Gold PTT, also known as Gold Photothermal Therapy is an FDA-approved treatment for acne using selective photothermolysis. Although it was approved by FDA in 2018, it was offered by medical aesthetic clinics in Singapore just early this year.
Role of sebaceous glands in our skin
Sebaceous glands are tiny oil-producing glands present in the skin of mammals. They cover the entire body surface except the palms, soles and dorsum of the feet. They are the largest and most concentrated in the face and scalp. Sebaceous glands are usually attached to hair follicles in a pilosebaceous unit, consisting of an enlarged infundibulum, a multilobular sebaceous gland with multiple ducts converging into an opening onto the skin and a tiny hair – creating little openings on the skin, called pores.
When sebaceous glands are functioning normally, they produce and secrete sebum, which is a group of complex oils including triglycerides and products from fatty acid degradation, wax esters, squalene, cholesterol esters, and cholesterol. The purpose of sebum is to protect the skin against friction and damage caused by external factors. It also prevents your skin from drying out too quickly, keeping your skin and hair supple for a longer time.
Overactive sebaceous glands may cause acne vulgaris
While sebum is very important for skin health, overactive sebaceous glands can also cause acne. In order for acne to form, 2 things need to occur:
- Excessive production of sebum by the sebaceous glands
- Blockage of the hair follicles
The blockage of hair follicles is mainly caused by the skin not shedding its dead skin cells properly. The dead skin cells accumulate on the skin, clogging the pores. In addition, comedones, whiteheads and blackheads may also form on the pores. When the clogged pores get colonised by bacteria, skin inflammation occurs, and pimples develop.
It is these overactive sebaceous glands which the Gold PTT treatment targets.
The pathogenesis of acne is multifactorial and includes overactive sebaceous glands, follicular hyperkeratinisation, immunological changes, plugging of the infundibulum facilitating P.Acnes bacteria colonisation and inflammation of the skin.
How does Gold PTT treat acne vulgaris
To understand how Gold PTT works, we first need to understand what photothermal therapy is. Photothermal therapy is a type of light therapy which uses electromagnetic radiation, commonly in the near infrared (NIR) wavelengths in the form of lasers, for the treatment of various medical conditions including cancer.
PTT is similar to another older treatment for acne, known as photodynamic therapy, or PDT. However, the principle is different. Unlike PDT, PTT does not require oxygen to interact with the target cells or tissues. This means that PTT can penetrate deeper into the skin. Also, PTT causes less redness in the skin compared to PDT because longer wavelength lasers are usually gentler on the skin.
In this treatment, we combine the principles of PTT with gold nanoparticles. These specially designed nanoparticles are tiny – with a 120nm diameter silica core and 15nm thick gold shell.
When applied to the skin, the gold nano shells penetrate deeply into the follicles. When a laser is applied, the gold nanoshells localized into the follicles absorb the light and energy, get heated, and induce focal thermolysis of the sebaceous glands. Simply put, this action destroys part of the hyperactive glands.
Effects of Gold PTT and the treatment process
The goal of Gold PTT treatment is to reduce sebum production through selective photothermolysis. With less sebum produced, there is a cleansing effect in the sebaceous follicles. It is highly effective because we are targeting one of the root causes of acne directly. With reduced sebum, another beneficial side effect we often see is the reduction of pore size.
When we look at the skin under a microscope immediately post-treatment, localised thermal injury to the infundibulum in 84 percent of the subjects and 47 percent in injury to the sebaceous glands. The maximum depth of the thermal injury was 1.43mm, with an average depth of 0.47mm. More importantly, the adjacent dermis and the epidermis did not show signs of damage.
Acne treatment requires a holistic approach
Laser treatments are not the only way to treat acne. Acne, being a chronic condition, it is one of the most challenging conditions to treat. It often requires multiple modalities like topical creams, oral medication, facials and also lifestyle changes.
Recently with increased mask wearing, more people are complaining of breakouts. It is important to have a conversation with your doctor to understand the condition before undergoing a treatment program to combat this difficult skin problem.