Meibomian gland dropout rate as a method to assess meibomian gland morphologic changes during use of preservative-containing or preservative-free topical prostaglandin analogues

Topical glaucoma medications - Possible implications on the meibomian glands

One of the most common causes of blindness on a global scale is glaucoma. There is a strong association between glaucoma and increased intraocular pressure (IOP). Because of this, adequate IOP-lowering is the most important treatment strategy, mostly through topical eyedrops. Well-functioning meibomian glands are paramount for maintaining a stable tear film, and their dysfunction is the most common cause of dry eye disease. There is a growing concern that both topical glaucoma medications themselves and their added preservatives damage the meibomian glands, and consequently, the ocular surface. Preserved topical glaucoma medications appear to cause dysfunction and atrophy of the meibomian glands. Upon comparison, preserved formulations caused more symptoms of dry eye, tear film instability, inflammatory changes and meibomian gland dropout than the preservative-free counterpart. However, although seemingly less detrimental, unpreserved alternatives may diminish glandular efficacy, and, depending on the active ingredient, lead to glandular death. This negatively impacts quality of life, adherence to treatment regimens and prognosis. In this review, we explore the available evidence regarding the effects of IOP-lowering eye drops on the meibomian glands.

Ocular Surface Disease in Glaucoma Patients

PURPOSE

To review the most recent studies in the literature regarding the ocular surface in glaucoma patients and treatment options aimed to reduce ocular surface disease in this population.

METHODS

We performed a literature search in the electronic databases of PubMed CENT RAL, Google Scholar, EMBASE the Register of Controlled Trials, and Ovid MEDLINE using the following terms: "ocular surface", "dry eye", "glaucoma", "selective laser trabeculoplasty", "glaucoma surgery", "preservatives", "preservative free", "ocular surface disease index", "tear break up time", "MMP-9" and "conjunctival hyperemia".

RESULTS

Over the last several years, several studies have demonstrated the changes to the ocular surface in the setting of glaucoma, the best tests for markers of dry eye, and how management can be altered to help address ocular surface disease routinely or in preparation for glaucoma surgery.

CONCLUSION

Ocular surface disease in the glaucoma patient population is widely recognized. It should be addressed to maximize patient compliance and quality of life.

Meibomian gland dysfunction patients benefit in ocular parameters and tear chemokines after thermal pulsation treatment

Objectives: To investigate the effect of thermal pulsation treatment on meibomian gland function, ocular parameters and tear inflammatory cytokines compared with the warm compress group. Methods: Twenty-five participants with MGD underwent a 12-minute thermal pulsation treatment, while 25 participants with MGD underwent manual warm compress treatment. MGD related parameters, including meibomian gland function (MGE, MQ and lid margin), tear stability (NIKBUT, FBUT and LLT), tear secretion (SIT, and TMH), were examined and OSDI questionnaire was also obtained. Tear chemokines (MIG, IFN-γ, IL-8, IP-10 and MCP-1) were examined and analyzed the correlations with MGD related parameters and OSDI. Results: Compared with warm compress subjects, OSDI, lid margin and tear stability were found improved more in thermal pulsation treatment at 3 months (OSDI: *p = 0.014, lid margin: *p = 0.021, LLT: **p = 0.008, CFS: *p = 0.028). The level of IP-10 and MIG decreased more in thermal pulsation group than in warm compress group (IP-10: *p = 0.021, MIG: *p = 0.039). IP-10 was positively correlated with MQ (r = 0.522, *p = 0.037) and negatively correlated with tear stability (r = -0.613, **p = 0.002), and OSDI was only positively correlated with IL-8 (r = 0.679, ***p < 0.001). The decrease of MIG was positively correlated with less corneal epithelium injury (r = 0.557, **p = 0.006) and meibograde (r = 0.49, *p = 0.019). Conclusions: Thermal pulsation treatment obviously improved MGD probably by attenuating tear CXCL chemokines in ocular surface of MGD patients, which demonstrated an efficacy and well-tolerated therapy in clinical.

