Prof. Dr. Dr. Ludwig M. Heindl is a world-renowned specialist in eyelid/orbita/lachrymal duct/tumor surgery and general ophthalmology, working at the Center for Ophthalmology at the University Hospital of Cologne. He is an expert in his field with an excellent reputation thanks to his extensive experience and exceptional commitment to patient care. Prof. Dr. Dr. Heindl is a professor of ophthalmology and is one of the most recognized experts in the field, both nationally and internationally. He is known for his innovative contribution to ophthalmic oncology and ophthalmoplastic surgery.
Professor Dr. Dr. Heindl specializes in eyelid surgery, lacrimal duct surgery and tumours of the eyelids and conjunctiva. He is a recognized expert in the field of lacrimal duct stenosis and has developed a laser-based, incision-free technology that is successful and scar-free. Through his pioneering work, he has been instrumental in the advancement of minimally invasive surgical techniques that significantly improve the patient experience. One example of his holistic approach is his interdisciplinary collaboration within the tumor board, where he develops individual treatment concepts for patients with eye tumors together with other specialists. This holistic care aims to ensure that patients receive optimal care not only surgically, but also through alternative therapies such as radiotherapy and drug treatments.
Last but not least, the close and long-term follow-up care at the Cologne Eye Clinic is an example of Prof. Dr. Dr. Heindl's commitment to always keeping the well-being of his patients in mind. With a deep understanding of the diseases of the eye and the optimal combination of theory and practice, Prof. Dr. Dr. Heindl is a great doctor who provides excellent and sustainable services to his patients. His goal is not only to fulfill the medical needs of patients, but to perceive and treat them as people with unique therapeutic needs. In this way, he ensures excellent care and helps to significantly improve the quality of life of his patients.
The editors of the Leading Medicine Guide were able to find out more about ocular prosthetics in an interview with Prof. Dr. Dr. Heindl.
Millions of people worldwide are affected by various eye diseases. They can vary greatly in nature and severity, from harmless visual impairments to serious conditions that can significantly affect vision and quality of life. The most common eye diseases include cataracts, glaucoma, macular degeneration and tumors, which not only affect the physical health of the eyes, but can also cause emotional and psychological stress. A particularly sensitive and often overlooked area in the treatment of eye diseases is ocular prosthetics. When parts of the eye or even the entire eye are lost due to injury, disease or surgery, this can lead to significant limitations in quality of life. In such cases, an ocular prosthesis can be an important solution that not only takes aesthetic aspects into account, but also offers functional and psychological benefits.
The loss of an eye can have various causes, both traumatic and medical.
“The loss of an eye is often caused by severe trauma due to accidents at home, at work or during sport. Another common cause of eye loss is large tumors that can no longer be irradiated and the eye has to be removed. In addition, certain diseases, such as chronic eye diseases or serious infections, can also lead to the loss of the eye. An eye infarction can also lead to the loss of the eye and is often associated with glaucoma. An eye infarction leads to vascular occlusion in the eye. As a result, new vessels form, which leads to an increase in eye pressure and ultimately to an infarction. It is therefore advisable to see an ophthalmologist every year from a certain age and have your intraocular pressure checked,” explains Prof. Dr. Dr. Heindl at the beginning of our conversation.
Systemic diseases such as diabetes can also play a role in some cases by causing damage to the eye structures. In addition, complications following surgical procedures, such as cataract surgery or retinal surgery, can lead to the eye having to be removed. In rare cases, postoperative infections or other unexpected reactions can lead to irreversible damage. In all these cases, the need for an ocular prosthesis becomes relevant if an eye has had to be removed.
Prof. Dr. Dr. Heindl comments: “As a doctor, you have to approach the patient with great care, caution and time. And you have to differentiate between different patient groups. Trauma patients or tumor patients, for example, have until recently been able to see with an eye that is no longer intact, so the loss of sight is a massive turning point in their lives. Other patients, on the other hand, have already undergone numerous eye operations and have a long history of suffering and feel that the removal of the eye is a relief. Many patients report that they should have sought removal earlier. In any case, the loss of an eye is a life-changing event - but the perspectives are very different."
