The Bacteria Factor

Understanding and treating excessive bacteria colonization in patients with lid margin disease.

■ By Terrence P. O’Brien, MD

Bacteria have a causative or exacerbating role in many types of lid margin disease. In patients with blepharitis, colonization eventually can lead to infection. The microbe-mediated inflammation leads to some of the hallmark symptoms and signs, which can be quite severe.

Telltale signs include telangiectasias, marked erythema along the lid margin with meibomian gland dysfunction (MGD) or a conjunctival spillover with bulbar conjunctival hyperemia. Patients are often made miserable by the severe inflammation associated with blepharitis.

We now have a new prescription hygiene product that, in solution, offers excellent topical microbial spectrum coverage — Avenova, which contains Neutrox (pure hypochlorous acid 0.01%). To offer some perspective about how we can use Avenova in a lid hygiene regimen to help our patients, I would like to examine the role of bacteria in all types of lid margin disease and the importance of treating its excessive colonization.

Anterior and Posterior Disease

We can look at lid margin disease a number of different ways, but I think a clinically useful approach is to define lid margin disease based on the anatomy of the eyelid. Lid margin disease can exist in the anterior lid margin, where the cilia enter the skin, as well as in the posterior lid margin, where the meibomian gland orifices are located.

This anatomical distribution allows us to classify lid margin disease into anterior lid margin conditions, sometimes known as anterior blepharitis, and conditions of the posterior lid margin, known as MGD.

Anterior blepharitis is characterized by variably inflamed eyelids and accompanying lid margin telangiectasias. Patients also have scales and crusting, or collarettes, at the base of the lashes. With chronicity, patients can lose lashes (madarosis), have misdirected lashes (trichiasis) and may even experience scarring and notching of the eyelids.

Posterior blepharitis can be trickier to analyze because the symptoms aren’t always proportional to the signs. Some patients have severe symptoms with only minimal signs, while others have major clinical signs and only minor complaints.

» Figure 1. Skin flakes in the lid margin, combined with aqueous deficiency, make bacterial colonization a common factor in seborrheic blepharitis.

Signs of posterior blepharitis include meibomian gland pitting, capping, hypertrophy or inflammation. Posterior lid margin telangiectasias are common in posterior lid margin disease, especially with chronicity.

In cases of acute anterior blepharitis — flora, such as Staphylococcus — frequently colonize the anterior base of the lashes. It is less commonly known that flora are present in chronic posterior lid conditions as well. Organisms have been implicated in the pathophysiology of MGD, for example.

As we all know, anterior and posterior lid margin conditions often overlap. There is no fine line dividing the two lid margins, and many patients have mixed blepharitis with both anterior and posterior components. We will see more combination problems as our patient population ages.

Types of Anterior Blepharitis

Anterior blepharitis can be broken down into several categories. To treat anterior blepharitis effectively — and understand and address the inflammatory bacteria in each case — we must determine the underlying cause of the condition: Staphylococcus, dermatological disease or parasites.

Staphylococcal blepharitis: Staphylococcal blepharitis is one of the most common ocular conditions involving bacterial colonization. In fact, it has been estimated that 12% of eye care patients are seeking treatment for this condition.¹ We see it more commonly in patients 42 years of age and younger, and about 80% of cases affect female patients.²

Staphylococcal blepharitis causes inflammation with excessive colonization of the anterior eyelid margin.³ When I culture the lid margin, a high percentage of laboratory analyses report coagulase-negative Staphylococcus. We encounter Staphylococcus aureus less frequently, while some community patients carry methicillinresistant Staphylococcus aureus or other lid flora, such as corynebacterium or propionibacterium species.

Seborrheic blepharitis: We commonly see seborrheic blepharitis in older patients.^4,5 This type of blepharitis affects both sexes equally.

There is an obvious dermatologic association, and patients frequently have aqueous tear layer insufficiency. Clinical features include flaking skin in the lid margin. This debris in the lid margin, combined with dry eyes, make bacterial colonization a common factor.

Demodex blepharitis: The question of whether mites play a role in the pathophysiology of blepharitis has been debated for many years. Although this condition is uncommon, it remains an important part of a differential diagnosis for lid disease.

If parasites infest the lid margins and lashes, they leave debris and other material that can affect the pathophysiology of blepharitis and trigger inflammation. For some of these patients, especially those with cylindrical dandruff, there is an overload not only of parasites, but also of bacteria that play a role in their symptoms.

Controlling Lid Margin Bacteria

The primary reason to control lid margin bacteria for patients with blepharitis is simply to treat the condition. By reducing bacteria on the eyelids, we can reduce inflammation and bring symptoms under control. In addition, if a patient will undergo ocular surgery or intraocular injections, clearly we need to control excessive lid margin colonization in advance to prevent potential complications, including severe infections.

To address bacteria on the lid margins, I prefer pure hypochlorous acid (Neutrox, the active ingredient in Avenova by NovaBay). Avenova is the first daily prescription lid hygiene treatment. For the first time, we have a prescription weapon against lid margin disease that is effective, safe and unlikely to promote resistance. The product is also easy for patients to use. They simply spray a cotton round and clean their lids and lashes once in the morning and once at night.

Pure hypochlorous acid occurs naturally in the body. It is part of the body’s innate defense against invading pathogens. A potent killer of bacteria, hypochlorous acid also neutralizes many of the toxins that bacteria release, along with associated inflammatory mediators, to help suppress the body’s inflammatory response.

In the body, hypochlorous acid is released by polymorphonuclear neutrophils. To combat infection, a neutrophil tracks an invading microorganism, engulfs it, and releases hypochlorous acid as a potent killer.

How does this natural killer help us bring lid margin disease under control? If we look at the in vitro activity of pure hypochlorous acid, we find that it has excellent activity against a broad range of bacteria commonly isolated from the lid margins, eyelashes and ocular surface. Tested against 20 different organisms in solution, Neutrox reduced their numbers by 99.99% or more in 60 seconds.⁶

The data indicate that pure hypochlorous acid is indeed a broad-spectrum killer of microorganisms commonly found on the lid margins. Furthermore, it’s a natural product that’s well tolerated by patients. Thus, I think Avenova is an exciting advance that can be used to help our patients who are suffering from many types of lid margin disease, without contributing to the spread of antimicrobial resistance. ●

REFERENCES

CONCOMITANT PROBLEM: ROSACEA

When we see patients with lid margin disease, we often see overlapping dermatologic conditions, including ocular rosacea.

When a patient presents with common skin manifestations of rosacea, such as malar erythema, telangiectasias along the lid margins, rhinophyma and other features, we know that the ocular condition has an association with rosacea. We may have to co-manage the patient with a dermatologist to bring it under adequate control.

We also need to try to control the bacteria that is colonizing the lid margins because they impact the pathophysiology of ocular rosacea.

TERRENCE P. O’BRIEN, MD, is Professor of Ophthalmology and The Charlotte Breyer Rodgers Distinguished Chair at Bascom Palmer Eye Institute in Palm Beach Gardens, FL.

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