Adapting Your Practice to the Changing Landscape of Comprehensive Eye Care

Learn how spectral domain optical coherence tomography can help you deliver the highest level of care to your patients.

Rarely has delivering comprehensive eye care been as exciting — or challenging — as it is today. Innovative and novel new therapeutic agents, devices and procedures, as well as high-tech diagnostic equipment have created an environment of hope for patients with sight-threatening diseases. The challenge for eyecare professionals is to evaluate these new technologies and decide if and when it is appropriate to incorporate them into practice.

Advances in treating age-related macular degeneration (AMD), for example, have prompted changes to every aspect of patient care. AMD is now a treatable disease, whereas just 10 years ago, the best patients could hope for was that their disease would not progress quickly to blindness. Now, with the potential to save sight, primary eyecare practitioners must be vigilant about identifying and counseling patients who have risk factors for AMD, monitoring patients with dry AMD to detect progression, and referring patients to retina specialists for treatment when appropriate. In addition, because of the nature of AMD therapy, patients should be monitored during and after treatment to assess treatment efficacy and watch for a resumption of progression, which could signal the need for additional therapy.

How are primary eyecare providers dealing with the challenges presented by AMD and other retinal diseases? One tool that is becoming invaluable to many is optical coherence tomography (OCT). Here is how optometrists are using this technology to deliver the highest level of care to their patients.

Lifting Limitations

In the past, eyecare practitioners have been limited by the types of diagnostic instruments available. New technology is eliminating these impediments to fast, accurate and easily acquired data that are essential to diagnosis.

"Not long ago, visualizing the macula with a slit lamp and diagnostic lens, along with fundus photography, was the best way to diagnose AMD and to monitor the dry form of the disease," says Jeff D. Miller, OD, Cockrell Eyecare Center, Stillwater, Okla. "When I detected a change in a patient's vision or in the appearance of his macula, I would send him to a retina specialist for fluorescein angiography and a diagnosis. Unfortunately, because of our limited diagnostic tools, there was always the possibility that one of my patients would have 20/20 visual acuity at a routine visit, develop a problem between examinations and return too late to fully preserve his vision."

Today, the chance of such a scenario has been significantly reduced simply because of the improved images and metrics available with SD-OCT.

"We use the spectral domain Cirrus HD-OCT (Carl Zeiss Meditec). This technology has revolutionized our approach to retinal diseases, taking us from a fundus photograph or a slit-lamp view through a 90-diopter lens to a cube of data comprised of 128 scan lines, each providing 512 A-scans. With this technology, we can see areas that we have never seen before. We can look at crosssections of the retina with phenomenal detail, and macular thickness down to just a few microns."

Using the Cirrus HD-OCT

The Cirrus HD-OCT can image a 6mm cube of data in the macula or isolate specific areas of pathology. As Dr. Miller describes: "With the cube scan, I can look at every layer, go through it in a movie format and split out retinal layer maps, including the inner limiting membrane and the retinal pigment epithelium."

The 5-line Raster provides 5 scan lines of cross-section with 4000+ A-scans per line. The new Enhanced HD Raster scan provides even more highly detailed images. Each line of the 5-line raster is repeated four times and then, from the four lines, the best pixel at each data point is selected to construct an enhanced image. This process is called Selective Pixel Profiling™. An optional single line scanned 20 times is also available. "Instead of struggling to interpret photographs of an AMD suspect, I perform an OCT examination and usually can see the problem right away," Dr. Miller says.

According to Dr. Miller, using the Cirrus HD-OCT improves his ability to make timely referrals for a wide range of pathologies. "If a patient has diabetic cystoid macular edema (DCME), for example, I may see retinal thickening with a slit lamp view, but I can confirm DCME with the Cirrus HD-OCT," he says. "By recognizing that a case of diabetic retinopathy needs treatment earlier in the course of the disease, I can help patients avoid macular scarring and permanent vision loss, and hopefully prolong or avoid the onset of proliferative diabetic retinopathy."

