2005 Award Winners
Award-winning project: The Rostock Cornea Module RCM: Confocal laser scanning microscopy of the anterior segment of the eye
Project partners: Heidelberg Engineering GmbH | Steinbeis Transfer Center Biomedical Engineering and Applied Pharmacology in Ophthalmology/Rostock
At the Rostock Eye Clinic, a confocal laser scanning microscope was developed for imaging the microstructures of the anterior segment of the eye, including the lens, based on the Heidelberg Retina Tomograph HRT II. To this end, the Heidelberg Retina Tomograph HRT II was combined with a clip-on objective system, known as the Rostock Cornea Module (RCM).
If, in a laser-scanning ophthalmoscope, the refractive media of the eye – which form part of the laser’s focusing system in this device – are replaced by a high-quality objective system, the laser focus can be shifted to the anterior segment of the eye with a diameter of less than 1 µm. This results in a fast, high-resolution, digital confocal laser scanning microscope for in vivo examinations of the cornea. The successful implementation of the described concept of a microscope attachment system for a laser scanning microscope required the existence of a commercially available laser scanning system of a compact design. Following a comparison of several manufacturers, Heidelberg Engineering GmbH was selected as the project partner; the company is not only characterised by its great openness to innovative ideas but also, with the HRT II as the base unit for the laser microscope, has a global sales and training network at its disposal. Depending on the chosen objective combination and the internal z-scan, the 3D option allows a depth range of up to 50 µm within the specimen to be imaged with a depth resolution of 1 µm. The exposure time per image is 0.024 sec. This enables the documentation of dynamic processes in tissue (e.g. blood flow in vessels) as well as the capture of image sequences of 100 images in up to 10 seconds. This pressure-free corneal contact procedure is monitored by a small CCD colour camera. The contact method guarantees a fixed distance between the microscope and the cornea. This enables optical pachymetry. All microstructures of the cornea – including its epithelium, nerves and keratocytes – as well as the endothelium of the conjunctiva bulbi of the eye, and also those of the skin, tongue and oral mucosa, can thus be rapidly and reliably visualised and assessed. For the first time, it is also possible to visualise dendritic cells, known as Langerhans cells, in vivo.
The use of dry objectives in a non-contact procedure also allows, for the first time with this microscope, the imaging of the structures of the natural lens and secondary cataracts on an IOL. A key advantage of this instrument is its digital nature, which facilitates easy data archiving. The microscope has also been successfully used in other medical specialities, such as ENT and dentistry.