Alternation of Lipidomic in the Meibomian Gland After Exposure to Intense Pulsed Light in Patients With Meibomian Gland Dysfunction and Suggestions for Applications of 3PM Medicine

doi:10.21203/rs.3.rs-771995/v1

Importance: Aside from the clinical index, there is no established criterion for assessing the effectiveness of intense pulsed light (IPL) in treating meibomian gland disease.

Objective：To determine if there is an association between changes in the meibum lipidomic profiles and alleviation of clinical signs in patients with meibomian gland dysfunction (MGD) who are treated with IPL. To provide predictive, preventive and and personalized medical programs for MGD patients.

Design: This is an observational Study. Patients were followed for up for 6 months from January 1, 2019.

Setting: This is a single center, human-oriented clinical and basic research study.

Participants: Adult patients, who were diagnosed with MGD and had not received any alternative treatments for at least 3 months, were enrolled in the study.

Exposures: Each patient received a series of three treatments at 3-week intervals. The meibum was collected before the first treatment (T0) and the third treatment (T2). All enrolled patients completed the whole examination and treatment. The meibum of randomly assigned 26 patients and 10 healthy volunteers was chosen for performing the lipid analysis using LC-MS/MS.

Main Measures: The following information from each patient was recorded: tear break-up time (BUT), average tear BUT, tear meniscus height, assessment of the lid margin, bulbar redness, meibomian gland opening position, corneal fluorescein staining, meibomian gland drop, meibomian gland expressibility, and meibum quality.

Results: A total of 191 patients’ right eyes were enrolled in the study, including 95 females (49.7%) and 96 males (50.3%), with a median age of 53 years (range: 28–85 years). IPL increased the BUT (P<0.0001, t=7.9, df=380), average tear BUT (P<0.01, t=2.774, df=374.5), and tear meniscus height (P<0.01, t=2.642, df=367.1). At the same time, IPL improved bulbar redness (P<0.0001, t=12.95, df=380) and corneal fluorescein staining (P<0.0001, t=4.147, df=380). Furthermore, following IPL treatment, the meibomian gland expressibility (MGE) and meibum quality were significantly improved (from 1.342±0.05815 to 0.9354±0.03922, P<0.0001, t=5.798, df=380 and from 1.266±0.04969 to 0.8639±0.03318, P<0.0001, t=6.733, df=380, respectively). Lipidomic analysis of the meibum characterized the changes in lipid profiles induced by IPL.

Conclusion: IPL treatment offers a novel approach to markedly improve the treatment of patients with MGD due to correction of altered lipid profiles. The changes in lipid expression profiles are potential indexes to evaluate the therapeutic effectiveness of IPL treatment or other treatments on MGD. The lipid changes that are pertinent include: LPC(18:2)+HCOO, OAHFA(18:1/34:1)-H, TG(16:0/18:2/20:5)+H, and etc.. Therefore, accurate evaluation of the changes of lipid expression profile in patients with MGD can be used as a predictive, preventive, and personalized medical method.

Health Economics & Outcomes Research

Dry eye

meibomian gland dysfunction

intense pulsed light

lipidomic of meibum

Question: What are the effects of IPL treatment on the clinical assessment and the lipidomic profile in patients with meibomian gland disease?

Findings: In MGD patients who received IPL treatment, the improvements in the assessments of the clinical syndrome were highly related with alterations in the meibum lipidomic profiles.

Meaning: The changes in the lipids are potential indexes to evaluate the therapeutic effect of IPL or other treatments on MGD. The lipid changes that are pertinent include: LPC (18:2) +HCOO, OAHFA (18:1/34:1)-H, TG (16:0/18:2/20:5) +H, and etc..

Dry eye (DE) is becoming the most common ocular surface disease worldwide. As defined by the International Dry Eye Workshop II, DE is a multifactorial disease of the ocular surface characterized by loss of homeostasis of the tear film, and accompanied by ocular symptoms. In this condition, tear film instability and hyperosmolarity, ocular surface inflammation and tissue damage, and neurosensory abnormalities play etiological roles¹. Disruption of the homeostasis of the ocular surface microenvironment is the main reason leading to DE. The meibomian gland (MG) is one of the components of the ocular surface microenvironment and its secretion plays an important role in tear film homeostasis².

Meibomian gland dysfunction (MGD) is the most common cause of DE worldwide. According to the definition of The International Workshop on Meibomian Gland Dysfunction, MGD is a chronic, diffuse abnormality of the meibomian glands, commonly characterized by terminal duct obstruction and/or qualitative/quantitative changes in the glandular secretion. It may result in alteration of the tear film, symptoms of eye irritation, clinically apparent inflammation, and ocular surface disease³.

