August 19th is recognized as World Photo Day, an international celebration of photography. This date marks the anniversary of the public unveiling of the Daguerrotype by the French government in 1839. It is an important milestone in the history and evolution of photography.
The story surrounding the invention of photography is both compelling and controversial. Several individuals claimed to be the true inventor of photography. The series of competing announcements by Louis Jacques Mandé Daguerre, William Henry Fox Talbot, and several others became a frantic race filled with secrecy, surprise, jealousy, financial reward, political maneuvering, and legal action.
To this day it’s still not entirely clear who was first to invent photography or exactly when, but history ultimately crowned a winner. Although Talbot (and others) made several significant early contributions Daguerre is generally given credit as the inventor of photography and August 19, 1839 is often recognized as the day that photography was born. Whether or not this is accurate is open to debate, but it seems a good a day as any to celebrate the history and evolution of the photographic arts.
It seems almost too obvious to mention, but just like you can’t see through a window when the window shade is pulled down, you cannot view or image the interior of the eye through closed eyelids.
Obviously we need fully retracted upper and lower lids to get the best view of the fundus with our fundus camera, SLO, or OCT. Because these are noncontact imaging techniques, image quality is also dependent on a regular ocular surface and clear ocular media. An intact tear film is an important optical component of the ocular media. Simply put, to get the best images we need to strike a balance between fully retracted lids and frequent blinking to maintain the tear film.
Many patients are nervous about their visual symptoms and what diagnosis the imaging procedure might detect. They often try hard not to blink during the session thinking it will help you get the best images. But their tear film will break up during this time and the view will become compromised until they blink again. And they often apologize for blinking!
To compound this dilemma, these imaging tests are often performed after a patient has undergone an extensive screening workup that includes IOP measurement, and application of topical anesthetic and dilating solutions. Patients may also undergo gonioscopy or macular contact lens examination prior to imaging. A disrupted tear film is an unintended side effect of these procedures and can adversely affect imaging quality.
It may seem counter-intuitive, but encouraging patients to blink frequently during imaging sessions can improve cooperation and image quality in fundus photography and OCT imaging. In our clinic, patients are often surprised that we encourage them to blink, having had procedures done in other clinics where they were sternly cautioned against blinking. In my experience as a consultant and workshop instructor, I have often heard OCT operators repeat the words “Don’t blink!” while performing a raster scan pattern that may take several seconds to capture.
They know that a blink will result in an artifact in the volume map, but fail to recognize the need for frequent blinking. I don’t really blame the operator. Often that’s how they were taught to perform the scan during a workshop or training session by the manufacturer’s trainer:
No wonder the patients are afraid to blink! Frequent blinking not only refreshes the tear film, it makes the patient feel more comfortable and ultimately more cooperative. You’ll soon learn to recognize a patient’s blinking rhythm and you can time your image capture just as their upper lid is retracting after a blink. Gently encourage the patient by saying, “hold your gaze for just a moment” when you need just a second or two longer to capture a good image. When frequent blinking doesn’t work, application of artificial tears can also make a difference in patients with dry eyes or compromised tear film.
During fundus photography, the flash of the camera will cause an involuntary blink that helps refresh the tear film. If the lid or eyelashes obscure the view, gentle retraction of lids with a finger or q-tip may help. You don’t need to forcefully tug on the lid, just retract it a couple of millimeters to get any lashes out of the way and reveal the entire pupil. Patients are often still able to blink with this mild retraction of the upper lid.
So encourage your patients to blink regularly and learn to capture the best images in between the blinks. If it weren’t for all the blinks, anyone could do this job!
I always look forward to receiving my copy of the the Journal of Ophthalmic Photography in the mail. Even after reading digital proofs as an editor or contributing author it’s great to see the final product in print. There’s just something tangible and authentic about turning the pages of a high quality publication printed on good stock.
I was especially looking forward to the Spring 2016 issue of the JOP. It contains an article I contributed on The Confocal Tonal Shift. What’s unique about this article is that evolved from a blog post here on eye-pix into a scholarly article (of sorts).
