Intense pulsed light (IPL) therapy targets pigment and has been used in dermatology for over two decades to help remove skin lesions, such as telangiectasia, hemangiomas, and acne rosacea. More recently, the application of IPL has expanded within the ophthalmic space due to unexpected findings. It has been noted that dermatology patients who experience meibomian gland dysfunction (MGD) improved both symptoms and overall dry eye disease (DED) with IPL treatments.1
IPL and dry eye disease
It is widely understood that inflammation plays a key role in initiating and perpetuating dry eye progression. In MGD, an inflammatory cycle is created, leading to the potential development of abnormal blood vessels known as telangiectasia. These abnormal blood vessels release pro-inflammatory mediators that further escalate inflammation.
Demodex mites and bacteria flourish in the inflamed tissue, which contributes to the clogging of the meibomian glands. As the lipid layer continues to fail, it sets off a chain reaction where both osmolarity and evaporation of the tears increases, leading to irritation and damage to the corneal surface.1
IPL treatments can offer long-term solutions for DED through various mechanisms of action and, more recently, have been cited in the Tear Film and Ocular Surface Society Dry Eye Workshop II (TFOS DEWS II) recommended staged management plan for DED, where it is labeled a second-stage management option.2
How does IPL work?
IPL is a non-laser high-intensity light source that uses a flash lamp to produce a light output of wavelengths in the range of 400 to 1200nm. It can deliver controlled pulses of intense red and infrared light with a duration of a few milliseconds, and this is applied to the eyelids and upper face.3
The multiple mechanisms of action for IPL may include:
1) Eliminating atypical blood vessels
When light passes through the filter and the desired wavelengths are produced, the incident light is selectively absorbed by the hemoglobin in telangiectatic blood vessels, causing the blood to coagulate and the vessels to involute and close. This destroys blood vessels that perpetuate inflammation and decreases the pro-inflammatory mediators contributing to MGD. Eliminating atypical blood vessels reduces a significant reservoir of inflammatory mediators, interrupts the vicious cycle of inflammation, and improves dry eye symptoms.3
2) Demodex infestation
IPL kills Demodex mites living in the vicinity of the meibomian glands. The chromophores in the exoskeleton of the mites absorb the IPL energy, eradicating the Demodex and the bacteria they hold, reducing the bacterial load on the eyelids. This helps reduce chronic inflammation, improving the fluidity of the secreted lipids and the quality of the lipid layer.3
3) Meibum secretion changes
In incidences of chronic inflammation, the meibum's composition changes to include more saturated fats. Saturated fats have a significantly higher melting point that is warmer than body temperature. This meibum then does not melt into the tear film's lipid layer as it should and clogs the glands. It is thought that IPL liquefies clogged meibum; however, it is uncertain if this is due to the thermal melting of the oil or a photochemical change to the oil’s structure.3
4) Lid function and aging
The light energy in IPL is absorbed by cytochrome C within the mitochondria, which is active in the electron transport chain (ETC) and improves adenosine triphosphate (ATP) production. This facilitates important cellular functions, such as collagen synthesis in fibroblasts and motility in immunoregulatory cells.
The ability of IPL to activate fibroblasts and enhance collagen synthesis at the eyelid skin level can help prevent the natural tendency of the skin to lose rigidity and elasticity with aging. IPL can help reduce poor apposition of the lid margins and incomplete blinks, resulting in increased meibum secretion and decreased tear evaporation.3
5) Meibomian gland structure
It has been shown that IPL can stimulate acinar cell activity, improving meibomian gland microstructure through the photomodulation effect. Photomodulation promotes cell activity like wound healing and photorejuvenation. NASA found that the optimal light wavelengths for photomodulation included 680nm, 730nm, and 880nm, which are all within the IPL wavelength spectrum used for treatment.4
The fundamental reason IPL successfully treats dry eye is that it addresses the upstream root causes of DED. Its multiple mechanisms of action collectively interrupt the vicious, inflammatory cycle that instigates and perpetuates dry eye.
What is involved in the IPL treatment process?
Patient selection is critical for safe, efficacious, and successful IPL treatments. It is indicated for those with MGD, with evidence of facial and/or lid rosacea.