Epidemiological surveys have shown that the prevalence of MGD in Europe has reached 21.9%^4,5, and that in Asian populations it is as high as 69.3%^6-9. At present, there is no uniform diagnostic standard for MGD¹⁰. The criteria for arriving at a diagnosis are not definitive and limited to determining if: (1) the glandular glands are absent; (2) there are abnormalities between the temporal margin and MGs; and (3) the volume and quality of MG secretions are altered. Any of the above signs in combination with ocular symptoms are indicative of MGD. Due to the lack of symptomatic specificity assigned to MGD, it is often misdiagnosed and mistreated. Long-term MG lesions can cause inflammatory reactions in the ocular surface, which in turn lead to corresponding changes in the cornea and conjunctiva¹¹. In severe cases, visual acuity declines, resulting in poor prognosis. These limitations in arriving at accurate diagnosis is prompting increasing attention by researchers in gaining insight into the pathophysiology underlying MGD.

Intense pulsed light (IPL) is a noncoherent polychromatic light source with a broad wavelength spectrum of 500–1,200 nm^12,13. As an established commercial technology, IPL treatment is broadly used in diseases involving facial rosacea. It has been shown that IPL is effective for the treatment of the eyelid sebaceous gland, also termed MG^14-16. Thus, IPL is a promising new therapy for MGD. Prior to the development of IPL, the treatment against MGD or DEs involved warming and massage¹⁷. Currently, IPL treatment is regarded as a more time-efficient and effective method to ameliorate the symptoms of DE¹⁸. Although the efficacy and safety of IPL had been confirmed¹⁹, the most significant changes in the rouge composition before and after exposure to IPL remain unclear.

The palpebral lipids are mainly composed of wax lipids, cholesterol lipids, free fatty acids, phospholipids, and a small amount of protein. More than 100 components of palpebral lipids have been found, and hundreds of subtypes have not been identified thus far^20-22. In this study, a comprehensive evaluation of clinical signs and changes in the lipid composition of meibum was conducted in patients with MGD after at least three exposures to IPL. A comparison of clinical assessment and alteration of the meibum was also conducted in patients treated with IPL and those without MGD. The results of this study will be helpful in understanding the mechanisms through which IPL can effectively treat MGD, besides providing insightful data for future studies. Through our research, we can provide predictive, preventive and and personalized medical services for MGD patients.

Patients

Adult patients, who were diagnosed with MGD and had not received any alternative treatments for at least 3 months, were enrolled in the study. The inclusion criteria were: diagnosis of MGD according to the Japanese MGD diagnostic criteria (Bron and Tiffany 2004), including ocular symptoms, plugged gland orifices, vascularity of lid margins, irregularity of lid margins, and decreased meibum quality and quantity. The exclusion criteria were: previous ocular surgery or trauma; blepharal dysraphism; history of blepharal and periorbital skin disease within 1 month prior to enrollment; acute inflammation; rheumatic immune systemic diseases; excessive sun exposure within 1 month prior to enrollment; history of herpes zoster infection; pregnancy; and use of photosensitive drugs/foods.

Informed consent was provided by all patients following explanation of the nature and possible consequences of the study. This study was approved by the Institutional Review Board of the Xin Hua Hospital of Shanghai Jiao Tong University School of Medicine (Shanghai, China) and was registered with the Chinese Clinical Trial Registry prior to enrollment of the first patient. This study adhered to the tenets of the Declaration of Helsinki. All examiners were blinded to the treatment group. The study was enlisted in the clinical trial registry (trial registration no.: ChiCTR2000033454).

IPL treatment

Each patient received a series of three treatments at 3-week intervals. The patients had to use Proparacaine Hydrochloride Eye Drops at least twice prior to each treatment. A modular laser multi-application platform (Quantum™, Lumenis, USA) was used to administer treatment to the periorbital area. During the IPL procedure, patients were required to wear opaque goggles, and the coolant was applied around the eyelids under both eyes. Makeup and contact lenses were removed before treatment. Depending on patient tolerance, each subject in the patient group received 2–3 light pulses. The intensity of IPL treatment (12~15 J/cm²) depending on the Fitzpatrick skin with a 590-nm filter.

Clinical assessment

Visual acuity and intraocular pressure were recorded in the case-report form. The Standard Patient Evaluation of Eye Dryness questionnaire was completed by each patient. Schirmer 1 test, corneal staining, meibum quality and meibomian gland expressibility (MGE), lid margin abnormality, bulbar redness, MG opening position, and corneal fluorescein staining were measured through slit lamp microscopy. A noncontact infrared meibography system was used to assess tear BUT, MG dropout, and tear meniscus height.

Meibum acquisition

The use of makeup, artificial tears, and cleaning the rim more than 3 hour prior to the collection of the material was prohibited. After exposure to IPL, proparacaine hydrochloride eye drops were used again and the material was collected. The use of plastic products during sample preparation and experimentation was avoided to prevent contamination of the rouge. The steps performed for the collection of the materials were as follows: 1) the MG pressing method was used to squeeze out the secretions of the MGs with a MG expressor forceps – this is achieved by placing the thumb of one hand under the lower eyelid, squeezing the rim and rapidly pulling down, and squeezing out the secretion of the MG (the same method was used to remove the rouge from the upper eyelid); 2) a medical cotton swab was used to scrape the MG secretions, the cotton swab was placed it in a cryotube, and stored at −80°C until further analysis. The amount of rouge collected in this study was 1.77±0.29 mg.