The blog was based on an observational series of photographs that documents the tonal changes that occur when focusing the Heidelberg Spectralis, a confocal scanning laser ophthalmoscope (cSLO). I put the blog together to further my own understanding of just what I was seeing with the cSLO, and share my observations with fellow imagers. When asked to convert the blog into a piece for the JOP, I initially felt it was too informal, opinionated, and lacking strong references to be included in the professional literature.
But the kernel of a good idea was definitely there. So I worked backwards and did a literature search after the fact. Then I reworked the article and was able to place my observations into the context of other clinical findings described in the ophthalmic literature. Probably not the ideal way to develop an idea into an article, but in this case it worked.
A mentor of mine has always encouraged me to get as much mileage as possible out of a project. The Confocal Tonal Shift is a good example of that. It’s gone from a blog post to a formal article in a well-respected professional journal. I’ve also adapted it into an expanded lecture topic (The Quirks of Confocal Imaging) that I presented at a recent educational program. It received good feedback and will work it’s way into my lecture rotation this year.
When performing fundus photography or angiography, patients often ask about the technology used to help diagnose their ocular condition. After explaining that it’s a form of photography, the conversation will often turn to cameras. Patients sometimes ask for advice on what type of camera to buy for personal use. Often they’ll tell me about a particular camera they have and will invariably say “the camera takes great pictures”.
I’ve always found this expression and the concept behind it quite amusing. It assumes the person looking through the viewfinder and pressing the shutter button has nothing to do with it! On several occasions these conversations took place at a VA hospital while photographing vets. They’ll talk about having purchased a camera overseas, such as a Voigtlander, Zeiss Contax, or Leica in Europe during WWII, or a Nikon while stationed in Japan, Korea, or Vietnam. Without fail, they’ll tell me that “the camera takes great pictures”. All are quality cameras with good optics, but none of them are capable of taking pictures on their own. Someone has to compose the image and press the shutter.
A related misconception has occurred in ophthalmic imaging over the past decade. With all the automated features such as eye tracking, sampling, auto-alignment and auto-exposure, etc. in the current crop of instruments, there is a perception that retinal imaging is simple and easy to perform. The implication is that the machine takes the picture, not the operator.
It’s true that recent advancements in technology have improved and simplified image capture, but I still believe that skilled photographers produce the best diagnostic images. I once had a conversation with an overly-enthusiastic OCT salesman who claimed his instrument was better than the competition. As proof, he showed me two images of the same patient taken with two different OCT instruments. “See”, he said, “The competition’s instrument missed the pathology”. I corrected him saying that it wasn’t the instrument that missed the pathology, but the operator.
This sparked an interesting debate. I argued that a skilled OCT operator, given appropriate direction from the ordering physician, would not have missed the area of interest. Ultimately we agreed it’s up to the operator to make the best use of the technology they have available.
Several famous photographers have weighed in on the relationship between camera and photographer in producing great images. I love these quotes:
“You don’t take a photograph, you make it.” Ansel Adams
“The camera doesn’t make a bit of difference. All of them can record what you are seeing. But, you have to SEE”. Ernst Haas
“The camera is an instrument that teaches people how to see without a camera.” Dorothea Lange
“Photography is the art of observation… I have found it has little to do with the things you see and everything to do with the way you see them.” Elliot Erwitt
“There is nothing worse than a brilliant image of a fuzzy concept.” Ansel Adams
And finally, whenever someone states, “This camera takes great pictures”, I reply with another common quote that’s been attributed to several people, including boxing trainer Roger Mayweather, basketball great Charles Barkley, and possibly even Confucius:
“It ain’t the tools, it’s the carpenter”.