Contraindications for IPL include:
- Skin tattoos within the vicinity of the areas of treatment.
- A recent history of high sun exposure or artificial tanning treatment.
- Unprotected sun exposure in the weeks before and following treatments.
- Systemic use of drugs causing photosensitivity.
- Systemic inflammatory connective tissue and skin diseases.
Prior to the IPL treatment
In general, IPL treatment areas include the skin overlying the cheeks and nose and, in some cases, the eyelids. This is mainly where the telangiectasia blood vessels reside and feed the inflammation in the eyelids. Patients should not wear face makeup for at least one day before treatment and should avoid products containing retinoids, as these products can cause increased sensitivity to sun exposure.
During the IPL treatment
Conventionally, treatment spans four to five sessions that are scheduled 2 to 4 weeks apart. Subsequent maintenance treatments normally consist of one treatment per year. After treatments, a moisturizer cream and sunscreen are advised as the skin can be sensitive for a few days.4
During IPL treatments, protection of the patient’s eyes is applied through an eye shield because melanin, along with hemoglobin, is also heated up by the IPL wavelengths. This means it is then possible for the iris to suffer thermal heat damage, which could result in intraocular inflammation and iris depigmentation.
“The eye shields also ensure that the eyelashes are not accidentally burned away.”
Treatment gel is applied to protect the skin from the heating effect and also to ensure that the light reaches the hemoglobin in the telangiectatic vessels without the need for excess pressure. Excess pressure would result in the flattening of the vessels, thereby occluding the blood flow and reducing hemoglobin exposure. It is also important that the gel is transparent because colored gel reduces light transmission.5
Patients should be warned that they may smell burning during the process. This is because the downy facial hair is burning, not the skin itself. Avoid the mustache and beard areas during IPL treatments, as the process may interfere with future facial hair growth.
Potential complications of IPL may include:
- Reddening of the skin
- Edema
- Burning sensation
- Temporary discoloration and bruising of the skin
- Skin hyper- or hypopigmentation
- Minimal pain
Using the Fitzpatrick Skin Type Scale
It is imperative that the pulse type, flash duration, and energy settings are tailored to the patient’s skin color. There are certain skin types that are more suited for IPL, and one way of evaluating this is through the Fitzpatrick Skin Type Scale (shown below). The scale provides a classification system of skin types based on the response to UV light. It categorizes skin types as a number between one and six, with a corresponding coloration of the skin and how it may react to sun exposure.6
The darker the patient’s skin color, the lower the treatment energy settings need to be. The energy settings can gradually increase as the inflammatory vessels recede with each subsequent treatment. The higher the energy, the more effective the impact on the meibomian glands, but also the greater chance of skin irritation.5
Figure 1 outlines the Fitzpatrick Skin Type Scale.
Figure 1: Image is taken from https://suttonderm.com/whats-your-type/
Available IPL instruments and systems
M22 Optima IPL
The M22 Optima IPL instrument from Lumenis ensures that light pulses are uniform and repeatable. The M22 uses a band wavelength filter set at 590nm and delivers controlled pulses of intense red and infrared light for a few milliseconds, which are applied to the eyelids and upper face. IPL treatment with the M22 is also used for a range of skin treatments. These include hair removal, acne treatment, freckle and age spot removal, and treatment of sun-damaged skin. The melanin in freckles and age spots is heated by infrared light and eventually fades with repeated treatments.
“Variable treatment depths can be achieved by selecting different wavelengths.”
The energy can also be lowered to treat fragile or sensitive skin and is compatible with a wide range of tip sizes that allow easy access around the tricky periocular anatomy. The M22 unit can also be fitted with additional software modules and attachments that allow for cosmetic treatments of deeper vascular lesions and pigmentation, resurfacing laser treatments for skin tightening, and wrinkle reduction.7
Figure 2 shows an M22 Optima IPL instrument on a stand.