Complex Testing Simplified

Spectral domain OCT is fast and easy to use, and it has powerful software to enable accurate image capture and interpretation of the vast amount of data it collects. According to Dr. Miller, this is in contrast to time domain OCT, which requires a more highly skilled technician with aboveaverage knowledge of how to capture a scan of retinal pathology.

"With the Cirrus HD-OCT, my technicians point and shoot over the macular area to acquire a cube of data," Dr. Miller says. "I evaluate the cube onscreen, moving my cursor through the B-scans to detect pathology. I am responsible for recognizing and diagnosing problems, so I am happy my technicians are capable of obtaining excellent scan results with minimal training."

The Cirrus HD-OCT software also includes a feature called the auto Fovea Finder™, which automatically detects the precise location of the patient's fovea, even if the patient has lost central fixation due to AMD or other pathologies. In addition, a change analysis feature uses a registration application that takes a data cube from the most recent examination and automatically registers it to an earlier examination, using landmarks in the OCT fundus image. It lines up the data exactly with previous scans to enable comparisons over time. The software also incorporates a valuable normative database.

"When I am drawing conclusions about images, I use the macular thickness normative database with color-coded ETDRS thickness grids, which allow me to evaluate retinal thicknesses that may be outside the norm," Dr. Miller explains. "The database provides age-matched comparisons to avoid misleading results. For example, if I am evaluating a 60-year-old patient, probability indices can tell me the likelihood that a 60-year-old in the normal population would have similar macular thickness measurements. When I am monitoring patients over time, the software also offers macular change analysis, which presents as ETDRS thickness grid overlays. Changes are highlighted and measured to within just a few microns.

According to Dr. Miller, spectral domain OCT enables him to detect problems earlier in the disease process, allowing for timely referral and treatment and potentially preventing disease progression and vision loss. "If we didn't have this instrument and instead used standard monitoring practices, we could detect wet AMD in a timeframe that was acceptable 5 years ago, but, in my opinion, that standard no longer applies," he says. "Today, patients with 20/20 or 20/25 vision [but who have AMD] can receive treatment before they are even aware they have a problem."

For some practitioners, incorporating OCT into practice has been transformative. For example, when Aaron Lech, OD, acquired ClearVue Eye Care in Roseville, Calif., the practice focused mainly on routine refractive eye care. In just a few years, he has added a focus on the management of eye disease. Optical coherence tomography is an integral part of that transformation.

Case Study: OCT Uncovers Post YAG Complication

A patient who was in for a 1 day post-op following YAG capsulotomy presented with visual acuity of 20/25. This patient had undergone multiple glaucoma surgeries over the years, as well as cataract surgeries, so I felt his visual acuity was good at 1 day post-op. The patient, however, felt the quality of his vision was "a little odd." Since the patient had pinpoint pupils, fundoscopy was difficult. Thinking the patient might have some sort of macular problem, I ordered an SD-OCT scan, which revealed a retinal detachment. The results were fast and I didn't have to dilate the patient. If I had not run the OCT, I would have sent this patient home with an appointment to see me again in 1 week, which is my standard protocol post-YAG surgery. But it might have been too late to preserve his vision. Instead, I immediately sent the patient to the retina specialist for a retinal detachment repair. Having the Cirrus HD-OCT and being able to use it quickly and easily — a staff member ran the scan, which I analyzed — saved this patient's sight. His vision after his retinal repair is 20/20-1. That really hits home for me. — Aaron Lech, OD

