Hongda Zhang,1,* Yifan Qi,1,* Jiayan Chen,1 Guanghao Qin,1 Ling Xu,1 Wei He,1 Sile Yu,1,2 Huixin Che,1 Emmanuel Eric Pazo1 

1Department of Ophthalmology, He Eye Specialist Hospital, Shenyang, Liaoning, People’s Republic of China; 2School of Public Health, He University, Shenyang, Liaoning, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Huixin Che; Emmanuel Eric Pazo, Department of Ophthalmology, He Eye Specialist Hospital, No. 128 North Huanghe Street, Shenyang, Liaoning, 110034, People’s Republic of China, Email chehuixin@163.com; ericpazo@outlook.com

Purpose: The objective of this study was to assess the effectiveness of intense pulsed light (IPL) therapy in individuals diagnosed with glaucoma and dry eye disease (DED).
Methods: This randomized control study recruited 22 individuals diagnosed with glaucoma, ranging in age from 33 to 82 years. These participants were undergoing treatment with hypotensive eyedrops and had clinical indications and subjective complaints associated with dry eye. Each patient underwent three sessions of IPL therapy in one eye, while the contralateral eye served as the control eye (CT). The following parameters were assessed at three time points: baseline, week-2, and week-4. These parameters include non-invasive breakup time (NITBUT), tear meniscus height (TMH), conjunctivocorneal epithelial staining score (CS), tear film lipid layer (TFLL), meibomian gland expressibility score (MGEx), Schirmer I test, ocular bulbar redness score (OBRS), and ocular surface disease index (OSDI). Intraocular pressure (IOP), best-corrected visual acuity (BCVA), and corneal endothelial cell count (ECC) were assessed for safety. The clinical trial was registered on 25/12/2023 at ClinicalTrials.gov website (NCT06158984).
Results: Comparing baseline and 4-week measurements revealed that the IPL group found significant improvements in NITBUT (IPL: 8.74± 2.60 sec. vs CT: 5.76± 1.75 sec. p< 0.01), TMH (IPL: 0.23± 0.05mm vs CT: 0.19± 0.06mm, p=0.011), C.S. (IPL: 1.14± 0.56 vs CT: 1.95± 1.17, p=0.005), TFLL (IPL: 2.91± 2.91 vs CT:3.36± 0.58, p=0.047), MGEx score (IPL: 1.14± 0.35 vs CT: 1.45± 0.51, p=0.020) and OSDI scores (IPL: 31.77± 15.59 vs 50.59± 21.55, p=0.002) significantly improved. Conversely, other parameters showed no significant improvements (p> 0.05).
Conclusion: The progression of ocular surface disease in individuals using topical anti-glaucoma medication may worsen if the condition is not addressed. Nevertheless, IPL therapy has the potential to result in significant improvements in both objective and subjective measures of dry eye. Best-corrected visual acuity, endothelial cell count, and intraocular pressure were determined to be within the permitted limits. No adverse events were reported during the course of the study.
Plain Language Summary: The results show that people who use topical medicines to treat glaucoma may get worse eye surface disease if they do not treat the problem. IPL treatment, on the other hand, can make a big difference in both objective and subjective dry eye tests. The vision, endothelial cell count, and the pressure inside the eye were all found to be within normal limits after the IPL treatment. Even though the people in our study had glaucoma and had been taking glaucoma medicine for it for a year and the fact that the symptoms last for a long time may also change the results. Also, DED caused by glaucoma medication is complicated, with a lot of different symptoms and signs, even in the same stage. Also, subjective complaints may not match up with clinical signs. The type, amount, and length of anti-glaucoma drugs may have affected the results.

Keywords: glaucoma, intense pulsed light, dry eye, meibomian glands, glaucoma-related dry eye