# Effects of Intense Pulsed Light Treatment on Dry Eye Disease After Keratorefractive Surgery: A Retrospective Cohort Study

## TL;DR

This study found that IPL treatment for dry eye disease is less effective in people who previously had keratorefractive surgery compared to those who did not.

## Contribution

The study is the first to compare IPL treatment outcomes for dry eye disease in individuals with and without prior keratorefractive surgery.

## Key findings

- Non-KRS individuals showed significantly better improvement in tear break-up time after IPL treatment.
- KRS individuals had more risk factors for poor IPL treatment outcomes, including low tear meniscus height and high ocular surface staining.
- DED symptoms improved more in non-KRS individuals compared to those with prior KRS.

## Abstract

Purpose: This study aimed to evaluate the therapeutic outcome of intense pulsed light (IPL) treatment in individuals with dry eye disease (DED) who received previous keratorefractive surgery (KRS).

Methods: A retrospective cohort study was conducted, and individuals who received IPL treatment were enrolled. Then, the individuals were categorized according to whether they underwent KRS, with a total of 11 and 35 eyes enrolled in the KRS and non-KRS groups, respectively. The primary outcomes were non-invasive tear break-up time (NITBUT), the Schirmer I test, ocular surface staining, and DED symptoms. A generalized linear model was used to evaluate the difference in treatment outcomes between the two groups.

Results: Six months after the IPL treatment, the post-treatment NITBUT was significantly higher in the non-KRS group than the KRS group (P < 0.001). Regarding the trend of DED improvement, NITBUT (P < 0.001) and ocular surface staining (P = 0.001) presented a better improvement in the non-KRS group. In regard to pre-treatment risk factors for poor response after IPL treatment, low NITBUT, low TMH, high ocular surface staining, and multiple DED-related symptoms correlated to poor treatment outcome in the KRS population (all P < 0.05). On the other hand, low NITBUT and high ocular surface staining were associated with poor treatment outcome in the non-KRS population (both P < 0.05).

Conclusions: Individuals with DED that previously underwent KRS presented a lower NITBUT and ocular surface staining recovery after IPL treatment compared to the non-KRS DED individuals, and KRS individuals have more risk factors for poor outcomes after IPL. Alternative DED treatment may be considered for the population with previous KRS.