Case Study: OCT Reveals AMD During Routine Visit

An 84-year-old man came in for an annual eye examination with no significant complaints, but said: "I don't think I'm reading as well as I was right after cataract surgery, but I can't tell if it is one eye or both." His health history was remarkable for controlled hypertension and high cholesterol. The patient was 12 years post cataract extraction with IOL implants OU. His uncorrected vision was 20/40 OD and 20/50 OS. His best-corrected visual acuity was 20/30 OD and 20/20 OS. His anterior segment showed grade 2 posterior capsular fibrosis OD and grade 1 OS. His IOLs were wellpositioned, and his IOPs were 12 mmHg OU. The patient's maculas demonstrated retinal pigment epithelial (RPE) changes OD > OS consistent with mild atrophic AMD OD. His optic nerves showed clear margins and were nonglaucomatous OU. A Cirrus HD-OCT scan was obtained for baseline and demonstrated an RPE disturbance with suspect subretinal fluid OD. Based on the OCT findings, I referred this patient to a retina specialist. Subsequent fluorescein angiography demonstrated a subfoveal choroidal neovascular membrane (CNV) OD. The wet AMD was treated with a combination of photodynamic therapy with verteporfin (Visudyne, Novartis) and bevacizumab (Avastin, Genentech). The patient has since had two additional bevacizumab injections and his vision remains at 20/30 BCVA OD. Without OCT, the patient's fundus photograph alone would not have revealed the problem, and the patient would have been asked to return for follow-up in 6 to 12 months or immediately if home Amsler grid or vision changed. Under these circumstances, and considering the location of the CNV, this patient's prognosis would have been significantly different. In my opinion, Cirrus HD-OCT made all the difference in this case, because it helped preserve this patient's vision. — Jeff D. Miller, OD

Simple OCT Protocols

Dr. Lech began using time domain OCT about 4 years ago. This year, he added the spectral domain Cirrus HD-OCT to his practice, improving his ability to diagnose and monitor retinal pathologies and glaucoma. Dr. Lech has developed protocols for efficient use of OCT in his practice. For example, only patients who meet specific demographic criteria and who are at risk for certain diseases are screened. "I look at a patient's age, race, sex, family history and personal history, as well as lifestyle choices, such as tobacco use, to determine if he is at risk for certain diseases," Dr. Lech explains. He also screens patients known to have diabetes or other systemic conditions that have been linked to retinal pathologies.

"I use OCT on any and every patient who has a retinal pathology when I need more clinical or diagnostic data," Dr. Lech says. "I also use it for all of my glaucoma patients, regardless of where they are in the glaucoma continuum — from suspects to advanced disease. With this technology, I can compare the eyes side by side and evaluate symmetry. If a patient's visual fields are inconclusive but his optic nerve is suspicious, the objective data I obtain with the Cirrus HD-OCT helps me determine whether or not there is a problem."

Dr. Lech's screening protocol, for which patients pay a separate fee, includes an OCT scan, which gives him a quick "snapshot" of a patient's status. If this scan reveals something suspicious, he takes additional, detailed scans for a more comprehensive analysis. If he feels visual fields and/or fundus photos are warranted, he has the patient schedule a follow-up appointment for these tests. "Insurers require that there is a clear distinction between our screening protocol and our treatment and monitoring protocol," Dr. Lech explains. "With many insurance companies, OCT cannot be done on the same day as fundus photos and visual fields."

Dr. Lech cites ease of use — his staff can acquire a full set of scans in 5 minutes or less — and the fact that dilation seldom is required as key advantages of the Cirrus HD-OCT. "The clinical data provided by the Cirrus HD-OCT is very valuable," he says. "I can confirm or rule out conditions with an efficient use of time and resources."

According to these practitioners, OCT also can play a role in strengthening patient loyalty.

Patients' Perspectives

In today's competitive environment, it is important to build a reputation that inspires confidence and distinguishes your practice as one of the best. Comprehensive care and added services, such as spectral domain OCT, make a lasting impression on patients.

"When patients receive a level of care that exceeds their expectations, they are more likely to remain loyal to the practice," Dr. Miller says. "Say, for example, you found signs of disease and could show your patient detailed images of his eyes. Not only do you demonstrate your expertise as a diagnostician, but you also show that your practice is equipped with the latest technology. Older patients, in particular, feel more confident knowing their doctor is vigilant about monitoring age-related eye diseases. When patients are impressed and satisfied, they tell their family and friends about their experience."