Voigtlander camera image from Wikimedia Commons: https://en.wikipedia.org/wiki/File:Vitorets.JPG#filelinks
One of the most fundamental yet difficult tasks for beginning photographers is proper adjustment of the focusing reticle of the traditional fundus camera. It is an essential element for capturing consistently sharp retinal photographs. The focusing reticle is the pattern of etched black lines, usually a cross-hair pattern, seen through the fundus camera eyepiece. The reticle is part of an aerial image focusing system like that used in microscopes. An aerial image system is brighter than one that uses a ground glass screen like an SLR camera. In fundus photography the aerial image is important. We need as bright a view as possible to keep the viewing illumination low enough for the patient to tolerate while still being able to see well enough to align and focus the instrument. Yet because the image is focused in “space” rather than on a ground glass, the reticle must match the same plane of focus as the fundus image.
The principle behind this adjustment seems simple enough, but there are some challenges associated with it. Setting the reticle adjusts for simple spherical refractive errors in the observer’s eye when their accommodation is relaxed at distance. You can think of this process as calibration of the optical system prior to focusing the fundus camera. The focus of your eye needs to be set at the same aerial focal plane as the camera. Simply put, both the crosshairs and the fundus need to be in focus at the same time. Set the reticle first and then adjust the focus of the camera.
In order to properly focus the fundus camera on a consistent basis, the photographer should relax their accommodation at distance to avoid accommodative shift during photography. The reticle is then adjusted by turning the eyepiece until the cross hairs are sharp. The barrel of the eyepiece is marked in diopters of correction. Since we are in the eyecare business, many of us know what our refractive error is, and you may be tempted to use that number as your reticle setting. Unfortunately, the diopter numbers may not be accurately marked on the eyepiece and can vary by manufacturer or instrument. So they can’t be relied on when switching from instrument to instrument. The reticle must be set correctly for each instrument.
You also can’t just set the calibration once and be done. A disadvantage to the aerial image is that your eye may change focus due to accommodation. Keeping the cross hair sharp requires constant awareness since your accommodation can change throughout the day due to fatigue or stress. Young photographers may struggle with keeping the eyepiece set properly because they typically have a greater ability to accommodate to near. Early in my career, I often noticed that my eyepiece setting would change as the day went on. It would also change during the week, Mondays were different than Fridays and accommodation also changed with stress levels. Pay constant attention to the cross hairs and adjust the reticle if your accommodation drifts.
If you normally wear glasses or contact lenses, it is usually best to wear them while taking fundus photos rather than rely on the camera eyepiece to correct for your refractive error, especially if you have any astigmatism in your dominant (shooting) eye.
A popular and commonly taught technique for setting the eyepiece reticle involves adjusting the crosshairs at least three successive times, noting the diopter setting each time, and then using the average of these numbers. This technique sounds like a good idea, but it can actually promote unnecessary accommodation and inaccurate settings. Each time the photographer looks at the numbers marked on the eyepiece, they accommodate to near, then immediately try to relax at distance before looking through the viewfinder again. Repeating these steps multiple times induces accommodative “gymnastics” and subsequent fatigue that can lead to improper settings when accommodation inevitably drifts during a photographic session.
For this technique to work properly, someone other than the photographer should note and record the settings, so the photographer can keep accommodation relaxed at distance the entire time.
A better strategy is to ignore the eyepiece numbers altogether, but pay constant attention to the crosshairs and image of the retina. As long as the crosshairs and the aerial image of the fundus both appear sharp at capture, the focus will be correct in a system that is properly calibrated for parfocality.
I recently had the chance to get a hands-on look at the Eidon confocal retinal scanner. The Eidon is a hybrid device combining features of a non-mydriatic fundus camera with confocal scanning technology. It is manufactured in Italy by Centervue SpA. Centervue describes this instrument as the first true color confocal scanner on the market. It is different than a confocal scanning laser ophthalmoscope in that it uses a broad spectrum white light LED (440-650 nm) rather than monochromatic lasers. A second light source provides near infrared (IR) imaging at 825-870 nm. The advantage to confocal imaging is that it suppresses out-of-focus light from reaching the image sensor. This minimizes the effect of cataracts or other media opacities, resulting in sharp, high contrast images. The confocal design also allows it to image through a smaller pupil than a typical non-mydriatic camera.