There are three different surgical methods for the loss of an eye.
“There is evisceration, enucleation and exenteration. The three methods differ in the surgical procedure and the indication area. In evisceration, an incision is made at the junction of the cornea and the entire inside of the eye is removed - choroid, retina, vitreous body - and a seal is inserted into the eye shell and sutured like a baseball. This has the great advantage that the eye muscles do not have to be removed, but remain attached to the eye shell. The conjunctiva is sutured over this and the prosthesis is then placed on top, which is significantly more mobile thanks to this procedure. However, this method cannot be used in all cases. The method does not work for tumors in particular, as the tumors have often grown into the eye shell, or more precisely into the sclera. And in the case of malignant tumors, it is essential to achieve a complete R0 resection. Therefore, the second surgical method, enucleation, must be chosen for these special cases. This involves opening the conjunctiva and removing the entire eyeball, including the eye shell, by severing the outer eye muscles and the optic nerve. The seal is then placed in this cavity and the eye muscles are sutured over it. With this procedure, the motility of the prosthesis is slightly worse than with evisceration. The third procedure is exenteration, which is used for a tumor that is so large that it grows into the eye socket. In this case, the eye socket must be removed down to the bone. Instead of a prosthesis, an epithesis is used, which only reconstructs the appearance of the eye. If the eye has been affected by a traumatic event, evisceration may be preferred. In principle, the procedures must be discussed individually with the patient. Only the generally preferred evisceration involves the risk of sympathetic ophthalmia, an inflammation against proteins of the other healthy eye,” explains Prof. Dr. Dr. Heindl about the surgical methods.
An epithesis for exenteration of the eye socket is an artificial eye prosthesis. It is used to reconstruct the cosmetic appearance of the face by replacing the lost eye. The epithesis is custom-made to resemble the appearance of the natural eye as closely as possible and is usually made of materials such as silicone or acrylic. It helps to improve the external appearance.
In ocular prosthetics, glass prostheses offer a number of advantages in terms of both the esthetic and functional aspects of ocular prostheses.
“In Germany, the prosthesis that is placed on the conjunctival stump is usually made of glass. This glass, a so-called cryolite glass, is specially manufactured in Germany, is characterized by its exceptional hardness, chemical resistance and smooth surface and is individually adapted. Due to the events during and after the Second World War, the supply of glass from Germany was discontinued. The other countries therefore had to replace the glass and the plastic PMMA (polymethyl methacrylate) was developed. As a result of this development, German-speaking countries still primarily use glass, while the rest of the world uses plastic. A number of studies have been carried out to compare the quality, which have shown that glass is clearly superior to plastic as a material, so that science also recommends glass. Glass is also much better in terms of aesthetics, as the reflection of glass comes closest to that of the human cornea. Glass is also better tolerated than plastic, which significantly minimizes the risk of inflammation and patients experience less discomfort overall,” says Prof. Dr. Dr. Heindl on the high quality of glass eyes and adds:
“The glass prosthesis should be replaced once a year because the surface becomes rougher due to the flow of tears. The plastic prosthesis, on the other hand, has to be ground down after one year, and the patient keeps their plastic prosthesis for around four to five years. Plastic also has its value - glass can break if the prosthesis falls off during cleaning, for example, but this is extremely rare. If the patient is involved in contact sports, then I would recommend plastic. However, glass is clearly the superior material."
The fitting process for an ocular prosthesis is a careful and multi-stage procedure aimed at ensuring an optimal fit and a natural appearance.
This process usually begins with an initial consultation, during which the patient is informed about their individual needs, expectations and wishes. Medical aspects, such as the cause of the eye loss and the patient's general health, are also discussed.
“It is trained prosthesis makers who make the prostheses - the training of these so-called ocularists takes five to seven years before they can fit ocular prostheses. To make an ocular prosthesis, the eye socket has to be analyzed to find the appropriate prominences. The prosthesis is then made from semi-finished prostheses, the size of a ping-pong ball, and customized in size and shape for the patient so that it fits perfectly into the eye socket. Of course, the color of the other eye is also taken into account and selected accordingly,” explains Prof. Dr. Dr. Heindl.
