The most common form of dry eye disease is evaporative disease.

The most common cause of evaporative dry eye is meibomian gland dysfunction (MGD). MGD may be triggered by skin disorders such as Acne Rosacea, blepharitis, microbial infection and ocular surgery. These increase the melting temperature of meibum, block gland openings and cause inflammation and atrophy of the meibomian glands. This causes tear film instability, exacerbating ocular surface disease.

Treatment methods include homeopathic treatments, topical and oral antibiotics, debridement, and application of heat to the glands. Homeopathic methods include supplementation of omega fatty acids, lid scrubs, and hot compresses. Topical azithromycin and oral doxycycline and azithromycin have been successful, but some patients prefer to avoid antibiotics. Debriding the lid margin, exfoliating using Blephex or heating the glands with compression also work well. They do not, however, address the underlying cause of the lid disease. A new procedure, Intense Pulsed Light (IPL) therapy, may.

IPL is typically used to treat acne rosacea by addressing the inflammation in the skin.

The IPL is based upon the principle of selective photothermolysis. Red blood cells contain the chromophore oxyhemoglobin, which has major absorption peaks at 418, 542, and 577nm. Optimal absorption is within the 577 to 600 nm range. Light energy absorbed by the chromophore is converted to thermal energy, which diffuses radially within the blood vessel leading to selective microvascular damage via photocoagulation and mechanical injury. If the pulse duration is more than the thermal relaxation time (TRT), tissue destruction and scarring are likely to occur.

Absorption of light is affected by several factors.

The depth of the vessel needs to be considered. The more superficial vessels respond to standard wavelengths (577, 585 nm), but deeper vessels require longer wavelengths (up to 600 nm). Thus, longer wavelengths allow deeper penetration and longer pulse width. Note that treatment should target the deepest part of the vessel rather than the most superficial. Larger diameter vessels require longer TRT and pulse duration. Vessel location is also important to consider. Although you may never treat them, vessels in the leg are deeper and contain more deoxyhemoglobin. These vessels prefer light in the 800-1200 nm wavelength. The anterior chest, neck, and periorbital area are more delicate, are prone to scarring and require a reduction influence of 10-20%. Fluence is the energy of laser light delivered per unit area. Younger patients have smaller and more superficial vessels and respond better to treatment. Because epidermal melanin absorbs the light energy, darker skin types require longer pulses, pulse intervals, and higher fluence.

Spot size is used to customize treatments.

Larger spot sizes have deeper penetration and shorter treatment time. Small spot sizes scatter the light energy more than larger size spots, which scatter less light and result in greater photocoagulation and swelling. Smaller spot sizes are recommended with manipulation of fluence to achieve the desired treatment level.

Purple and blue vessels tend to absorb more light energy than pink and red vessels and require less fluence. Smaller vessels absorb less light because there are fewer blood cells in the vessels, so these require more fluence to account for increased light scatter. Deeper vessel treatments benefit from cooling the epidermis to protect keratinocytes and melanocytes, although this is more common with lasers than IPL.
IPL produces a non-coherent light beam of 500 to 1200nm. Filters are used to narrow the output to 515, 550, 570, and 590 nm for vascular lesions. The filter settings enable a wide range of vascular/skin colors to be treated. Systems typically automate these selections to facilitate treatment.

In addition to targeting blood vessels in the lids and surrounding tissue, IPL appears to address other ocular surface disease issues. Heat transfer softens the meibum, facilitating expression of the glands. IPL has been reported to upregulate anti-inflammatory mediators such as interleukins, stimulate fibroblasts, and eradicate Demodex mites. It has also been reported to immediately reduce bacteria loads of the eyelid margin and surrounding adnexa, and the associated inflammation caused by them.

Studies

Craig et al evaluated the effect of intense pulsed light (IPL) applied to the periocular area for meibomian gland dysfunction (MGD) in a prospective, double-masked, placebo-controlled, paired-eye study. Twenty-eight participants underwent IPL treatment, with homogeneously sequenced light pulses delivered to one eye and placebo treatment to the control eye at 1, 15, and 45 days. Lipid layer grade improved significantly from day 0 to day 45 in the treated eye, but not the control eye. Impressively, 82% of treated eyes improved by at least one lipid layer grade. Noninvasive tear break-up time also improved significantly from day 0 to day 45 in the treated but not in the control eye. 86% of participants noted reduced symptoms in the treated eye by day 45.

Dell et al investigated the efficacy of  IPL, followed by meibomian gland expression for reducing the number and severity of signs and symptoms of dry eye disease secondary to meibomian gland dysfunction.3 80 eyes with moderate to severe MGD were treated. The following were measured were evaluated: tear breakup time, meibomian gland score, corneal fluorescein staining, Standard Patient Evaluation of Eye Dryness questionnaire, and tear film osmolarity. Enrolled patients underwent four treatment sessions, 3 weeks apart. Administration of 10-15 pulses of IPL on the cheeks and nose, with upper and lower eyelid gland expression, were completed at each session. After four treatments, TBUT significantly improved. SPEED improved by -55% (n=80; P<0.0001), MGS improved by -36% (n=80; P<0.0001), and CFS improved by -58% (n=38; P<0.0001). Lipid layer thickness did not change (n=38; P=0.88).