The footprint of the Eidon is fairly compact, but the instrument is taller than most fundus cameras. The device is operated via touch screen tablet and has both automatic and manual controls. The Eidon has a fixed 60 field of view, but is capable of capturing several fields and creating montage images. It features a 14 megapixel sensor to capture color, red free, and infrared images. The red free photos are extracted from the color image rather than through a separate exposure with a blue-green light source.
The capture software is incredibly simple to use. It is about as automatic as a device can get. Using the touch screen tablet, you enter the patient demographics and program it for the desired fields of one or both eyes and push the start button. The device does the rest automatically, even telling the patient to open their eyes prior to each flash capture.
The internal fixation light will step through the various fields and capture each one automatically. Auto-alignment is accomplished by identifying the center of the patient’s pupil with IR. It will then focus automatically with a range of -12D to +15D. Once focused in IR, the camera will slightly readjust focus just prior to color capture to account for the difference in wavelengths between color and IR. The autofocus works very well, but eye movement during capture can contribute a slight blur to the image.
Minimum pupil size is 2.5mm. It does capture good images at this pupil size in the posterior pole view but like any other non-myd device, it works a little better if patients are pharmacologically dilated. This is especially helpful when imaging peripheral fields or you plan to do a montage. I have found this to be true with all non-myd color fundus cameras. I would like to see separate exposure settings to reduce the gain and noise for eyes with widely (pharmacologically) dilated pupils.
The resulting images appear different than what we see with either a digital fundus camera or a cSLO. Centervue refers to the broad spectrum imaging as “True Color” to distinguish Eidon images from SLO composite laser color images from Spectralis or Optos.
The Eidon attempts to address some of the limitations of digital fundus cameras that are poorly calibrated for color balance, gamma, and exposure. In doing so, it seems to sacrifice some color fidelity and a true appearance of the optic nerve. The red channel is desaturated to avoid loss of detail from oversaturation, but many Eidon images appear slightly green and might benefit from a little more red or magenta bias to the color balance.
Although the pixel count of the Eidon sensor is quite high, the color images seem a little over-processed and a bit noisy when zoomed in, probably from the increased contrast as well as the high gain settings that allow it to capture through very small pupils.
One of the features touted by the manufacturer is that it prevents “optic disc bleaching” seen with some fundus cameras. It does hold detail in optic disc photos, but the flip side to this is that the rim of the nerve can appear abnormally dark or gray, making it difficult to document pallor. Disc bleaching shouldn’t be a problem in fundus cameras that are calibrated for proper contrast and exposure.
I also played with the digital joystick and manual mode changing the level of focus to see if the instrument exhibited the confocal tonal shift seen with the Spectralis. In playing with manual mode to alter focus or exposure, it became clear that the instrument works best in full-auto mode.
The Eidon review software is functional, but could be a little more streamlined. It would be nice to scroll though successive images, rather than having to go back and forth to the proof sheet to open each frame individually. The montage software works quite well.
The bottom line is that the Eidon is a very interesting hybrid device that combines features of confocal scanning with full color capture in a package that is incredibly simple to use. It would be a great screening tool or replacement for a fundus camera in primary eye care settings and would require minimal staff expertise or training.
Thanks to Todd Hostetter, CRA, COMT for bringing the device to the clinic for a demo, and to Jim Strong, CRA, OCT-C for help taking some of the images.
Disclaimer: I have no financial or proprietary interest in this device.
The Heidelberg Spectralis confocal scanning laser ophthalmoscope (cSLO) is a commonly used diagnostic imaging device that uses monochromatic laser illumination to image the eye. It can be used for several retinal imaging modalities including infrared reflectance (IR), fluorescein angiography, ICG angiography and fundus autofluorescence (FAF). The confocal capability of the cSLO allows it to capture high-contrast, finely detailed images.
