Abstract
Purpose :
The tear film, one of the eye’s optical media, can be affected by IOP lowering medications. Its integrity is of paramount importance for generating reliable and reproducible Optical Coherence Tomography (OCT) images and for the assessment of disease progression. OCT built in quality indexes (IQIs) are accepted as an objective measurement of image signal-to-noise ratio. Several lacrimal substitutes are currently used to mitigate the effect of anti-glaucoma drops in symptomatic patients. In particular, it has been demonstrated that Trehalose/Hyaluronic acid has a protective effect on corneal and conjunctival epithelial cells. In this study, we sought to compare the OCT IQI before and after the topical application of Trehalose/Hyaluronic acid in glaucoma patients.
Methods :
100 consecutive patients treated with prostaglandin analogs (28 unpreserved and 72 preserved drops) attending the glaucoma clinic at the Western Eye Hospital in London have been assessed using spectral domain OCT before and 5 minutes after instillation of Trehalose/Hyaluronic (TH) eye drops (Thealoz Duo®, Thea, Clermont-Ferrand, France). OCT scanning protocols included the Posterior Pole scan which was used for the analysis. Average image quality for each scan was extrapolated from the built-in software of the OCT device and compared before and after TH application. All data are expressed as mean ± SD. P<0.05 was considered as significant.
Results :
A significant improvement of the IQI was observed after TH application (p<0.001) (Table1). Automatic layer segmentation also improved after TH application (1.45% VS 0.5% of errors). All other parameters did not show any significant difference (Table1). Main reason for recurrent segmentation error was due to lens opacity.
Conclusions :
This study shows for the first time that topical TH improves OCT IQI and reduces layer segmentation errors. It is well known how important these two parameters are for accurate and reliable glaucoma progression analysis. We propose that TH has a direct effect on conjunctival and corneal epithelial cells, over and above its lubricating properties. Although, this study was conducted using one specific lacrimal substitute and no head-to-head comparison was performed, we believe that corneal lubrication should be considered as a standard procedure before OCT scans. Further long-term studies are needed to confirm our results.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.