Ultrahigh pressure liquid chromatography liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)

LC separation using CSH C18 column (1.7 µm, 2.1 mm × 100 mm, waters) was selected to perform reverse phase chromatography. The lipid of meibum was re-dissolved in 200 µL 90% isopropanol/ acetonitrile, than centrifuged at 14,000 xg for 15 min, finally 3 µL of the sample was selected for injection. Solvent A: acetonitrile–water (6:4, v/v) with 0.1% formic acid and 0.1Mm ammonium formate. Solvent B: acetonitrile–isopropanol (1:9, v/v) with 0.1% formic acid and 0.1mm ammonium formate. The initial mobile phase was 30% solvent B at a flow rate of 300 μL/min. It was held for 2 min, and then linearly increased up to 100% solvent B in 23 min, followed by equilibrating at 5% solvent B for 10 min. Mass spectra was acquired by Q-Exactive Plus in positive and negative mode, respectively. ESI parameters were optimized and preset for all measurements as follows: Source temperature, 300 °C; Capillary Temp, 350 °C, the ion spray voltage was set at 3,000V, S-Lens RF Level was set at 50% and the scan range of the instruments was set at m/z 200–1800.

“Lipid Search” is a search engine for the identification of lipid species based on MS/MS math. LipidSearch contains more than 30 lipid classes and more than 1,500,000 fragment ions in the database. Both mass tolerance for precursor and fragment were set to 5 ppm.

Statistical analysis

Data were analyzed using the SPSS version 22.0 (IBM Corp., Armonk, NY, USA) software. Continuous intergroup variables were analyzed using an independent t-test, and pretreatment and continuous intragroup variables were analyzed with a paired t-test. Categorical intergroup variables were analyzed with the nonparametric Kruskal–Wallis test, and intragroup analysis of categorical variables was performed using the nonparametric Wilcoxon signed-rank test. Correlations between normally distributed values and non-normally distributed values were analyzed with the linear Pearson correlation coefficient and the Spearman correlation coefficient respectively. P<0.05 denoted statistical significance.

Patient demographics

A total of 191 patients’ right eyes were enrolled in the study, including 95 females (49.7%) and 96 males (50.3%), with a median age of 53 years (range: 28–85 years). We collected the meibum before the first treatment (T0) and the third treatment (T2) All enrolled patients completed the whole examination and treatment; there was no pain or any discomfort reported during the tests. Among the patients, we chose 26 patients randomly to do the lipid analysis using LC-MS/MS. And we also recruited 10 volunteers who had no ocular surface disease and other systemic disease (The work plan is illustrated as follows) (Table 1).

Tear film and ocular surface analysis

Tear meniscus height was used to evaluate the quantity of the tear film. Following treatment with IPL, the tear meniscus height was markedly increased from 0.1658±0.003853 to 0.1818±0.004657 (P<0.01, t=2.642, df=367.1). At the same time, the BUT and average tear BUT (aBUT) were used evaluated the quality of the tear film; both increased following treatment from 3.90±0.10 to 5.02±0.10 (P<0.0001, t=7.9, df=380) and from 4.93±0.12 to 5.36±0.10 (P<0.01, t=2.774, df=374.5), respectively. Intriguingly, the corneal fluorescein staining (FL) of corneal epithelium integration and the bulbar redness of conjunctival (CR) inflammation were markedly improved, The FL score decrease from 0.43 ± 0.05 to 0.20 ± 0.03 (P<0.0001, t=4.147, df=380) and the CR scorce reduce from 1.24±0.04 to 0.59±0.03 (P<0.0001, t=12.95, df=380), respectively (Table 2).

Eyelid margin abnormalities

As previously reported, IPL may improve the eyelid margin; our findings suggest that there was no statistically significant difference after the IPL treatment in terms of orifice abnormality and MG dropout (from 0.9686±0.04571 to 0.9319±0.04625, P=0.5733, t=0.5636, df=380 and from 1.314±0.05266 to 1.314±0.05266, P>0.9999, t=0, df=380, respectively) (Table 2).

MGE and meibum quality

The scores of MGE and meibum quality were used to evaluate the quality and expressibility of the meibum. Following IPL treatment, the meibum changes from solid state to liquid state and becomes clear and easy to eliminate, the MGE score and meibum quality score were significantly decreased (from 1.34±0.06 to 0.94±0.04, P<0.0001, t=5.798, df=380 and from 1.27±0.05 to 0.86±0.03, P<0.0001, t=6.733, df=380, respectively) (Table 2).