But what does confocal actually mean and how does it work? The word confocal simply means “having the same focus”. In this case it refers to the confocal pinhole or aperture that is optically located at the same plane of focus as the subject. The cSLO utilizes a focused laser to scan the subject point-by-point and then captures the reflected light after it passes through a confocal pinhole. The pinhole suppresses out-of-focus light from reaching the image detector resulting in very sharp images. The confocal pinhole is especially effective at eliminating unwanted scatter from cataracts or corneal opacities since these structures fall far outside the plane of focus.
When imaging a patient, you can see the confocal effect as you adjust the focus to the plane of the retina where it is most light efficient. The image on screen will get brightest just as you come into sharpest focus. A secondary effect of the confocal aperture is how it effects the appearance of elevated or out of focus retinal structures.
Adjusting the focus knob of the Spectralis can have a dramatic effect on the tonal appearance of elevated structures such as papilledema or vitreous floaters as seen here in this video.
Note the optic nerve get progressively darker as focus is adjusted from the peak of the nerve to the surface of the surrounding retina, which starts to appear brighter. The opposite occurs in the second example. Vitreous floaters from asteroid hyalosis appear as dark shadows when focus is set on the optic nerve. As focus is shifted up into the vitreous, the floaters begin to brighten and the retina fades to dark. The brightness/exposure has not been adjusted during this tonal shift. The only change is the focus.
So what does this mean for us as diagnostic imagers? Because of the inherently shallow depth of focus of the cSLO, some ocular structures may appear dark simply because they are slightly out of focus. Elevated serous detachments or papilledema are examples of this phenomenon that I call the confocal tonal shift.
In some cases the confocal tonal shift can enhance the diagnostic information by clearly outlining the borders of an elevated area or lesion. The effect is most notable with the IR laser and in red free mode.
The confocal tonal shift also has the potential to create tonal “artifacts” which can confound the appearance of findings like blood or hemorrhage that inherently appear dark. Vitreous opacities will appear dark because they are usually out of focus and blocked by the confocal pinhole. But are they from blood or vitreous debris? It’s impossible to tell with the cSLO since they appear the same even though one is translucent and one is more opaque when viewed ophthalmoscopically or with a fundus camera.
Similarly, it is difficult to distinguish between blood and elevation within retinal tissues in conditions such as macular degeneration, retinal vein occlusions and diabetic macular edema.
It is important to note that elevated lesions can appear dark regardless of the pathologic location in the fundus. cSLO imaging alone can’t always differentiate the anatomic location. OCT imaging or angiography may be necessary to further investigate the location of the pathology.
In some cases, the the confocal pinhole may suppress light that is reflected from the actual plane of focus, but is slightly blurred because of scattering from a lesion in tissue that is normally clear.
Although originally designed to image the retina, the cSLO can also be used to image the front of the eye. The confocal tonal shift may also effect the appearance of some anterior segment findings.
In addition to the confocal shift, light scattering from some corneal lesion types may also be suppressed by the pinhole contributing to the dark appearance of the lesion.
It is important to understand the confocal density shift when capturing or interpreting cSLO images and differentiate between structures that truly are dark from those that are simply out-of-focus. In some cases the tonal shift enhances areas of interest that may not be easily identified by other means. In others it may confound the documentation of blood or hemorrhage. A second imaging modality such as color fundus photography, OCT or angiography is often needed to present a more complete diagnostic imaging study.
Over the past decade, fundus autofluorescence imaging has become a commonly used diagnostic technique to document the presence of fluorescent structures in the eye.1-2 The term “autofluorescence” is used to differentiate fluorescence that may occur naturally from fluorescence that is derived from application of dyes such as fluorescein or indocyanine green.
Autofluorescence is most commonly used to document fluorescence of lipofuscin, a fluorescent pigment that accumulates in the retinal pigment epithelium (RPE) as a normal byproduct of cell function.3 Lipofuscin deposition normally increases with age, but may also intensify in certain retinal abnormalities. It is used to document progression of macular degeneration, central serous chorioretinopathy, Stargardt disease, drug toxicities, and several hereditary retinal dystrophies.