As soon as the final prosthesis is completed, another fitting follows. In this step, the prosthesis is inserted into the eye socket and checked again for fit, comfort and aesthetics. The prosthesis should fit comfortably and not cause any irritation. Aftercare is also an important part of the fitting process. The patient is informed about how to properly care for and clean the prosthesis to maximize its lifespan and ensure hygiene. In addition, regular checks are carried out to ensure that the prosthesis continues to fit perfectly, as anatomical conditions can change over time. If necessary, adjustments or even replacement of the prosthesis are required to ensure continued good functionality and aesthetics.
“Initially, every patient is naturally afraid of the removal of the eye and the possible esthetic disfigurement associated with it. However, this fear eventually gives way to the fear of losing vision in the other eye. Aesthetics are therefore no longer the problem after the operation, but the concern about the other eye. And this is exactly where you have to catch the patient,” says Prof. Dr. Dr. Heindl. Of course, there are also some risks. The eye specialist comments: “The eye socket can also scar, especially in younger patients. In addition, a lack of volume can occur because the eye socket collapses. In this case, fat must be transplanted. Then there is 'dry eye socket syndrome', a dry eye on the prosthesis side, which is why we very often give patients tear substitutes”.
The care and maintenance of a glass eye prosthesis is crucial to maximize its lifespan and minimize the risk of infection or other complications.
Regular and careful care not only ensures an aesthetically pleasing appearance of the prosthesis, but also contributes to the health of the surrounding tissue. “In the past, it was recommended that prostheses should only be worn during the day and taken out at night, which is now a no-go because the eye socket can then grow together. Today we know better. The ocular prosthesis should be worn at all times. Other recommendations also apply today with regard to regular cleaning. The prosthesis should remain in the eye socket for as long as possible, because if it is cleaned too often, healthy bacteria are also flushed out and this can change the microbiome of the eye socket. Some patients are completely satisfied if they wear the prosthesis continuously for six months, while others clean it once a week or once a month - this is very individual. In the USA, even longer wearing times are recommended, and I also advise my patients to leave the prosthesis in the eye for as long as possible,” advises Prof. Dr. Dr. Heindl and briefly explains how to clean it: ”To get the prosthesis out of the eye socket, there is a small suction cup that is placed on the prosthesis so that the patient can simply pull the prosthesis out. The eye socket is lined with conjunctiva - so the patient does not see an empty hole with the healthy eye. Nevertheless, patients are very anxious here and the whole process is to a certain extent an intimate act."
3D printing of ocular prostheses: Hype, challenges and the indispensable role of ocularists
“Two to three years ago, there was a real hype surrounding the generation of ocular prostheses from 3D printers. England in particular drove this development forward with a start-up company - a company that no longer exists. The core problem, however, is that although 3D printing for plastic prostheses is an interesting idea, customizing the eye socket is a particular challenge. The shape of the eye socket must be precisely captured. This is difficult as both the eyelids and the eye socket itself are movable. MRI or CT scans are of no help here, as they cannot fully depict the dynamic nature of the eye socket. Theoretically, a prosthesis could be produced using 3D printing, but the result would then have to be heavily adjusted and revised manually. This is precisely why the profession of ocularist is so important and irreplaceable. In Germany, there is the Professional Association of Ocularists, which is also involved in research projects on 3D printing of ocular prostheses. Research is in progress here, but at the moment I would advise any patient against having a prosthesis made using 3D printing,” says Prof. Dr. Dr. Heindl.
“Removing an eye is always an admission of failure per se. It is therefore important to develop new and even better therapeutic approaches to save patients from this painful step - the removal of an eye. As far as the manufacture of glass eyes is concerned, more development work should be done. Ocularists originally come from a craft background, but a study shows that integrated care could be the way forward. This care should consist of ocularists, ophthalmoplastic surgeons, psychologists and a specialized ophthalmologist who takes care of the remaining eye. There could also be changes to the material in the future. For example, the glass surface could be further optimized to improve its tolerance - an area that is also currently being researched,” says Prof. Dr. Dr. Heindl. That concludes our conversation.”