Lipid metabolism of MG

As previously reported, IPL shows great therapeutic potential for patients with MGD and ocular surface diseases. It is well established that MGs are rich in lipids. The meibum and lipids of the MG were collected to perform a lipid analysis using LC-MS/MS. A total of 323 lipid species were identified and most of them were rich in triglyceride (TG, n=127), ceramide (Cer, n=86), phosphatidylcholine (PC, n=29), sphingomyelin (SM, n=28), simple Glc series G1 (CerG1, n=23), sphingosine (SO, n=9), lysophosphatidylcholine (LPC, n=8), lysophosphatidylethanolamine (LPE, n=8), monogalactosyldiacylglycerol (MGDG, n=5), phosphatidylserine (PS, n=5), digalactosyldiacylglycerol (DGDG, n=4), (O-acyl)-1-hydroxy fatty acid (OAHFA, n=4), phosphatidylethanolamine (PE, n=4), digalactosylmonoacylglycerol (DGMG, n=3), wax ester (WE, n=3), simple Glc series G2 (CerG2, n=2), coenzyme (CO, n=2), lysophosphatidylglycerol (LPG, n=2), phosphatidylglycerol (PG, n=2), diglyceride (DG, n=1), lysophosphatidylinositol (LPI, n=1), lysophosphatidylserine (LPS, n=1), lysosphingomyelin (LSM, n=1), monogalactosylmonoacylglycerol (MGMG, n=1), phosphatidylinositol (PI, n=1), and stigmasterol ester (StE, n=1) (Fig. 1A). When we compared the T0 to control and T2 to T0, there were significant differences observed between the groups in lipid quality, as shown by the volcano plot (Figs. 1B and C). Moreover, when we compared the T2 to T0, most of the different lipids were decreased in the former; when we compared the T0 to control group, most of the different lipids were increased in T0.

At the individual lipid compound level, the increased lipids in T0 (i.e., CerG1, CerG2, Co, DG, LPC, LPE, LPG, LPI, LPS, OAHFA, StE, and TG) were decreased following IPL treatment (T2) (Figs. 2A1–A12). There were no significant differences in Cer, DGDG, LSM, MGDG, PG, PI, PS, SM, SO, and WE that increased in T0 and T2 (Figs. 2B1–B10). The decrease in DGMG and MGMG in T0 could be reversed by IPL treatment (T2) (Figs. 2C1 and C2). Furthermore, the levels of PC and PE in T2 were higher than those measured in T0 (Figs. 2D1 and D2).

A total of 41 lipid species were significantly different in patients with MGD (T0) versus healthy controls. The different lipids were rich in TG (6/41), SM (6/41), Cer (6/41), OAHFA (3/41), PC (2/41), DGMG (2/41), SO (3/41), PS (2/41), LPE (1/41), LSM (1/41), CerG1 (1/41), CO (1/41), MGMG (1/41), and WE (1/41) (Table 3). Following IPL treatment (T2), 24 lipid species were significantly different compared with T0: TG (10/24), LPC (6/24), OAHFA (4/24), Cer (2/24), SM (1/24), and PE (1/24) (Table 4). The change of the lipid metabolic pattern was highly related to the improvement of the clinical index (Fig. 3). The correlation was rich in BUT1, CR and meibum quality and some lipids were cross related with them. LPC (18:2)+HCOO, OAHFA(18:1/34:1)-H, OAHFA(18:1/32:2)-H, OAHFA(18:1/32:1)-H, TG(16:0/18:2/20:5)+H, LPC(18:2)+H, OAHFA(18:1/30:1)-H, LPC(18:1)+H, TG(25:0/16:1/18:1)+NH4, TG(16:1/18:1/18:2)+NH4, TG(26:1/18:1/18:1)+NH4 and TG(18:1/18:2/20:5)+H were highly corelated with the change in the meibum quality. Cer(d17:0/2:0)+H, OAHFA(18:1/34:1)-H, OAHFA(18:1/32:1)-H, OAHFA(18:1/32:2)-H, TG(16:0/18:2/20:5)+H and OAHFA(18:1/30:1)-H were related with the change in the CR. The change of BUT1 may be induced by OAHFA(18:1/32:2)-H, OAHFA(18:1/34:1)-H, OAHFA(18:1/30:1)-H and OAHFA(18:1/32:1)-H. Cer(d18:1/18:0)+HCOO and Cer(d17:0/2:0)+H were related with the aBUT. TH was highly related with Cer(d18:1/18:0)+HCOO, SM(d36:1)+H, LPC(16:0)+HCOO, LPC(18:0)+HCOO and TG(18:1/18:2/20:5)+H. TG(16:0/18:2/20:5)+H was highly related with the MGE. Notably, 13 lipids were significantly increased in T0, whereas they were decreased following IPL treatment. The different lipids were OAHFA(18:1/34:1)-H(C₅₂H₉₇O₄), OAHFA(18:1/32:1)-H(C₅₀H₉₃O₄), OAHFA(18:1/32:2)-H(C₅₀H₉₁O₄), LPC(18:1)+H(C₂₆H₅₃O₇N₁P₁), LPC(18:0)+HCOO(C₂₇H₅₅O₉N₁P₁), LPC(18:1)+HCOO (C₂₇H₅₃O₉N₁P₁), LPC(16:0)+HCOO(C₂₅H₅₁O₉N₁P₁), LPC(18:2)+H(C₂₆H₅₁O₇N1 P1), TG(26:0/16:0/18:1)+Na(C₆₃H₁₂₀O₆Na₁), TG(18:1/18:2/20:5)+H(C₅₉H₉₉O₆), TG(16:0/18:2/20:5)+H(C₅₇H₉₇O₆), TG(16:1/18:1/18:2)+NH4 (C₅₅H₁₀₂O₆N₁), and Cer(d17:0/2:0)+H(C19 H40 O3 N1) (Table 5). We found that Cer(d18:1/18:0)+HCOO (C₃₇H₇₂O₅N₁) was decreased in T0, whereas it was increased in T2 (Table 5) (Fig. 4).