In addition to the documentation of lipofuscin in the RPE, there are other fluorescent findings that may occur in the eye. One of the initial uses of autofluorescence was documenting optic disc drusen and astrocytic hamartomas as early as the 1970’s.4 Both of these entities are calcified lesions that are highly fluorescent and can be documented with standard fluorescein excitation and barrier filters.
In addition to these well-known entities, there are some additional autofluorescent findings you may encounter in the eye. In 2009, Utine et al reported autofluorescence of pingueculae on the ocular surface.5 This finding may interfere with photo-documentation of topical fluorescein staining patterns in patients with conjunctival lesions.
Certain emboli, presumably calcific, exhibit fluorescence.
We’ve also had a case of corneal blood staining that fluoresced. As it turns out, hemoglobin and hemosiderin are known to be fluorescent and that’s what fluoresced in this case.
There may be other ocular findings that exhibit autofluorescence when excited with light of specific wavelengths. Have you noticed anything else that fluoresces? If so, I encourage you to share them.
von Ruckman A, Fitzke FW, Bird AC. Distribution of fundus autofluorescence with a scanning laser ophthalmoscope. Br J Ophthalmol 1995;79:407-412.
Spaide RF. Fundus autofluorescence and age-related macular degeneration.
Delori FC, CK Dorey CK, G Staurenghi G, et al. In vivo fluorescence of the ocular fundus exhibits retinal pigment epithelium lipofuscin characteristics. Invest Ophthalmol Vis Sci 1995;36:718-729.
Kelly JS. Autofluorescence of drusen of the optic nerve head. ArchOphthalmol 1974;92: 263-264.
Utine CA, Tatlipinar S, Altunsoy M, et al. Autofluorescence imaging of pingueculae. Br J Ophthalmol 2009;93:396–399.
On a recent trip through Virginia, I stumbled across a gem of a museum tucked away in historic downtown Staunton, VA. I had been browsing brochures of local attractions on a stand in the lobby of my hotel and spotted a photo of a vintage view camera. The brochure was for the Camera Heritage Museum. The non-profit museum bills itself as the largest camera museum on the East Coast. It wasn’t far from my hotel, so I decided to visit, not knowing what to expect.
I walked into what obviously had once been a camera store jam-packed with cameras of all shapes, sizes and vintages. There was a gentleman sitting behind a counter in the back, busy doing some maintenance on a camera. He looked up briefly, said hello, and went back to his work while I browsed through the impressive collection. I saw everything from miniature spy cameras to large format portrait view cameras.
I recognized some cameras that I had used in my early days in photography including a Crown Graphic 4×5 press camera, a Graphic View (first monorail view camera design), several early polaroid cameras, a 16 mm Minox and many others.
After a few minutes of browsing, I asked the man behind the counter a few questions about some cameras that I recognized. When I showed genuine interest in the cameras on display, he stepped out and started describing the history, significance and stories related to many of the items on display. His name was David Schwartz, and he is the curator of the museum. He’s a wealth of information. As more people entered the museum, he recounted some of the same stories several times over, each time with the enthusiasm of someone that clearly loved cameras and the history of photography.
The collection includes vintage view cameras, military cameras, spy cameras, aerial cameras, stereo cameras, underwater cameras, Kodak Brownies, Hasselblads, Leicas, Voigtlanders, Nikons, and some truly unique cameras including a 40″ long baseball camera with lever activated focus stops preset for the distance to each of the bases on the diamond.
David and I talked about some of the stereo cameras on display and I told him that as a medical photographer I regularly take stereo photos of human retinas. He nodded and directed me to a case which held a collection of Topcon 35mm cameras including a body from a vintage Topcon fundus camera.
When I explained a little bit more about fundus photography, he listened intently and I can imagine that he’ll include some of what I told him about this equipment in explanations to future museum visitors.