Analysis of Cytokine Levels in Meibum and Clinical Correlations with Meibomian Gland Dysfunction

Objectives. This study is aimed at investigating the difference of meibum chemokines in MGD subjects with different degrees of MGD and the correlations of meibum chemokines with ocular surface parameters. Methods. Twenty MGD subjects (MQ $\text{score}>8$ ) and twenty MGD subjects (MQ $\text{score}\le 8$ ) were enrolled to examine ocular surface parameters, including meibomian gland function (MGE, MQ meibograde, and lid margin), tear stability (NIKBUT, FBUT, and LLT), tear secretion (SIT and TMH), OSDI questionnaire, and CFS. These subjects also obtained meibum samples, and then meibum chemokines (MIG, IFN-γ, IL-8, IP-10, and MCP-1) were examined and analyzed the correlations with ocular surface parameters. Results. MIG, IP-10, and MCP-1 were found clearly elevated in MGD subjects with higher MQ score than that in MGD subjects with low MQ score (MIG: $p=0.038$ , IP-10: $p=0.019$ , MCP-1: $p=0.040$ ). The meibomian function was found mostly positively correlated with level of MIG (MGE: $r=0.600$ , $p<0.001$ ; MQ: $r=0.579$ , $p<0.001$ ) and IP-10 (MGE: $r=0.719$ , $p<0.001$ ; MQ: $r=0.601$ , $p<0.001$ ). The tear stability was found negatively correlated with the level of MIG (NIKBUT: $r=-0.438$ , $p=0.005$ ; LLT: $r=-0.464$ , $p=0.003$ ) and MCP-1 (NIKBUT: $r=-0.425$ , $p=0.006$ ; LLT: $r=-0.761$ , $p<0.001$ ). The OSDI was positively correlated with IL-8, IFN-γ, and MIG. Conclusion. Chemokines in meibum were significantly evaluated in MGD subjects suffering from severe meibomian gland quality. These findings indicate that chemokines play roles in the pathogenesis of MGD, and molecules targeted by chemokines may develop as novel agents for MGD therapy, perhaps through inhibiting inflammation in meibomian glands and microvascular in the eyelid margin.

Hypochlorous Acid Can Be the Novel Option for the Meibomian Gland Dysfunction Dry Eye through Ultrasonic Atomization

Background

Dry eye is a multifactor disease which needs comprehensive treatments to keep the homeostasis of ocular surface.

Objective

To explore the effect of hypochlorous acid on the meibomian gland dysfunction dry eye through ultrasonic atomization.

Methods

We set this study of 0.01% HOCL and 0.1% hyaluronate by ultrasonic atomization. All the data was recorded at the 1^st, 15^th, 30^th, and 55^th days. The patients' complains, the meibum analysis, conjunctive congestion, corneal staining, Schirmer's I test, and NIBUT were recorded by K5M, the MMP-9, and IL-2 of tear by inflammation kit; the Demodex was recorded by microscopy.

Results

53 patients have joined this study. There is no statistic difference between them on OSDI (day 15: p = 0.061, 30: p = 0.055, 55: p = 0.052); results show the 10.57 ± 0.13 and 12.54 ± 0.17 reduction on OSDI; the differences of both treatments are significant (^∗∗p < 0.01). Increased Schirmer's and TBUT are 3.27 ± 0.10 and 6.29 ± 0.10 (^∗∗p < 0.01) or 7.32 ± 1.72 s and 9.22 ± 1.41 s (^∗p < 0.05); the decreased conjunctive and corneal staining are 0.23 ± 0.07 and 0.45 ± 0.06 (^∗∗p < 0.01) or 0.42 ± 0.03 and 0.37 ± 0.02 (^∗p < 0.05) at both groups. The differences of MMP-9 and IL-2 negative rate are significant (Z = 0.896, ^∗∗p = 0.002 < 0.01; Z = 0.659, ^∗∗p = 0.001 < 0.01); the number of Demodex mites at first is 10 or 11, while the last is 2 or 6 (Z = −4.642, ^∗∗p < 0.01; Z = 2.742, p > 0.05). The Demodex count between them is significant (Z = −2.310, ^∗p = 0.032 < 0.05). The survival times (ST) of each stage at the HOCL are 110.75 (108.50 ± 24.50), 95.50 (90.25 ± 14.50), and 75.25 (73.48 ± 8.50) min which are shorter than those of control which are 155.50 (160.10 ± 21.50), 130.25 (128.25 ± 16.50), and 105.75 (102.50 ± 14.50) min (^∗∗p < 0.01). The Demodex eradication rate of HOCL is statistic significant (^∗p15^th vs. 1^stday = 0.028 < 0.05; ^∗∗p30^th vs. 1^stday = 0.002 < 0.01; ^∗∗p55^th vs. 1^stday = 0.0018 < 0.01).

