Intense Pulse Laser Therapy and Dry Eye Disease

*Sana Niazi and Farideh Doroodgar*

### **Abstract**

The high and increasing prevalence of Dry Eye Disease (DED) highlights the need for new treatment treatments and more effective management strategies for this chronic disease. After training, lid grooming, and various ocular lubricants, the Tear Film & Ocular Surface Society Dry Eye Workshop II (TFOS DEWS II) Management and Therapy Subcommittee recently proposed Intense Pulsed Light (IPL) as the second phase of therapy. Brief flashes of non-coherent light (400–1,200 nm) are delivered to the skin's surface using IPL technology. Toyos et al. found in 2005 that rosacea sufferers who were treated with IPL in the periocular region had a significant increase in their dry eye symptoms.

**Keywords:** intense pulse laser, dry eye disease, meibomian gland, MGD

## **1. Introduction**

The lipid layer of the tear film is deficient when the activity of the meibomian glands is impaired, which protects the aqueous layer of the tear film and prevents it from evaporating. The cornea is exposed as the tear film is destabilized, which leads to the onset of DED symptoms [1]. Since facial rosacea is closely linked to Meibomian Gland Dysfunction (MGD) and blepharitis [1], the IPL intervention of rosacea may have removed pathological telangiectasia periocular area, eliminating a significant source of inflammation to the eyelids and, as a result, alleviating MGD and dry eye problems. Since Toyos' original publication, a slew of surveys and two Randomized Controlled Trials (RCT) [1, 2] have added to the body of evidence demonstrating the effectiveness (and safety) of IPL therapy for patients with DED caused by MGD [3]. Most of these studies showed that symptoms and a wide range of DED/MGD signals enhanced in these patients, such as Tear Breakup Time (TBUT), Non-Invasive Breakup Time (NIBUT), Schirmer examination, presence of phEx™. Tear inflammatory markers, lipid layer grade, lipid layer thickness, Corneal Fluorescein Staining (CFS), meibum consistency, meibum expressibility, and lid margin anomalies were investigated.

#### **2. Definition and history of DED**

Dry Eye Syndrome or Disease (DES or DED) is a chronic Ocular Surface Disease (OSD) that influences vision and, consequently, quality of life similar to angina pectoris.

The prevalence of DE varies by region and population, ranging from 5–50% and up to 75%. Female gender, Age, excessive cold or hot weather, low relative humidity,

#### **Figure 1.**

*Timeline diagram: IPL for DED treatment;* ↑*: Improvement, OSDI: Ocular surface disease index, BUT: Break up time, SPEED: Standard patient evaluation of eye dryness questionnaire.*

proximity to video monitor terminals, contact lens wear, history of refractive surgery, smoking, and prescriptions are some risk factors [4–13].

Geographical area, research demographic differences, and a lack of consistent diagnosis criteria are thought to cause the significant disparity of prevalence worldwide (**Figure 1**) [13].

#### **3. Diagnose of DED**

There is not a gold standard for diagnosing dry eye disease. However, evaluations can arise from the following methods:

#### **3.1 Standard patient evaluation of eye dryness (SPEED) questionnaire**

This validated questionnaire [1, 14] asked the subject to grade the frequency and severity of four symptoms categories: (1) dryness, grittiness, or scratchiness; (2) soreness or irritation; (3) burning or watering; and (4) eye fatigue. For each of these symptom categories, the subject subs-cored the frequency using a 4-point scale (0 = never, 1 = sometimes, 2 = often, 3 = constant), and sub-scored the severity using a 5-point scale (0 = none, 1 = tolerable, 2 = uncomfortable, 3 = bothersome, 4 = intolerable). The SPEED score was calculated as the sum of these eight sub-scores. A SPEED score ≥ of 10 is widely accepted as indicating severe DED symptoms, 12. A cut-off value around six is often used to distinguish between asymptomatic/mild and moderate/severe symptoms.

#### **3.2 Corneal fluorescein staining (CFS)**

Assessment of corneal staining was evaluated as follow: [15]. Immediately following TBUT measurement and taking advantage of the residual staining in the ocular surface, the examiner observed four anatomical quadrants of the cornea (temporal superior, temporal inferior, nasal superior, nasal inferior) under the slitlamp. Each quadrant was sub-scored using a 4-point scale; 0: no staining, 1: 1–30 instances of punctate staining, 2: 30 instances of punctate staining, without infused lesions or ulcers, or 3: the existence of infused lesions or ulcers. The sum of these

four sub-scores, ranging from 0 to 12, defined the CFS score. The CFS score was evaluated at baseline (BL) and follow-up (FU).