This is the first study describing the effects of IPL treatment on the lipidomics analysis of the meibum after treatment with IPL in MGD. Based on the changes induced by IPL treatment, such changes are associated with reversal of different symptoms characteristic of meibomian gland disease. This treatment led to improvement of the ocular surface health resulting from increasing tear production, stabilizing the tear film, improving corneal epithelial cell contacts, and decreasing the conjunctival inflammation. Interestingly, IPL treatment also improved the quality and expressibility of the meibum from the meibomian glands. Therefore, IPL treatment provides a novel approach that may improve management of meibomian gland diseases in a clinical setting. IPL can be used as a predictive, preventive and presonalised medical scheme for the treatment of MGD patients.

IPL is a popular procedure for treating skin and ocular diseases. The IPL devices employ xenon gas-filled flash lamps to produce non-laser high-intensity pulses of polychromatic non-coherent lights in a broad-wavelength spectrum, from visible (515 nm) to infrared (1,200 nm). The mechanism of action of IPL systems is based on the principle of selective thermolysis, according to which certain targets, termed chromophores, are capable of absorbing and subsequently converting through non radiative transfer the impinging light into heat energy.

IPL treatment has been utilized for years in dermatological clinical practice^23,24. Recently, this procedure was also applied in ophthalmology to treat MGD^25,26,27. Its use for this purpose stemmed from declines in DE symptoms noted in patients who underwent IPL treatment for facial rosacea. Previous research studies confirmed the efficacy of IPL treatment in relieving the symptoms and signs of MGD^26,27.

In our study, the patient IPL treatment resulted in marked increases in both the BUT and aBUT values. As previously reported, these rises occurred as a result of improved tear film stability and a reduction in the tear evaporation rate. These effects are in accord with our measurement of a significant increase in tear production. Furthermore, we found that the ocular surface health improved based on declines in bulbar redness and corneal fluorescein staining.

IPL treatment also reduced capillary formation on the ocular surface which is advantageous to the restoration of corneal surface health. In addition, it is known to inhibit the formation of brown spots, and sun damage (excluding skin cancer) on the face, neck, chest, arms, and hands²⁸. Another previous study showed that IPL improved the orifice abnormality in MG¹⁸. In our study, although the IPL improved the quality and expressibility of the meibum, this procedure did not improve the orifice abnormality in MG.

The meibum is rich in lipids²¹. We hypothesized that the recorded improvement in the quality and expressibility of the meibum was due to an alternation of the meibum lipidomic profile. Based on the effects of IPL treatment on the principal component analysis of MGD patients, this procedure reversed a number of changes in the lipidomic profile towards patterns characteristic of those seen in healthy subjects. The moderate declines induced by IPL treatment in the MGD symptomology were associated with reversal of the hyperlipidemia in 12 of the 27 classes of lipids. It is possible that the restoration of the normal healthy profiles in this group of lipids contributed to suppression of MGD symptomology¹⁸. Of note, IPL treatment did not alter any of the other 15 classes of lipids changed by MGD. Furthermore, two sub classes (PC and PE) were higher than those in the untreated MGD group. Collectively, these results indicate that IPL treatment cannot completely reverse MGD symptomology, which is in accord with the failure of this procedure to fully reverse all of the changes in the lipidomic profile induced by MGD.

Despite the reversal of the changes in an appreciable number of lipid classes by IPL treatment, there were an appreciable number of insensitive lipid classes that could underlie failure of the treatment to fully reverse all of the MGD symptomology. Nevertheless, we found that the increases in 13 subclasses of lipids and decrease in one subclass of lipids in MGD could be reversed by IPL. They were rich in OAHFA, LPC, TG, and Cer. These lipids may be suitable markers for monitoring responses to IPL treatment. BUT, CR and meibum quality are three clinical indices that were vindicated as being relevant markers to assess IPL treatment efficacy.

Lastly, we found that IPL treatment could reverse some of the MGD-induced hyperlipidemia. These changes alleviated some of the MGD symptomology through stabilizing the tear film and improving the ocular surface health. Therefore, IPL can be used as an effective regimen for predictive, preventive and personalised in the treatment of MGD.

