European Medical Laser Association - image004 2024

Isaac Kaplan invented the laser in medicine.

Isaac Kaplan
Isaac Kaplan

He was born in South Africa and moved to Israel.

They named the Medicine University of Tel Aviv after him.

Laser imaging and diagnosis

Lasers have a major role to play in the early detection of cancer as well as many other diseases. For example, in Tel Aviv, Katzir’s group is looking at infrared spectroscopy using IR lasers. This is interesting, according to Katzir, because cancer and healthy tissue may have different transmissions in the IR range. One promising application of the technique is to measure melanomas. With skin cancers, early detection is very important for the patients’ survival rates. Currently, melanoma detection is done by the eye, so relies on the skill of the physician.

Laser-based systems are also starting to replace the x-rays traditionally used in mammography. Using x-rays poses a challenge: high intensities are needed to be able to detect cancers well, but as the intensity of the x-ray is raised, so is the risk of the x-ray itself causing cancer. The alternative being studied is to use very fast laser pulses to image breasts as well as other parts of the body such as the brain.

OCT for eyes and beyond OCT for eyes and OCT for eyes and beyond

There is much enthusiasm about the potential of optical coherence tomography (OCT) in many areas of medicine. This imaging technique can give high-resolution (on the order of microns), cross-sectional, and three-dimensional images of biological tissue in real-time, using the coherence properties of laser light. OCT is already used in ophthalmology and can, for example, enable ophthalmologists to see a cross-section of the cornea to diagnose retinal disease and glaucoma. It is now beginning to be used in other
areas of medicine too.

OCT for eyes and beyond OCT for eyes and beyond

In vivo microscopy

Lasers also play a key role in many different types of microscopies. There have been many medical developments in this area and the aim is to be able to see what is going on inside the body without cutting the patient open.

One example of an emerging area in medical applications is scanning near-field optical microscopy, which can produce images with a resolution much greater than that obtained from standard optical microscopes. This technique is based on optical fibers that have been etched at their tips at a smaller scale than the wavelength of the laser. This enables sub-wavelength imaging and paves the way for imaging biological cells.

PDT and other treatments

Developments in optical fibers are helping extend the potential uses of medical lasers in other ways too. In addition to enabling imaging techniques within the body, these enable the energy of the laser to be transmitted to wherever it’s required. The same optical fiber used in diagnosis could also be used in treatment. Esterowitz of the NSF predicts an increasing use of fiber optics in medical applications.

The area of photomedicine, using light-sensitive chemicals that act with the body in particular ways, also enables lasers to be used in both diagnosis and treatment. In photodynamic therapy (PDT), for example, a laser and a photosensitive drug can restore vision for patients with the “wet” form of age-related macular degeneration (AMD), the leading cause of legal blindness in people over the age of 50. In oncology, some porphyrins will accumulate in cancers and fluoresce if illuminated with a particular wavelength of light to show where the cancer is. If these same compounds are then illuminated with a different wavelength they become toxic and kill the cancer cells.

What is PDT?

The photosensitizing drug makes cells more sensitive to light and is attracted to the cancer cells. It does not become active until it is exposed to a particular type of light, usually a high-intensity laser light of a very specific wavelength. The drug is activated when this light is directed at the area of cancer, usually using a flexible optical fiber or a special lamp. The energy in the light activates the drug, which destroys the cancer cells by combining with oxygen to form a short-lasting substance that is toxic to the cells. Some
healthy, normal cells in the body will also be affected by PDT, but these cells will usually heal after the treatment. The very nature of PDT means that other body tissue will remain sensitive to light for up to several weeks after treatment. Therefore the patient needs to avoid direct sunlight and bright indoor light for a period afterward; otherwise, the skin gets very sensitive and may become very red a

d sore if it is exposed to light during this time. PDT has been in development since the 1960s but is not particularly widely used in the UK except in dermatology. The principal reasons for this lack of acceptance are the high cost of the drugs and laser equipment. The recent development of PDT is Intralesional PDT or I-PDT.

I-PDT

Intralesional-PDT (I-PDT) is a recent development from INTERmedic targeted at dermatological conditions. I-PDT is a selective, minimally-invasive treatment using a photosensitive drug that is activated by being irradiated with laser light to selectively destroy pathogenic cells while preserving the healthy ones. It is used to treat lesions internally at the desired depth and has proven clinical efficacy, with more than 7 years of study with proven results in these applications:

● Basal cell carcinoma 95%
● Keloids 90%
● Hidradenitis suppurativa 70%I-PDT is also indicated for: ● Fistulas
● Myxoid cysts
● Warts
● Anal fistulas
● Other tumors (palliative)

Frontal & Diffuse delivery fibers

For large basal cell carcinomas, fistulas and hidradenitis suppurativa. Internal and poorly located lesions. Penetrates to the desired depth.

Percutaneous applicator

For basal cell carcinomas and keloids. Well-located lesions. For external lesions, the photosensitive gel penetrates to 1 cm.

Laser tweezers are an aid to biomedical researchers

Optical tweezers, cell sorters, and a host of other laser-based tools are used by biomedical researchers around the world. Laser tweezers promise better and faster cancer screening and have been used to trap everything from viruses, bacteria, small metal particles, and strands of DNA.

Optical tweezers use laser light to hold and rotate microscopic objects, similar to the way we use metal or plastic tweezers to pick up small and delicate objects. Individual molecules can be manipulated by attaching them to a micron-sized glass or polystyrene bead. When a laser beam hits the bead, its light bends and exerts a small force on the bead, pulling it directly into the center of the beam. This creates an “optical trap” that can hold the small particle at its center.

laser eye surgery