Figure 2: Image is taken from https://lumenis.com/vision/products/dry-eye-and-optima-ipl/
OptiLight
The OptiLight features Lumenis’ FDA-approved IPL technology for improving signs of dry eye disease due to MGD. The optimal pulse technology and user-centered design allow for a consistent, precise, and controlled light-based treatment. OptiLight can help to address inflammation, restore meibomian gland structure and function, and reduce abnormal blood vessels, as shown by Lumenis’ IPL clinical trials and other studies.4,5,8,9
Figure 3 highlights an OptiLight instrument.
Figure 3: Image is taken from https://lumenis.com/vision/products/optilight/
Eye-Light
The Eye-Light from Topcon Healthcare offers IPL, as well as low-level light therapy (LLLT), which combines light modulation with optimized power energy (OPE). The unit treats inferior and superior eyelids simultaneously without needing a coupling gel. Instead, the Eye-Light has an internal cooling feature.
“The patient’s treatment parameters are managed by the unit’s software.”
The OPE uses a xenon flash tube to create a pulse with a 600nm wavelength and is applied to the periorbital area. The LLLT is delivered through a facemask containing an LED matrix designed to heat the upper and lower lids.7
Figure 4 features the Eye-Light instrument.
Figure 4: Image is taken from https://www.ophthalmicdata.com/wp-content/uploads/2019/09/EyeLightpdf.pdf
E>Eye
The E>Eye uses intense regulated pulsed light (IRPL) technology to treat DED caused by MGD. The pulses associated with IRPL technology are regulated and divided into sub-pulses, and each sub-pulse is separately managed with different durations and light intensities.
A polychromatic pulsed light produces perfectly-calibrated and homogeneously-sequenced “cold light” pulses which safely stimulate the meibomian glands to promote secretions.
This helps to restore the tear film and improve symptoms associated with ocular dryness. For optimal results, treatments are performed on day 1, day 15, day 45, and day 75, then as needed, according to the patient’s symptoms. Effectiveness lasts for 6 to 12 months after a full treatment. E>Eye units are small and portable, and treatments are quick, painless, and non-invasive.10
Figure 5 shows an E>Eye instrument.
Figure 5: Image is taken from https://imedpharma.com/irpl/
Comparing IRPL and IPL technology
A study completed in July 2020 by Yue Wu et al. compared the efficacy of IPL and IRPL therapy in patients with MGD. The results showed that both groups' clinical symptoms and signs were significantly improved at months 1 and 3 after IPL and IRPL treatments.
However, compared to the IRPL group, the IPL-treated group showed significant improvement in the clarity of meibomian gland secretions, the number of meibomian glands yielding clear liquid secretions, improvement in the first noninvasive keratograph tear break-up times (NIKBUT), and improvement in the fluorescein tear break-up times (FTBUT).
Overall, the study suggests that IPL has significant clinical value in treating patients with MGD, and that IPL treatment was potentially more effective in improving meibomian gland function in eyelids and tear film signs than IRPL treatments.11
Lumecca
Lumecca by Inmode claims that it is considered to be one of the most powerful IPL providers for the treatment of pigmented skin and vascular lesions currently on the market.9 Its technology allows for the effective treatment of light and darker skin types, and its range of treatments includes facial pigmentation, superficial vessels, skin texture, and photodamage.
“The device is meant to be used to achieve results in one to two sessions.”
To make treatments effective and precise, Lumecca uses a special handpiece that is equipped with a xenon flash lamp to treat the areas effectively and has a strong sapphire cooling tip that helps protect the surface of the skin to ensure maximum safety and comfort.12
Figure 6 shows the Lumecca instrument.
Figure 6: Image is taken from https://www.ginsbergeye.com/dry-eye-center-naples/ipl-therapy-for-dry-eye-lumecca/
Final thoughts
Overall, IPL has been shown to be a successful tool for managing dry eye because it treats several of the root causes of DED, including inflammation. There are multiple mechanisms of action through which IPL interrupts the inflammatory cycle that instigates and perpetuates dry eye.
It is an effective standalone procedure for patients suffering from evaporative, aqueous deficient, or mixed dry eye disease etiologies. Also, it can be added to pharmacological or other treatments in a multimodality approach to manage the multifactorial signs and symptoms associated with DED.
