Technology reigns in oculoplastics, too

Some, like CT scans and MRIs, these surgeons have adopted. But then there is the Medpor Titan 3D orbital ...

By Charles Kim, MD, and Jacqueline Carrasco, MD, FACS

As in other ophthalmic specialties, technological advances have driven the evolution of oculoplastic surgery over the past few decades. While existing techniques continue to be refined, novel approaches and ideas are also improving the efficacy and efficiency of patient care. In addition, these evolving techniques and novel approaches have allowed the surgeon to keep up with the vast changes that have taken place within the health care system as a whole.

These countless advances have a wide reach, from the photographs taken during initial consultation to the instruments that allow surgeons to perform safe, reliable and efficient procedures.

In this piece, we will focus on a few broad categories where recent technology has made an impact on oculoplastic surgery, driving it forward.

Performing Thermage (Solta Medical), a noninvasive procedure that uses radio frequency energy to help tighten aging skin.

Photography

Besides their obvious importance for documentation, photographs are almost always required during the insurance authorization process. As such, cameras have become ubiquitous in the oculoplastics practice, with photographs taken both pre- and postoperatively, and often intraoperatively as well.

In our practice, we use compact point-and-shoot cameras due to their portability and ease of use. Compact cameras utilize a viewfinder, in which the displayed image passes through a lens that is distinct from the primary lens of the camera. In contrast, digital single-lens reflex cameras have only one lens, using a system of mirrors to transmit images to the viewfinder or the image sensor.

Given the voluminous number of images that accumulate quickly in a busy practice, a suitable computer is equally vital. It should have a large storage capacity, supplemented with a server that allows sharing of photos between multiple computers and safeguards against data loss in the event of computer malfunction.

Advanced image processing software is also necessary. We often refer to printouts of our patients’ external photographs intraoperatively, particularly during eyelid surgery. In addition, photographs of pertinent CT or MRI slices can be vital during orbital surgery. Processed images can focus the surgeon’s attention to specific areas of interest, and also compress the file size of the image itself to aid in storage. We use Adobe Photoshop in our practice for this purpose.

Diagnostic imaging

Oculoplastic surgeons use CT and MRI as their primary imaging modalities to evaluate patients with lacrimal, orbital and even eyelid pathology. Both CT and MRI scanning were introduced in the 1970s, although their use has become especially prevalent over the past two decades. Approximately 80 million CT scans were performed annually in recent years, while less than 4 million were obtained in 1980.¹

Imaging studies help the surgeon make accurate diagnoses, guide medical and surgical management of patients, and assess their response to treatment. Selecting the appropriate modality is dependent on both the nature and location of the disease process, and can be an art unto itself. In addition, many modifications can be made to the imaging modality of choice — such as fat suppression for MRI — that further enhance its overall clinical value in oculoplastic practice.

With CT scans, multiple combinations of X-rays produce cross-sectional images, which are generated based on the ability of tissues to absorb X-rays. CT scans can be obtained quickly and provide excellent visualization of bony structures, and are thus optimal for imaging patients with facial fractures, sinus pathology and thyroid eye disease.

Given its reliance on X-rays, however, there is an associated risk with cancer, and so careful consideration is required when ordering a CT scan on a pediatric patient.

In contrast, MRI avoids exposure to ionizing radiation and relies instead on a combination of magnetic fields, radio waves and field gradients to form images based on the different absorption and emission patterns within tissues. The generation of T1- and T2-weighted sequences further enhances the diagnostic utility of MRI. These sequences are produced by manipulating the repetition time (time between successive pulse sequences) and the time to echo (time between delivery of pulse and receipt of echo signal).

Endoscopy

Unlike the imaging techniques described above, endoscopes are inserted into the organ of interest, allowing direct visualization of the surgical plane. First described by Caldwell in 1893 and sparked by the advent of rigid endoscopes in the 1980s, endoscopic endonasal dacryocystorhinostomy (DCR) has emerged as a well-established method for the treatment of nasolacrimal duct obstruction.2 While endoscopic DCR has historically been associated with lower efficacy than the external approach, recent studies have demonstrated similar success rates.^2,3

In addition, endoscopic DCR offers surgeons and patients many other advantages, including the avoidance of cutaneous scarring, less intraoperative bleeding, a shorter postoperative recovery course and the ability to concurrently treat intranasal pathology.