Consent to participate: Informed consent was provided by all patients following explanation of the nature and possible consequences of the study.

Consent to publication: All the authors checked the final manuscript and agreed to publish it.

Availability of data and material: All the data involved in this article can be obtained with the consent of the corresponding author.

Code availability: Not applicable.

Authors' contributions: Conceptualization: Hui Zhao and Shang-Kun Ou; methodology: Li-Ying Tang, Yi Shao and Shi-Nan Wu; resources: Hui Zhao, Dong Xiao and Zhe Cheng; visualization: Shi-Nan Wu, Jie Peng and Hua-Ying Hu; supervision: Hui Zhao and Shang-Kun Ou; funding acquisition: Hui Zhao. All authors have read and agreed to the published version of the manuscript.

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Table 1. A working diagram of data processing

Table 2. Clinical parameters before and after treatment of IPL in MGD
Clinical assessment	Before treatment	After treatment	P Value
BUT (s)	3.90 ± 0.10	5.02 ± 0.10	****（t=7.90,df=380.00）
aBUT (s)	4.93 ± 0.12	5.36 ± 0.10	**（t=2.77,df=374.50）
TH	0.17 ± 0.00	0.18 ± 0.00	**(t=2.64, df=367.10)
CR	1.24 ± 0.04	0.59 ± 0.03	****(t=12.95, df=380.00)
FL	0.43 ± 0.05	0.20 ± 0.03	****(t=4.15, df=380.00)
Orifice abnormality	0.97 ± 0.05	0.93 ± 0.05	P=0.57 (t=0.56, df=380.00)
MG drop out	1.31 ± 0.05	1.31 ± 0.05	P>0.99 (t=0, df=380.00)
MGE	1.34 ± 0.06	0.94 ± 0.04	****(t=5.80, df=380.00)
Meibum quality	1.27 ± 0.05	0.86 ± 0.03	****（t=6.73, df=380.00）

Note: BUT, break-up time; aBUT, average break-up time; CR, redness of conjunctival (CR) inflammation; FL, corneal fluorescein staining; MGE, meibomian gland expressibility. ** P<0.01，****P<0.0001.