Conclusions

0.01% HOCL improves the Demodex eradication by shortening the survival time; the HOCL acts on the ocular surface by reducing the inflammation. The ultrasonic atomization helps for the drug usage.

Effect of Repeated Topical Povidone-Iodine and Antibiotic Applications on Meibomian Glands and Ocular Surface Parameters in Patients With Repeated Intravitreal Injections

OBJECTIVES

To assess whether meibomian glands and ocular surface parameters are affected by repeated topical povidone-iodine and antibiotic applications in patients with repeated intravitreal injections.

METHODS

Forty-five patients with at least three previous intravitreal injections and 28 healthy controls were included in the study. In the injection group, 21 patients had age-related macular degeneration and 24 patients had diabetic macular edema. For each participant, infrared meibography for the upper and lower eyelids and noninvasive tear break-up time calculation were performed with a corneal topographer. Fluorescein tear break-up time and ocular surface disease index (OSDI) scores were also obtained. Noninvasive tear break-up time, fluorescein tear break-up time, and OSDI scores were recorded for each participant and compared between the injection and control groups. These parameters were also compared as a subgroup analysis between patients with age-related macular degeneration (AMD) and diabetic macular edema (DME).

RESULTS

Upper lid meibomian gland loss, lower lid meibomian gland loss ratios, and OSDI scores were significantly higher in the intravitreal injection group compared with the control group (P=0.004, P<0.001, P<0.001, respectively). Fluorescein tear break-up time and noninvasive tear break-up time were significantly lower in the intravitreal injection group compared with the control group (P<0.001, P<0.001). There was no significant difference between the AMD and DME groups for these parameters.

CONCLUSION

This study showed for the first time that meibomian gland losses were significantly increased by repeated povidone-iodine and antibiotic applications in patients with repeated intravitreal injections. Ocular surface parameters were altered with higher ocular surface symptoms in those patients.

Comparison of the Intraocular Pressure-Lowering Effect and Safety of Preservative-Free And Preservative-Containing Brimonidine/Timolol Fixed-Combination Ophthalmic Solutions in Patients with Open-Angle Glaucoma

Purpose: To compare the therapeutic efficacy and safety of newly developed preservative-free (PF) brimonidine/timolol fixed-combination (BTFC) ophthalmic solutions and a preservative-containing (PC) BTFC ophthalmic solution in patients with open-angle glaucoma.Methods: This study was conducted as a multicenter, randomized, open-label, parallel-group clinical trial to evaluate the efficacy and safety of PF BTFC as compared with PC BTFC in adult patients (aged ≥ 19 years) with open-angle glaucoma (OAG) and ocular hypertension (OHT). A total of the 106 patients were enrolled, with 53 patients each randomized to the two treatment groups and included in the analysis of the safety set (SS).After a washout period, patients with an IOP below 35 mmHg at 9 a.m. were enrolled. After a full ophthalmic and glaucoma examination, a total of 106 OAG and OHT patients were randomized to the PF group or PC group.All subjects were examined 4 and 12 weeks after first administration. At each follow-up visit, IOP was measured at 9 a.m. and 11 a.m. and the efficacy, safety, and compliance were evaluated. Throughout the study, all adverse events were recorded and monitored by the investigators.Results The mean IOP changes from baseline to 12 weeks at 11:00 a.m. were -3.45 ± 2.53 mmHg in the PF group and -3.65 ± 2.76 mmHg in the PC group (p < .0001 for both). The difference in mean IOP change between the two groups was 0.20 ± 2.65 mmHg, which was not significantly different. The proportion of patients with IOP reductions of ≥ 15% and ≥ 20% and IOP at all-time points in the PF group were not significantly different when compared with in the PC group. There were no specific differences between the two groups regarding the incidence of adverse events.Conclusions PF BTFC ophthalmic solution shows a similar efficacy and safety profile to that of PC BTFC.

Changes in ocular surface and Meibomian gland after penetrating Keratoplasty

Background

To acquire desirable outcomes of penetrating keratoplasty (PKP), various factors affecting graft survival, visual function, and subjective symptom should be considered. As ocular surface and meibomian gland function are associated with these factors, this study aims to investigate changes of ocular surface and meibomian gland parameters after PKP.

