Take a new look at existing devices, surgeon suggests

November 1, 2008

The high-tech devices available today are changing the way ophthalmology is practiced. According to the surgeon, the new technology found in state-of-the-art optical coherence tomography goes much further than assisting ophthalmologists in the diagnostics of anterior eye and retinal disorders.

Key Points

London-Advances in optical coherence tomography (OCT) devices, regardless of the manufacturer, are dramatically changing the ease and precision of ocular disease diagnosis and management in ophthalmology. The new technology that these devices wield can offer the clinician much more than what they originally were designed to do in the diagnostics of the anterior eye, lens, and retinal diseases, according to John Bolger, FRCS, surgeon, and founder and director of the Cataract Clinic, London.

A Fourier-domain OCT (RTVue-100, Optovue) is one device that uses this new technology, and it is designed to assist in the diagnosis and management of glaucoma, macular and sub-retinal hemorrhaging, and choroidal neovascularization.

"I just started to explore the device's potential in other areas, and I have been intrigued to find that it may open up other areas of interest which we have not delved into yet," Bolger said.

The papillary reaction so common in patients with allergic conjunctivitis can be imaged with the OCT, offering clarity of the cross-section of individual papillae in the conjunctiva. Bolger said that further adaptation of the technology possibly could offer conjunctival or lid histology imaging in the future.

"We may find that further enhancement of this device and its technology will give us a deeper detail within lesions on the skin or in the conjunctiva," he said. "Possibly, different wavelengths would be able to penetrate the tissues in and around the eye and give us different views of areas where we previously had to rely on conventional histology and post-mortem studies. Instead of doing a biopsy of a suspected lesion, we could actually just do an OCT, perhaps with the same machine or a new type of technology, to give us the histology we need."

Mechanics of the disease

Another area where the OCT can surpass its intended potential is its usefulness in clearly demonstrating to patients the mechanics of their disease such as their cataract or the narrowness of their angle in glaucoma, Bolger said. The sharp images from the OCT can assist patients in understanding the concepts more readily than a theoretic discussion about narrow angles, he said.

Typically, patients simply accept the gonioscopy results told to them by their ophthalmologist. With the help of the device, however, the patient is able to visualize the anatomical setup of his or her eye. He or she also is able to better understand the imminent risk of an acute angle-closure glaucoma and that an iridotomy may be required. Those symptom-free patients who have imminent pathology and yet are difficult to convince in regard to the gravity of their eye condition can be more easily swayed to undergo a certain intervention.

"A conventional examination may not give an eye surgeon the edge to demonstrate to the patient what the problem could be if action is not taken and, therefore, it is more difficult to convince the patient that intervention is appropriate," Bolger said. "Without this sort of input, it can be sometimes very challenging to convince the patient who is asymptomatic that something needs to be done."

Bolger recounted the case of a patient of his with juxtafoveal disease-a diabetic patient who was asymptomatic with just a couple of microaneurysms immediately adjacent to fixation. He said that the patient was unaware that there was any particular problem. Because Bolger was able to demonstrate to the patient the proximity of the microaneurysms to the line of vision on the device's screen, however, he ultimately was able to convince the patient that careful supervision was warranted.

In his experience, actively including patients in the management of their ocular disease therapy is extremely helpful because it saves a lot of valuable time. He said that instead of spending a lot of time explaining to patients a seemingly abstract concept, he now uses the OCT images to easily point out to the patient what their pathology is and what needs to be done about it.

New frontier

The advantages beyond what the device specifically is designed for are not exclusive to any one machine in particular, because devices such as the aforementioned Fourier-domain OCT device and a spectral-domain OCT device (Spectralis, Heidelberg Engineering) use very similar technologies. According to Bolger, the limits of this new technology still are unknown in terms of how it can revolutionize ophthalmology, and slowly, ophthalmologists will discover all the different ways the technology can be put to use in everyday practice.

He said that it is the task of ophthalmologists and users of these devices to go back to the manufacturers and inquire how the devices could be enhanced to be able to display different images of various structures, ultimately allowing ophthalmologists to perform different tasks concerning eye diseases.

"This is 'must-have' diagnostic technology, and the day of practicing ophthalmology with a slit-lamp and a Snellen chart are long gone," Bolger said. "Today's patient really deserves this level of diagnostics because it just improves everything-it makes it easier for the clinician to diagnose, it makes it easier for the patient to understand, and it facilitates the monitoring of treatments, whether retinal or glaucoma. Nowadays, one has to have this level of technology," he concluded.