Spectral domain OCT also serves as an effective patient education tool, enhancing a patient's understanding of his condition and demonstrating the importance of complying with therapy. In some cases, practitioners have been able to reassure patients that their conditions are improving by showing them their OCT scans.

"In the past, when I have had patients with central serous retinopathy, even though I told them they were improving and the condition would resolve, they still were anxious and needed reassurance," Dr. Lech says. "Using macular change analysis on subsequent visits, however, I can show them how their condition has improved over time, and they are reassured.

"When my patients look at results from this test, as opposed to any other test that we do, they can see what I'm telling them. The color coding and graphs tell the story more succinctly than I can. Patients look at their scans and say 'I get it. I see what you're telling me, and I'm really glad you ran this test.' Anything I can use to engage my patients and enhance compliance is beneficial."

According to Dr. Miller, another intangible but very real benefit of spectral domain OCT is its "wow" factor. "Patients feel like they are in a high-tech office, and that has a positive impact. They remember seeing the scan of their retina — something they know they can't see at every practice — and they tell their friends about their top-notch experience."

Timely, Seamless Eye Care

When eyecare professionals can make fast, accurate diagnoses, their decisions if and when to refer patients for specialized treatment are expedited, and patients are beneficiaries of timely and seamless eye care.

"Adopting technologies that will improve our ability to detect and monitor ocular diseases enables us to better serve all of our patients," Dr. Miller says. "Spectral domain OCT gives us more data, better data and the analysis capabilities we need to make decisions with confidence."

Timely Referrals The data generated by the Cirrus HD-OCT also have improved the timeliness of referrals, according to Dr. Miller. "Using spectral domain OCT, we have found problems that we did not know existed in some of our current patients, and we also have been able to rule out pathologies in other patients whom we believed were suspects. Providing the best care means sending patients for the help they need earlier, and continuing to monitor patients who need ongoing observation." According to Dr. Miller, spectral domain OCT may help eyecare practitioners prevent vision loss by detecting signs of wet AMD earlier. Images from the Cirrus HD-OCT demonstrate AMD progression over a 2-month period "If I diagnose a patient with dry AMD, I have him return based on the severity of AMD at either 6 months or a year, so that I can watch for signs of possible progression, which would trigger a referral to a specialist. But what about the gaps between visits? A patient may develop wet AMD but not recognize he is losing vision for up to 6 months. By the time he comes in for an appointment, he may already have some permanent damage. Having the technology to detect wet AMD earlier can help us save vision."

Aaron Lech, OD, FAAO Dr. Lech graduated from Illinois College of Optometry after earning his bachelor's degree in biology from the University of California, San Diego. Upon graduation, he practiced at Balboa Naval Hospital in San Diego, where he served as Director for both the Optometry Clinic and Specialty Contact Lens Services. In 2004, he relocated to northern California and opened ClearVue Eye Care of Roseville. Jeff D. Miller, OD Dr. Miller is a graduate of the University of Oklahoma and NSU College of Optometry in Tahlequah. After receiving his Doctor of Optometry degree in 1988, he completed a residency in Advanced Diagnosis and Therapeutics of Ocular Disease at the VEF of Oklahoma and NSU College of Optometry. After his residency, Dr. Miller served as Clinic Director and Director of Optometric Education at Triad Eye Medical Clinic and Cataract Institute in Tulsa, Okla. from 1989 to 1994. He then became Center Director for TLC The Laser Center in Tulsa, where he also served as President of TLC's Continuing Education Foundation. In 1999, he went into private practice at Cockrell Eyecare Center in Stillwater, Okla. Dr. Miller and his partners also own and operate the Laser Eye Care Center of Stillwater.