Table 3. Significant different subclasses of lipids of T0 verse control
LipidIon	Class	Calmz	IonFormula	RT-(min)	Fold Change	P-value	VIP
SM(d32:1)+HCOO	SM	719.53	C38 H76 O8 N2 P1	8.743304	105.5802817	0.03955	1.27158
OAHFA(18:1/34:1)-H	OAHFA	785.74	C52 H97 O4	20.93825	52.16343297	0.03692	2.29603
Co(Q10)+NH4	Co	880.72	C59 H94 O4 N1	17.96348	49.2154925	0.03669	1.0111
OAHFA(18:1/32:2)-H	OAHFA	755.69	C50 H91 O4	18.67636	36.6853155	0.0444	2.04926
OAHFA(18:1/32:1)-H	OAHFA	757.71	C50 H93 O4	19.74312	29.63556255	0.04736	3.88388
SM(d40:2)+H	SM	785.65	C45 H90 O6 N2 P1	12.00555	21.94609662	0.03554	1.3621
TG(26:0/16:0/18:1)+Na	TG	995.9	C63 H120 O6 Na1	24.44222	21.32021673	0.02028	1.07358
Cer(d18:1/16:0+O)+H	Cer	554.51	C34 H68 O4 N1	10.187	14.87557017	0.01568	2.56661
PC(35:2)+H	PC	772.59	C43 H83 O8 N1 P1	10.84815	13.45758007	0.01122	1.40963
PC(34:2)+H	PC	758.57	C42 H81 O8 N1 P1	10.35652	9.044793221	0.02042	1.48086
LPC(18:1)+H	LPC	522.36	C26 H53 O7 N1 P1	2.829591	8.862523744	0.03903	1.58635
LPE(18:1)-H	LPE	478.29	C23 H45 O7 N1 P1	2.971951	8.196791624	0.0116	1.41347
Cer(d16:1/18:0)+HCOO	Cer	582.51	C35 H68 O5 N1	11.30124	8.162108672	0.00901	2.41341
SM(d42:1)+H	SM	815.7	C47 H96 O6 N2 P1	14.09983	7.808909475	0.00453	1.11772
TG(16:0/18:2/18:3)+Na	TG	875.71	C55 H96 O6 Na1	18.71938	7.301180438	0.0205	1.9029
LPC(18:1)+HCOO	LPC	566.35	C27 H53 O9 N1 P1	2.824801	7.164012181	0.00877	2.12477
SM(d38:1)+H	SM	759.64	C43 H88 O6 N2 P1	12.02927	7.023899481	0.0079	1.35097
SM(d18:1/16:0)+HCOO	SM	747.57	C40 H80 O8 N2 P1	9.977419	7.005964358	0.02223	2.06393
TG(16:1/18:1/18:2)+NH4	TG	872.77	C55 H102 O6 N1	19.68893	6.980513631	0.03026	1.53642
PS(39:1)-H	PS	830.59	C45 H85 O10 N1 P1	11.36284	6.821055558	0.03541	3.19895
PS(37:1)-H	PS	802.56	C43 H81 O10 N1 P1	10.3793	6.474225864	0.02929	1.56783
TG(16:0/18:2/20:5)+H	TG	877.73	C57 H97 O6	19.659	5.818026726	0.00493	2.28256
TG(18:1/18:2/20:5)+H	TG	903.74	C59 H99 O6	19.71597	5.444758925	0.00554	1.3387
SM(d40:1)+H	SM	787.67	C45 H92 O6 N2 P1	13.02854	4.693025458	0.01777	1.03408
LPC(16:0)+HCOO	LPC	540.33	C25 H51 O9 N1 P1	2.693533	4.427438179	0.0351	3.57942
So(d18:1)+H	So	300.29	C18 H38 O2 N1	2.422211	4.382913682	0.00565	2.80761
So(d17:1)+H	So	286.27	C17 H36 O2 N1	2.460979	3.940410295	3.91E-10	2.02106
LPC(18:0)+HCOO	LPC	568.36	C27 H55 O9 N1 P1	3.790138	3.64099302	0.03905	1.49809
LSM(d20:0)+H	LSM	495.39	C25 H56 O5 N2 P1	2.831587	3.444914731	1.08E-05	2.89417
Cer(d17:0/2:0)+H	Cer	330.3	C19 H40 O3 N1	1.913699	3.248423375	2.35E-06	1.85695
LPC(18:2)+H	LPC	520.34	C26 H51 O7 N1 P1	2.251227	2.988598263	0.00086	1.55151
Cer(d33:0)+H	Cer	526.52	C33 H68 O3 N1	9.731674	2.798888595	3.79E-05	1.15626
Cer(d35:0)+H	Cer	554.55	C35 H72 O3 N1	11.36469	2.720535667	8.07E-06	1.35036
TG(16:1/18:1/22:5)+H	TG	905.76	C59 H101 O6	15.60611	2.331510136	0.02129	1.30254
So(d16:1)+H	So	272.26	C16 H34 O2 N1	2.666427	1.985533979	0.01196	1.60794
CerG1(d17:1/16:0+O)+H	CerG1	702.55	C39 H76 O9 N1	9.514269	1.909466251	0.00627	1.18483
WE(6:0/16:3)+NH4	WE	352.32	H42 C22 O2 N1	3.006577	1.575320698	0.03507	1.08855
DGMG(16:0)+HCOO	DGMG	699.38	C32 H59 O16	2.678107	0.468996555	0.00695	1.61873
DGMG(18:2)+HCOO	DGMG	723.38	C34 H59 O16	2.225866	0.416667634	0.02013	2.13519
MGMG(18:2)+HCOO	MGMG	561.33	C28 H49 O11	2.625824	0.274625199	0.0003	1.38641
Cer(d18:1/18:0)+HCOO	Cer	610.54	C37 H72 O5 N1	12.32153	0.144934423	0.0018	1.9301

Table 4. Significant different subclasses of lipids of T2 verse T0
LipidIon	Class	Calmz	IonFormula	RT-(min)	Fold Change	P-value	VIP
Cer(d18:1/18:0)+HCOO	Cer	610.5416	C37 H72 O5 N1	12.32153	15.03078	0.026831	3.35324
PE(16:0/18:1)-H	PE	716.5236	C39 H75 O8 N1 P1	11.40335	2.846096	0.021526	1.55677
SM(d36:1)+H	SM	731.6062	C41 H84 O6 N2 P1	11.06469	2.472157	0.033226	4.39805
Cer(d17:0/2:0)+H	Cer	330.3003	C19 H40 O3 N1	1.913699	0.628695	0.000317	1.16972
LPC(18:2)+HCOO	LPC	564.3307	C27 H51 O9 N1 P1	2.255877	0.61314	0.014431	1.04162
LPC(18:2)+H	LPC	520.3398	C26 H51 O7 N1 P1	2.251227	0.586953	0.005786	1.05027
LPC(18:0)+HCOO	LPC	568.362	C27 H55 O9 N1 P1	3.790138	0.494036	0.034213	1.26986
TG(18:1/18:2/20:5)+H	TG	903.7436	C59 H99 O6	19.71597	0.489044	0.006754	1.65819
TG(16:0/18:2/20:5)+H	TG	877.728	C57 H97 O6	19.659	0.470568	0.004624	1.1926
LPC(16:0)+HCOO	LPC	540.3307	C25 H51 O9 N1 P1	2.693533	0.418414	0.017479	3.33535
LPC(18:1)+H	LPC	522.3554	C26 H53 O7 N1 P1	2.829591	0.410042	0.03062	1.52317
TG(16:1/18:1/18:2)+NH4	TG	872.7702	C55 H102 O6 N1	19.68893	0.387629	0.013507	2.03988
LPC(18:1)+HCOO	LPC	566.3463	C27 H53 O9 N1 P1	2.824801	0.381895	0.003515	1.85389
TG(26:0/16:0/18:1)+Na	TG	995.8977	C63 H120 O6 Na1	24.44222	0.354542	0.018517	1.12173
TG(15:0/16:0/16:0)+NH4	TG	810.7545	C50 H100 O6 N1	21.12598	0.320491	0.027543	1.9067
TG(18:1/18:1/24:1)+NH4	TG	986.911	C63 H120 O6 N1	23.61661	0.259233	0.029449	1.11668
TG(26:0/16:1/18:1)+NH4	TG	988.9267	C63 H122 O6 N1	24.07609	0.244438	0.037562	1.01093
TG(25:0/16:1/18:1)+NH4	TG	974.911	C62 H120 O6 N1	23.85067	0.241359	0.035602	1.03776
TG(26:1/18:1/18:1)+NH4	TG	1014.942	C65 H124 O6 N1	24.10026	0.214039	0.027703	1.34062
OAHFA(18:1/32:2)-H	OAHFA	755.6923	C50 H91 O4	18.67636	0.150416	0.005079	2.50278
OAHFA(18:1/30:1)-H	OAHFA	729.6766	C48 H89 O4	18.52064	0.144494	0.007217	3.26419
OAHFA(18:1/34:1)-H	OAHFA	785.7392	C52 H97 O4	20.93825	0.144425	0.003703	2.80631
OAHFA(18:1/32:1)-H	OAHFA	757.7079	C50 H93 O4	19.74312	0.136615	0.004611	4.81245
TG(18:1/17:1/18:1)+NH4	TG	888.8015	C56 H106 O6 N1	21.16226	0.131759	0.016443	1.66444

