under Curve (AUC) for Modulation Transfer Function (MTF),  Strehl’s ratio (SR) and internal aberrations on Itrace (Tracey Technologies, Houston, TX) were measured. Correlation between DLI and MTF, SR and internal aberrations was done.

Results:

In eyes with clear lens and average and maximum density as Pentacam Nuclear Staging 0, mean DLI was 7.8105 +/- 2.1658.  Abnormal lens index (considered as DLI < 7) was seen in 37.34% while significant lens changes ( considered as DLI < 5) was found in 10.24%. DLI had positive correlation with SR (r= 0.377, p=0.0), MTF (r= 0.382, p=0.0) and negative with internal aberrations (r=-0.730, p=0).

Conclusions:

DLI can be an objective indicator of the lenticular quality of vision in presbyopes. It provides us with a paradigm shift in assessing the lens functionality over just photographical comparison. It is a futuristic biomarker that enables us to determine the treatment options in presbyopes. Abnormal DLI directs us towards lens based treatment options. It can be used as an educational tool for counselling patients. It enhances the armamentarium of a refractive lens surgeon and can be a trailblazer to perform refractive lens surgery.

Financial Disclosure:

None

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