We observed the effectiveness of IPLT + MGXT over the traditional MGX in improving MGYSS, l-MGYSS, u-MGYSS, TBUT.
Compared to MGX, IPL combined with MGX is convenient, safe, and effective for the treatment of MGD-related dry eyes. Besides, the efficacy and maintenance time of IPL combined with MGX is better than MGX alone.17–22 One RCT included in our study validated that the effects of IPL-MGX on TUBT, plugging, vascularity, CFS score, and meibum grade in MGD can be maintained for 32 weeks.17 Another RCT showed that the l-MGYSS and SPEED scores of patients receiving IPL treatment could be significantly ameliorated until 9 months after treatment.21 Furthermore, a retrospective study indicated a significant improvement in TUBT and post-treatment satisfaction with the degree of dry eye syndrome symptoms for up to 3 years in patients treated with IPL-MGX 26. In terms of safety, no irreversible eyelid skin damage, anterior segment inflammatory reaction, iris depigmentation, ocular surface or fundus damage, visual acuity damage, and high intraocular pressure were not experienced in these studies,17, 18, 20, 22 whereas, Bei Rong et al.21 reported 5 patients had mild pain, burning during the IPL treatment.
The average annual direct cost of treating DED patients in the United States is US$783, with a range of US$757- US$809. 27 The results from a study involving 6 European countries (France, Germany, Italy, Spain, Sweden, and the United Kingdom) claimed that the total annual medical costs for treating 1,000 DED patients ranged from US$270,000 in France to US$1.1 million in the United Kingdom 28 Researchers from the Singapore National Eye Centre estimated the cost data of 54,052 patients and found that the total annual expenditure for dry eye treatment in 2008 and 2009 exceeded US$1.5 million. 29 The severity of MGD dictates the effect of treatment; henceforth, the annual cost of IPL treatment for different patients varies greatly. We make joint decisions by considering relevant factors (including the convenience of treatment time, the timing of intervention, etc.), which will help patients by improving the therapeutic outcome and reducing treatment costs.
Except for the heterogeneity in the CFS trial, our meta-analysis results substantiate the absence of heterogeneity among the trials. To investigate the influence of individual studies on the pooled estimates, each study in the meta-analysis was excluded in turn utilizing leave-one-out cross-validation. We observed that the heterogeneity of the CFS test came from the article by Rong et al.20 The source of heterogeneity was primarily attributed to the study population, selection criteria, and differences in treatment. For instance, first, the average age of trial participants ranged from 27 to 61 years. The age range was large, and the research subjects involved young people and the elderly, which was responsible for the differences in the results of different trials. Second, the inclusion criteria for the included trials were different. One trial followed 4 inclusion criteria, while other trials mentioned 2 to 4 inclusion criteria. Third, there was variation in the trial intervention methods used in the control group. For example, some trials employed sham IPL combined with MGX, whereas some trials used only MGX. Finally, the energy of IPL in the included trials ranged from 12 to 16 J/cm2 and the frequency also varied. Moreover, the upper eyelid and lower eyelid were treated simultaneously in this article by Rong et al.20
Nevertheless, this meta-analysis has some limitations that should be taken into consideration. First, the analyzed trials had significant differences regarding the characteristics of the patients. The mean age of the trial participants was 27 to 61 years and the energy of IPL in the included trials ranged from 12 to 16 J/cm2. All these may affect the efficacy of IPL in the treatment of MGD. Second, after sensitivity analysis, the difference in corneal fluorescein staining between the two groups was unstable. Therefore, this result should be interpreted with caution. Finally, the included trials compared two treatments for 3 months only. However, other non-RCT demonstrated that the effects of IPL may last for 3 years.26
In conclusion, this systematic review and meta-analysis indicate that IPL-MGX is more efficacious, which improves MGYSS, l-MGYSS, u-MYGSS, and TUBT than the MGX alone. Furthermore, this meta-analysis of 6 RCTs suggests the safety of IPL in the treatment of patients with MGD-related dry eye. Therefore, we recommend discussing the decision with the ophthalmologist to make an appropriate choice.