Methods

This retrospective case series study included 24 eyes of 24 patients who underwent penetrating keratoplasty. Examinations on lipid layer thickness (LLT), meiboscore, tear meniscus area (TMA), tear breakup time (TBUT), corneal fluorescein staining (CFS), Schirmer I test (SIT), Ocular Surface Disease Index (OSDI), and meibomian gland functions were performed before and at 1 week, 1 month, 6 months, and 12 months after surgery.

Results

Compared to baseline (2.9 ± 0.6 s), TBUTs were longer at 1 week (4.4 ± 0.5 s, P = 0.027) and 6 months (4.4 ± 0.5, P = 0.048) after surgery. CFS values improved from baseline (6.5 ± 1.1) to 6 months (3.5 ± 0.6, P = 0.023) and 12 months (3.3 ± 0.7, P = 0.001) after surgery. Meibum quality value worsened at 1 week and 12 months after surgery and meibomian gland expressibility value worsened at 1 week and 6 months after surgery compared to baseline. OSDI scores improved at 6 and 12 months after surgery. Meiboscore showed no change throughout the follow up period. The patients with high preoperative meiboscore had worse meibomian gland expressibility at 6 and 12 months and meibum quality at 6 months postoperatively compared to their baseline and to those of patients with low preoperative meiboscore.

Conclusions

After penetrating keratoplasty, ocular surface parameters including corneal staining, TBUT, and OSDI significantly improved whereas meibomian gland parameters showed deteriorations, which was marked in patients with high preoperative meiboscore. Thus, perioperative management of MGD is recommended for patients who undergo penetrating keratoplasty, especially in patients with advanced MGD.

Topical preservative-free ophthalmic treatments: an unmet clinical need

Introduction: The main role of preservatives in eyedrops is to ensure sterility and microbiological integrity of the drug, and to facilitate the penetration of active compounds into the eye. However, several studies documented significant toxic effects induced by preservatives, especially on the ocular surface. Consequently, most of the ophthalmic medications became progressively available in preservative-free (PF) formulations.Areas covered: We analyzed pre-clinical and clinical studies on PF eyedrops with particular attention to common chronic diseases such as dry eye and glaucoma. We discussed about the pros and cons of using PF eyedrops, in terms of efficacy, safety, and social-economic aspects.Expert opinion: There are still unresolved issues that make hard for PF medications to definitively conquer the drug market. Despite robust pre-clinical evidences of less toxicity, the low number of randomized clinical trials does not permit to state that PF eyedrops have, in clinical practice, a similar efficacy or a higher safety compared to preserved forms. These aspects limit their use to chronic diseases requiring long-term therapies with multiple daily instillations, especially in the presence of concomitant ophthalmic diseases that expose to a risk of ocular surface worsening.

The protective effect of 3% diquafosol on meibomian gland morphology in glaucoma patients treated with prostaglandin analogs: a 12-month follow-up study

Background

To determine if 3% diquafosol (DQS) can preserve the meibomian gland morphology in glaucoma patients treated with prostaglandin analogs (PGA) for a 12-month follow-up period.

Methods

This study included 84 eyes of 46 normal tension glaucoma (NTG) patients who were treated with either preservative-containing PGA (PC-PGA; 16 patients, 28 eyes), preservative-free PGA (PF-PGA; 21 patients, 39 eyes), or a combination of PC-PGA and 3% DQS (PC-PGA + DQS; 9 patients, 17 eyes). The meibography of the upper eyelid was acquired using Keratograph® 5 M at baseline and at each follow-up (1, 3, 6, 9, and 12 months). Meibomian gland loss (MGL) was quantitatively analyzed by using ImageJ software.

Results

In the PC-PGA group, MGL increased significantly from baseline to month 9 and month 12, whereas no significant changes were observed in the PF-PGA and PC-PGA + DQS groups during the entire 12 months. All groups showed similar MGL at each follow-up time from baseline to six months. However, MGL in the PC-PGA group was significantly higher than those in the PF-PGA and PC-PGA + DQS groups at the 9 and 12 months.

Conclusions

Combining 3% DQS with PC-PGA was as effective as PF-PGA in preserving the meibomian gland morphology for at least 12 months. Our results suggest that 3% DQS may be a promising strategy for managing glaucoma patients with a high risk of developing meibomian gland dysfunction due to preservative-containing topical medications.