The venue for this museum is a little quirky, but it houses a serious collection of over 2000 cameras, photos and accessories. A unique feature is the fact that it is an open and accessible to the public, rather than a private collection. The museum also has an online presence. Their website contains a wealth of information on the history of photographic equipment, especially the online gallery of some of the many cameras in their collection. It’s a great resource for history buffs and vintage camera enthusiasts.
The museum can be found at the old Camera and Palette store at 1 West Beverley Street in Staunton, VA. If you are travelling through the area, it is definitely worth a visit. Better yet, if you have some old film cameras collecting dust in a closet you might want to consider contributing to the collection by donating them to the museum. They are always looking for cameras, photos and accessories with historic significance.
Did you ever wonder how ophthalmic diagnostic findings get their names? If you feel like there is no rhyme or reason to the naming conventions used in ophthalmology, you are not alone. Ophthalmology (and medicine in general) does not have structured system of nomenclature like some other sciences.
For example, the field of chemistry utilizes the periodic table of elements to organize and classify fundamental information. Biology employs Linnaean Taxonomy, which is an organized hierarchical system of classification including kingdom, phylum, class, order, family, and genus, to differentiate and name species. It was established and organized by Carl Linnaeus in the mid 1700’s and results in a naming convention known as binomial nomenclature.
In binomial nomenclature, this common Tiger Swallowtail butterfly is known as Papilio Glaucus. It was classified and named by Linnaeus himself in 1758. Papilio is latin for butterfly and glaucus means blue.
Human anatomy and medicine is a different story however. Historically there has been controversy, disagreement, language differences, and confusion amongst anatomists regarding universal terminology. To address this, there have been attempts to standardize terminology in human anatomy. Nomina Anatomica was the international standard on human anatomic terminology from 1956 until it was replaced by Terminologia Anatomica in 1998. But in ophthalmology, as in much of medicine, there is no universal system of classification for ocular anatomy, clinical findings, or diseases. It’s a bit of a “free-for-all”. In the late nineteenth century some 50,000 terms for various body parts were in use. The same structures were described by different names, depending on the anatomist’s background: school, language, culture, traditions, etc.
Let’s take a look at some of the ways that diseases are named in ophthalmology. Clinical findings may be named for their anatomic location, clinical appearance, etiology, disease process, or end result. They may also be based on etymologic roots or finally, eponyms.
A common and logical diagnostic naming convention is simply descriptive of a disease process like vitreomacular traction or corneal erosion.
Or it could be the anatomic result of those processes such as a macular hole that results from vitreomacular traction or a corneal ulcer that arises from erosion.
Some terms are based on clinical appearance, either the literal appearance or a resemblance to something else. Pink eye or floppy lid syndrome are conditions that are literally descriptive of their appearance.
Conditions like bear tracks, bullseye maculopathy, cotton wool spots, morning glory nerve, birdshot choroidopathy, and several others often bear a resemblance to something that would be commonly recognized or understood.
Other names may be based on etymology, which means they originate from traditional Greek or Latin root words.Heterochromiais a good example as it comes from the Greek roots heteros which means different, and chroma which means color.
Cataractis an interesting term that may be related to the opaque lens’ resemblance to rushing water of a waterfall, or possibly to one of the earlier etymologic roots meaning a covering or impediment.
Some conditions are probably better known by the acronym representing the full name: ARN, CHRPE, APMPPE, etc.
Finally, many conditions are based on eponyms meaning they are named for a person, usually the person that first identified or described the condition in the literature. Eponyms are a longstanding tradition in science and medicine, and being awarded an eponym is considered an honor.
Anatomists seem to have been especially fond of naming structures for themselves as seen by the many eponymous anatomic terms in ophthalmology: Bowman’s Membrane, Descemet’s Membrane, Canal of Schlemm, Annulus of Zinn, Schwalbe’s Line, Tenon’s capsule, and Bruch’s Membrane to name just a few.