Table 5. Significant different subclasses of lipids of T0 verse control and T2 verse T0
LipidIon	Class	Calmz	IonFormula	RT-(min)	Fold Change	P-value	VIP Fold Change		P-value	VIP
OAHFA(18:1/34:1)-H	OAHFA	785.7392	C52 H97 O4	20.93825	52.16343297	0.036918	2.29603	0.14442499	0.003703	2.80631
OAHFA(18:1/32:1)-H	OAHFA	757.7079	C50 H93 O4	19.74312	29.63556255	0.047356	3.88388	0.136615378	0.004611	4.81245
OAHFA(18:1/32:2)-H	OAHFA	755.6923	C50 H91 O4	18.67636	36.6853155	0.044402	2.04926	0.150416143	0.005079	2.50278
LPC(18:1)+H	LPC	522.3554	C26 H53 O7 N1 P1	2.829591	8.862523744	0.039032	1.58635	0.410042149	0.03062	1.52317
LPC(18:0)+HCOO	LPC	568.362	C27 H55 O9 N1 P1	3.790138	3.64099302	0.039047	1.49809	0.494036433	0.034213	1.26986
LPC(18:1)+HCOO	LPC	566.3463	C27 H53 O9 N1 P1	2.824801	7.164012181	0.008767	2.12477	0.381895001	0.003515	1.85389
LPC(16:0)+HCOO	LPC	540.3307	C25 H51 O9 N1 P1	2.693533	4.427438179	0.035098	3.57942	0.418414154	0.017479	3.33535
LPC(18:2)+H	LPC	520.3398	C26 H51 O7 N1 P1	2.251227	2.988598263	0.000856	1.55151	0.586953112	0.005786	1.05027
TG(26:0/16:0/18:1)+Na	TG	995.8977	C63 H120 O6 Na1	24.44222	21.32021673	0.020276	1.07358	0.354541857	0.018517	1.12173
TG(18:1/18:2/20:5)+H	TG	903.7436	C59 H99 O6	19.71597	5.444758925	0.005544	1.3387	0.489043562	0.006754	1.65819
TG(16:0/18:2/20:5)+H	TG	877.728	C57 H97 O6	19.659	5.818026726	0.004927	2.28256	0.470568415	0.004624	1.1926
TG(16:1/18:1/18:2)+NH4	TG	872.7702	C55 H102 O6 N1	19.68893	6.980513631	0.030259	1.53642	0.387629187	0.013507	2.03988
Cer(d17:0/2:0)+H	Cer	330.3003	C19 H40 O3 N1	1.913699	3.248423375	2.35E-06	1.85695	0.628695394	0.000317	1.16972
Cer(d18:1/18:0)+HCOO	Cer	610.5416	C37 H72 O5 N1	12.32153	0.144934423	0.001796	1.9301	15.03077997	0.026831	3.35324

Alternation of Lipidomic in the Meibomian Gland After Exposure to Intense Pulsed Light in Patients With Meibomian Gland Dysfunction and Suggestions for Applications of 3PM Medicine

Status:

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Abstract

Figures

Key Points

Introduction

Patients And Methods

Results

Discussion

Declarations

References

Tables

Status:

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