Vegunta, et al also retrospectively evaluated charts of 81 consecutive patients with dry eye treated using IPL and gland expression. SPEED2 significantly decreased after treatment. Meibomian gland expression improved in 37% bilaterally, and in 77% patients in at least one eye.

Gupta, et al retrospectively reviewed charts of 100 patients who underwent IPL with gland expression. Analysis of examination findings including eyelid and facial vascularity, eyelid margin edema, meibomian gland oil flow, and quality score (all graded on a scale of 0 to 4), tear break up time (TBUT), and ocular surface disease index (OSDI) was performed. Patients averaged 4 IPL sessions. A significant reduction in lid margin edema, facial telangiectasia, lid margin vascularity, meibum viscosity, and OSDI score. Significant increases in oil flow score and TBUT we also found. There were no cases of adverse ocular effects.
 Jiang et al prospectively evaluated forty eyes of 40 MGD patients who received 4 consecutive IPL treatments on day 1, day 15, day 45, and day 75. The following measures were used: best spectacle-corrected visual acuity, IOP, conjunctival injection, upper and lower tear meniscus height, TBUT, corneal staining, lid margin and meibomian gland assessments, and meibography. Significant improvements were observed in ocular surface symptom scores, TBUT, and conjunctival injection at all the visits after the initial IPL treatment (P < 0.05). Signs of eyelid margin disease, secretion quality, and expressibility were significantly improved at every visit after treatments. No complications were observed in any patient.

IPL therapy for evaporative DED appears to be a safe procedure which directly addresses MGD and the inflammation inherent to dry eye disease. Check with your state board to determine if you can offer this procedure to your patients.

[/restrict]


i Lemp MA, Crews LA, Bron AJ, Foulks GN, Sullivan BD. Distribution of Aqueous-deficient and Evaporative Dry Eye in a Clinic-Based Patient Cohort. Cornea. 2012;31(5):472-478.

ii Ding J, Sullivan DA. Aging and Dry Eye Disease. Exp Gerontol. 2012;47(7):483-490.

iii Dell SJ, Gaster RN, Barbarino SC, Cunningham DN. Prospective evaluation of the intense pulsed light and meibomian gland expression efficacy on relieving signs and symptoms of dry eye disease due to meibomian gland dysfunction. Clinical Opthalmology. 2017;11:817-827.

iv Kassir R1, Kolluru A, Kassir M. Intense pulsed light for the treatment of rosacea and telangiectasias. J Cosmet Laser Ther. 2011 Oct;13(5):216-22.

v Schroeter CA1, Haaf-von Below S, Neumann HA. Effective treatment of rosacea using intense pulsed light systems. Dermatol Surg. 2005 Oct;31(10):1285-9.

vi Toyos R, Fufu CM, Youngerman S. Case Report: Dry-eye symptoms improve with intense pulsed light treatment. Eye World News Magazine. 2005 September.

vii Byun JY, Choi HY, Myung KB, Choi YW. Expression of IL-10, TGF-B1 and TNF-α in cultured keratinocytes (HaCaT cells) after IPL treatment or ALA-IPL photodynamic treatment. Ann Dermantol. 2009;21(1):12-17.

viii Prieto VG, Sadick NS, Lloreta J, Nicholson J, Shea CR. Effects of intense pulsed light on sun-damanged human skin, routine, and ultra-structural analysis. Laser Surg Med. 2002;30(2):82-85.

ix Farrell HPP, Garvey M, Cormican M, et al. Investigation of critical inter-related factors affecting the efficact of pulsed light for inactivating clinically relevant bacterial pathogens. J Appl Microbiol 2010;108:1494-1508.

x Craig JP, Chen YH, Turnball PR. Prospective trial of intense pulsed light for the treatment of meibomian gland dysfunction. Invest Ophthalmol Vis Sci. 2015 Feb 12;56(3):1965-70.

xi Vegunta S, Patel D, Shen JF. Combination therapy of intense pulsed light therapy and meibomian gland expression (IPL/MGX) can improve dry eye symptoms and meibomian gland function in patients with refractory dry eye: A retrospective analysis.

xii Gupta PK, Vora GK, Matossian C, Kim M, Stinnett S. Outcomes of intense pulsed light therapy for treatment of evaporative dry eye disease. Can J Opthalmol. 2016 Aug;51(4):249-253.

xiii Jiang X1, Lv H, Song H, Zhang M, Liu Y, Hu X1, Li X, Wang W. Evaluation of Safety and Effectiveness of Intense Pulsed Light in the Treatment of Meibomian Gland Dysfunction. J Ophthalmol. 2016;2016:1910694.