Thermal pulsation treatment before cataract surgery improves symptoms of dry eye secondary to meibomian gland dysfunction: Study

Dry eye is a multifactorial condition characterized by inflammation of the ocular surface and tear film instability. Up to 86% of the patients with dry eye have an evaporative dry eye component type of dry eye primarily due to meibomian gland dysfunction (MGD). Inflammatory processes play a crucial role in the development and progression of dry eye. Cataract surgery also creates additional ocular inflammation during the post-operative period.

Measurement of tear cytokines can aid in identifying the specific inflammatory pathways involved in dry eye pathogenesis. Tear cytokine analysis can help evaluate the effectiveness of anti-inflammatory treatments in managing post-operative dry eye symptoms. Correlations between tear cytokine levels and clinical parameters, such as ocular surface disease index (OSDI) scores and tear film stability, can provide a comprehensive assessment of postoperative dry eye severity. Longitudinal monitoring of tear cytokine levels post-cataract surgery enables tracking of the inflammatory response over time and guides the optimization of treatment strategies.

Thermal pulsation is an FDA-approved therapeutic approach for MGD that combines controlled heat and pulsatile pressure to unclog blocked Meibomian glands. By restoring the normal function of these glands, Thermal pulsation aims to enhance tear film stability and alleviate dry eye symptoms associated with OSD. Thermal pulsation treatment has gained recognition as a non-invasive intervention to manage MGD and subsequent OSD symptoms.

The aim of the current study was to investigate the efficacy of Thermal pulsation treatment as a means of eliminating or significantly mitigating the exacerbating effects of cataract surgery on dry eye patients, by evaluating the comparative impact on post-operative signs, symptoms, and inflammatory cytokine levels within the tears.

This study was a Prospective, longitudinal, non-masked, randomized clinical investigation. The treatment group received Thermal pulsation therapy approximately 1 month prior to undergoing immediate sequential, same-day bilateral cataract surgery. The control group did not receive pre-operative Thermal pulsation but had cataract surgery performed in the same way, approximately 1 month after their baseline visit. Subjective questionnaires and objective clinical findings were evaluated at baseline, 1, 3, and 6 months after cataract surgery in the treatment group and control group.

A total of 62 patients were randomized into two groups of 31 representing 124 eyes. Subjective improvement was observed in the treatment group with OSDI and SPEED II scores. Mean (SD) of the OSDI improved significantly (p<0.01) from 56.98 (18.30) from visit 1 to 14.73 (12.22) at visit 4, and the mean (SD) of the SPEED II scores improved significantly (p=0.01) from 13.84 (6.12) during visit 1 to 7.1 (5.00) at visit 4 in the treatment group.

The purpose of this study was to compare the effects of Thermal pulsation on the signs and symptoms of dry eye patients following cataract surgery. Both groups received immediate-sequential, same-day, bilateral cataract surgery, with the same surgeon using injectable post-operative intracameral antibiotics and subconjunctival steroids. These unique study attributes combined to control for inflammatory differences between treatment and control groups secondary to surgery and/or postoperative care.

The treatment group received Thermal pulsation approximately one month prior to cataract surgery in this fashion, with the control group receiving Thermal pulsation treatment at the 3-month post-op visit. This time interval allowed for the examination of the effects of Thermal pulsation and artificial tears on signs and symptoms at 1-month post cataract surgery when the control group was still using artificial tears only.

At the 3-month time frame, the effects of Thermal pulsation on signs and symptoms were assessed in the treatment group compared to the control group.

Lastly, at the 6-month time frame, the effects of Thermal pulsation before and after cataract surgery were compared. The 3-month data from the treatment group and the 6-month data from the control group, which included the effects of Thermal pulsation after 3 months of treatment, were analyzed. Since most subjects had minimal use of artificial tears by the 6-month visit, any improvements in signs and symptoms were primarily attributed to the Thermal pulsation treatment.

The 2 key findings of this study were as follows:

1. Both groups demonstrated decreases in subjective symptoms following cataract surgery. However, one month post-operatively, the treatment group showed a statistically significant improvement in subjective symptoms across all three surveys (OSDI, SPEED II, and IDEEL) compared to the control group. The symptom difference between groups lost its significance at visits 3 and 4, although OSDI demonstrated a significant reduction again at the sixth-month follow-up visit despite the control group having received crossover therapy after visit 3.

2. There were no statistically significant differences between the treatment group and the control group for all objective signs measured across all visits, but some interesting trends were observed.

The findings of this study suggest that Thermal pulsation treatment leads to an improvement in symptoms of ocular surface disease, such as dryness, discomfort, and irritation. The positive outcomes in symptom relief following Thermal pulsation treatment align with previous research and support the effectiveness of this intervention in addressing patient-reported discomfort associated with ocular surface conditions. Patients experienced notable alleviation of dryness and improved overall comfort, which can greatly enhance their quality of life. However, no statistically significant improvements were observed in the objective signs of the disease, including tear film stability, ocular surface staining, and levels of inflammatory cytokines.

There were numerical improvements not reaching levels of significance in meibomian gland expression, meibum quality, NIKBUT, corneal staining, and multiple tear cytokines. Most of these effects were seen in the first three months after baseline and waned thereafter. Despite the lack of conclusive significant improvements in signs, the observed positive effects on symptoms highlight the potential of Thermal pulsation as a therapeutic option for patients suffering from ocular surface disease. Its pre-surgical use in patients prior to receiving cataract surgery provides some benefit within the first few months after surgery. Its impact thereafter appears to be less conclusive. Future research should aim to explore the long-term benefits of Thermal pulsation, as well as its effects on a broader range of clinical parameters and inflammatory markers.

Source: Vasudevan et al; Clinical Ophthalmology 2024:18 2239–2252