Slit Lamp Photography on a Shoestring Budget
An economical approach
to enhancing patient care and a practice's cash flow.
HOLT, O.D., Ogden, Utah
suspect that most optometrists in practice currently do not incorporate digital
photography into their exams. Digital cameras are perceived to be very expensive
and therefore cost prohibitive. True anterior segment cameras can cost over $15,000
and fitting a camera to an existing slit lamp can cost over $5,000. Additionally,
the practitioner might not be fully aware of how, when, or why to bill for this
truly valuable procedure.
From top to bottom: 1. The "macro" setting
is used without the slit lamp to document the correct placement of an Optech aniridia
IOL (photo courtesy of Scott Sykes, M.D.) 2. A corneal erosion is easily seen
here and documented to monitor healing, as well as for patient education. 3. The
progression of corneal neovascularization can be closely followed. 4. A brunescent
cataract is photographed with an optic section. 5 This post-LASIK SPK is well documented
through the slip lamp with a cobalt filter.
Trial and error
In optometry school I tried to take slit lamp photos with my digital
camera without success. I had given up on anterior segment photography that
was, until I did some research and subsequent trial and error on my own.
returned to anterior segment photography following some of the techniques that others
had found successful. After trying several cameras, I purchased the Cannon PowerShot
SD300 Elph. Its resolution is 4.0 megapixels and with a 512 MB Secure Digital (SD)
card, it will hold 255 images at "best" quality. The camera itself is not much bigger
than a cassette tape. At a cost of just over $350 with the additional memory card,
the camera paid for itself after eight photos. Regardless of the camera you choose,
an important feature is the "macro" mode. This is the camera's ability to focus
at very close distances. My camera has a macro focus at as close as 3 cm, perfect
for both slit lamp photos and external close photos of the eye and periocular structures.
The proper settings
Several of the settings need to be adjusted for optimal slit lamp
photography. Depending on your specific camera, these may differ slightly. The camera
needs to be set to "center focus." This is often done by simply changing from the
auto to the manual mode. The focus seems to be better if a transilluminator is used
to illuminate the eye in addition to the slit beam. Be sure to switch the flash
off, this will often give you far too much light. Switch the camera to the "macro"
mode. With my camera, this is indicated by a small flower shape on the top of the
I consistently take better photos when I turn the "ISO speed"
to 400. This allows for higher quality images in dim illumination and minimizes
blur from an unsteady patient or camera. It is also important to keep your printer
in mind. If you plan to print photos, despite camera quality, your photo will only
be as good as your printer. At our practice we use an Epson photo ink jet. It has
card ports for every kind of memory card, so no special connectors are needed and
the quality is exceptional.
Once the settings are correctly adjusted, use a slit lamp to focus
the area of interest just as during an exam. Instruct the patient to fixate on a
point and try not to move. Lock the slitlamp into position. I tend to take better-focused
photographs when I set a transilluminator on the slit lamp table. It lights the
area of interest in addition to the slit lamp beam. The camera is then brought up
to the ocular. Either the right or the left one will work fine. Once up to the ocular,
the camera lens needs to be roughly one inch from the ocular in order to maintain
an optimal field of view. A finger works well, both as a stabilizer and a spacer.
It can be difficult to feel comfortable doing this at first, but with practice,
it becomes much easier. I take several photos in order to secure two or three good
photos for printing in their chart.
Coding and billing
When you bill, the reimbursement will differ slightly for each
insurance carrier. The Medicare approved fee for 99285 is roughly $43.50. Keep in
mind that this is a unilateral procedure. If you are going to document a condition
in each eye you will need to use modifier 50. Also keep in mind that in order to
bill for this, you must generate an interpretation and report separate from the
original chart note. Ethical coding does play an important role in anterior segment
The indications for this type of procedure are very specific to
track the progression or lack of progression in an ocular condition, or to track
the progression of a particular course of treatment. While many conditions can be
photographed, photo-documentation should not be used to simply document the presence
of an ocular finding. (A table listing the appropriate diagnoses to photograph can
be found on the "Web Exclusive section" of optometricmanagement.com.)
If a provider sees only four cases each week that called for
photo documentation, it would create over $9,000 in positive cash flow each year
not to mention the additional patient care and education provided. With photographs,
you are able to show patients exactly what their eyes looks like. By not just using
a generic model eye, you increase the patient's understanding of what you see and
the proposed plan of action.
Photography also helps to market your practice. Patients can take
copies of the photos to show to friends and family. You can include copies in letters
back to referring physicians. These can all lead to more patient referrals and increased
The bottom line
Photography has allowed us to augment the patient's medical records
by not simply relying on drawings to follow ocular conditions. Patients have expressed
the value of really seeing what we are referring to when we explain to them their
corneal ulcer, neovascularization, cataract, or what ever the case may be. In addition
to this patient benefit, you can increase the care you give and create additional
Dr. Holt is in group practice at the Mount Ogden
Eye Center and Bountiful Hills Eye Center. He completed a residency at the University
of Utah Moran Eye Center and Veterans Hospital. He can be reached at
Optometric Management, Issue: October 2005