Endoscopes have become increasingly popular among oculoplastic surgeons for both forehead rejuvenation (brow lifting) and dacryocystorhinostomy, as they minimize the use of incisions and damage to adjacent structures. The required components of endoscopy include an endoscope (rigid or flexible), a light source and a video unit. Rigid endoscopes are typically 4.5 mm in diameter, range from 18 to 23 cm in length and incorporate a 0- to 30-degree lens. A halogen or xenon light source provides illumination, and a coupling device equipped with the endoscopy system projects the images onto a video monitor.

For the purposes of brow lifting, endoscopy provides direct visualization of the supratrochlear nerve, which allows the surgeon to more safely address the medial brow approaches such as internal browpexy.

Lasers and non-invasive procedures

In clinical practice, lasers rely on the differential absorption by different structures within a given tissue — such as melanin and hemoglobin in skin — to achieve their effect. This allows for the targeted removal of lesions, resurfacing of skin, and creation of skin incisions. Oculoplastic surgeons use many types of lasers, including carbon dioxide, pulsed dye and neodymium-doped yttrium aluminum garnet, or Nd:YAG. However, carbon dioxide lasers can cause thermal damage to adjacent tissue and subsequent adverse effects on wound healing, which limit their use.

In contrast, nonablative lasers stimulate collagen production with heat while avoiding damage to overlying skin. This allows for faster recovery times and increased patient comfort, although multiple sessions are needed in most cases.

Similarly, both radiofrequency and ultrasound energy can generate the heat required to induce collagen formation — devices such as Thermage (Solta Medical) and Venus Freeze (Venus Concept) use the former, while Ultherapy (Merz) relies on the latter.

On the other side of the spectrum, cryolipolysis utilizes freezing temperatures to induce necrosis of subcutaneous adipose cells while leaving the overlying skin intact.

It is believed that the controlled cooling process induces a localized inflammatory response that ultimately leads to the fat reduction. Massachusetts General Hospital initially developed this technology in 2008, which is implemented in procedures such as CoolSculpting (Zeltiq).

Orbital implants

Over the years, alloplastic materials have become increasingly favored over autogenous bone grafts, which can have variable rates of resorption. Alloplastic implants consist of nonporous and porous varieties. Nonporous implants provide excellent structural support, but typically do not allow vascular ingrowth, leading to capsule formation at the graft-host interface. Examples include Teflon, nylon foil (SupraFOIL), silicone (Silastic) and titanium mesh.

In contrast, porous implants such as Medpor (porous high-density polyethylene) allow for vascular and osseous ingrowth, leading to even greater biocompatibility. The large pore size (100-200 μm) prevents capsule formation, maintains the host immune response, and minimizes infection. Medpor can also come embedded with titanium mesh, which imparts increased structural support and malleability, while providing better visualization on imaging studies.

The recently released Medpor Titan 3D orbital floor plate (Stryker) is a reformed implant designed from the accumulation of CT scan data to approximate the normal anatomy of the medial wall and floor of the orbit for use during fracture repair.

Conclusion

Technological advancements continue to push the field of oculoplastic surgery towards new heights, greatly enhancing the surgeon’s armamentarium in the evaluation and management of patients. We highlighted just a few of the areas that have been impacted by these innovations. New and emerging diagnostic and surgical techniques will undoubtedly pave the way for continued refinement and augmentation moving forward. OM

REFERENCES

About the Authors
	Dr. Kim is an oculoplastic surgeon in private practice in California. He completed his residency in ophthalmology at the New York-Presbyterian/Weill Cornell Medical College, followed by a fellowship in oculoplastic and reconstructive surgery at Wills Eye Hospital in Philadelphia, Pa.
	Dr. Carrasco specializes in eyelid reconstruction, thyroid eyelid/orbital surgery and cosmetic eyelid surgery. She serves as clinical associate professor of ophthalmology at Thomas Jefferson University in Philadelphia, Pa., associate surgeon at the Wills Eye Hospital and is an attending surgeon at Lankenau Medical Center. Additionally, Dr. Carrasco is a fellow of the American Society of Ophthalmic Plastic and Reconstructive Surgery and chairs the Wills Eye Hospital Cosmetic Conference. She is also the author of numerous articles on ophthalmology and oculoplastic surgery.