Eponyms extend beyond anatomy into diagnoses as well. Conditions have been named for Sjögren, Krukenberg, Stargardt, Marfan, Elschnig, Thygeson, Vogt, Cogan and countless others. We certainly shouldn’t overlook Austrian ophthalmologist Ernst Fuchs, who described several conditions and has his eponym associated with many of them. Eponyms may also be proper names of places ( Lyme Disease, North Carolina Macular Dystrophy) or famous patients: Lou Gehrig’s Disease (amyotrophic lateral sclerosis) or Tommy John surgery (named for Major League pitcher, first person to undergo the procedure).
With all these names and egos involved, there has often been confusion and controversy over who was the first to fully describe a condition. Bergmeister’s papilla and Mittendorf dot are eponyms given to remnants of opposite ends of the embryonic hyaloid artery. Vogt-Koyangi-Harada disease is named for three investigators who independently described different manifestations of the same underlying condition. Stevens-Johnson syndrome, named for pediatricians Albert Mason Stevens and Frank Chambliss Johnson, also has several other eponyms associated with it including names such as: Baader, Fiessinger, Rendu, Fuchs, Klauder, Neumann and Hebra – whew! Further confusing things are hyphenated or double surnames such as Robert Foster-Kennedy (Foster-Kennedy syndrome ) and Roger Wyburn-Mason (Wyburn-Mason syndrome).
In fact, Wyburn-Mason syndrome had been previously described in the French literature and is also known as Bonnet-Dechaume-Blanc syndrome. So the correct eponym may depend on what language you speak.
Eponyms are often controversial, especially when questions arise about the moral and ethical character of eponymous honorees. There has been sparring in the literature for years over the use of eponyms and the worthiness of some of the individuals that have conditions named for them. Pulido and Matteson ask the question, “Is it worth having eponyms at all?” in an editorial in Retina in 2010. They go on to state, “Although they can function as a memory aid, they do not enhance understanding of disease…. It is best henceforth to not name new diseases with eponyms and to start moving away from their use completely.”
“The current trend is away from the use of eponymous disease names, towards a medical name that describes either the cause or primary signs.”
“The scientific and medical communities regard it as bad form to attempt to eponymise oneself.”
Then there is Stigler’s Law of Eponymy, which states, “No scientific discovery is named for the original discoverer.” As proof, Stigler freely admits that others postulated the idea before he named it for himself! In describing Stigler’s Law, Malcolm Gladwell stated, “We think we’re pinning medals on heroes. In fact, we’re pinning tails on donkeys.”
David Cogan talked about the pitfalls and limited life of eponymous designations in an editorial in the Archives of Ophthalmology in 1978. Yet Cogan-Reese syndrome was named for him and Algernon Reese many years ago.
When a new designation, ICE syndrome, was suggested as a unifying term to replace Cogan-Reese syndrome, Chandler syndrome, and essential iris atrophy, Cogan was quoted by William Spencer in another editorial in Archives: “Better a descriptive name, if that is possible, and an eponym if it is not possible. Now the syndrome described by Al Reese and me is characterized by nodules, unilateral glaucoma, Descemet’s membrane and endothelial extension; why not call it by the acronym NUDE syndrome? This would give it sex appeal and put the Archives right up there with Esquire.” Cogan’s response suggests he thought eponyms still have their place – especially when it came to one named for himself!
Surprisingly, these trends and opinions haven’t prevented the coining of new eponyms in ophthalmology. In 2013, a new anatomic layer of the human cornea was first described by Harminder Dua in the journal Ophthalmology. There was even a big splash in the mainstream scientific news and social media about this exciting new discovery and the investigator who identified it. As you may have already guessed, the finding is called Dua’s layer. He named it for himself!
Despite all the controversies, confusion, and egos involved, it seems as if eponyms in ophthalmology are here to stay, at least for now. So try not to be confused or frustrated when comparing Fuchs’ corneal dystrophy with Fuchs’ heterochromic iridocyclitis, or if you have difficulty remembering whether it is Best’s or Behcet’s disease that has macular vitelliform lesions. We might as well embrace these long-established eponyms – warts and all.
Resources Here are some great resources to look up information on eponyms in medicine and ophthalmology: