Most up to date ophthalmology practices now incorporate digital slit lamp cameras into their equipment armamentarium. Not only does the technology allow for precise comparison and follow up of disease processes through time, but also it can be an effective learning/teaching tool in-house and for meetings.
An article written by Kumar S, et al, in 2009 solidified the value in slit lamp digitography. Their results confirmed that digital images showed moderate to excellent agreement to clinical findings (kappa 0.45-0.82) in areas other than lid pathologies. Lens findings from digital images had moderate to good agreement with the clinical gold standard (unweighted kappa 0.43-0.65, sensitivity 59-77%, specificity 86-94%) and gross cornea signs were well detected with digital image.
Dr. Goldman recently posted a technology spotlight, "Digital Slit Lamp Camera Systems: How to Decide", directing viewers on how to decide which camera system to choose. He discussed built in systems versus adaptors, complimentary metal-oxide semiconductor (CMOS) versus charge-coupled devices (CCD), as well as imaging software. This article will act as a supplement, discussing some of the different systems and advantages to each.
Built-in Units:
Haag-Streit
- CM 900
Haag-Streit makes its own slit lamp digital imaging system. The CM 900 is designed to fit the BP 900 and the BD 900 slit lamp and has picture and high-resolution video capabilities. This unit has a 'freeze technology' that allows high-speed capture and data transfer. As well, you can rewind time and freeze the moment via the 'history trigger'.
- IM 900
Made to fit the BQ 900 slit lamp, the IM 900 imaging module also offers still imaging and high resolution video, freeze technology, and history trigger. It also has precise image control and depth of field control.
Oculus
- ImageCam 2
The ImageCam 2 by Oculus allows a slit lamp image or video sequence to be taken by the high resolution, digital video camera in the beam path of the slit lamp. It can be attached to any common slit lamp on the market. The software lends to ease of adjustments in exposure time, light magnification and white balance. There is control of depth of field that projects images live on a monitor. This system also comes with a loupe function.
Topcon
- DC-3
The DC-3 is exclusively designed for the Topcon SL-D slit lamp series. It can take still and video images with an integrated 8.3 megapixel camera and 1 megapixel video capture. This unit comes with the basic IMAGEnet i-base software, the patient database management tool.
Kowa
- VK digital slit lamp Imaging System
This digital imaging system features video display and capture replay as well as still frame capture from both live and recorded video. It utilizes the VK-2 imaging software. The system also comes with a super mini-PC system hardware and OS, a pole mounted widescreen LCD, one touch foot pedal for image capture and storage and two touch foot pedal for live video image capture, a high resolution sony CCD "firewire" digital camera, and a CD/DVD drive. It is compatible with most Marco, Zeiss, Topcon and Haag-Streit slit lamps.
Adapters:
TTI Medical
TTI offers digital image capture packages for surgical microscopes and slit lamps. They are adaptable to Zeiss, Leica, Moller-Wedel, Haag-Streit, Global, Seiler, Aus Jena, Kaps, Topcon, Vasconcellos, Marco, Takagi, Rodenstock and Inami. 
- 8001-2
This package is the Canon EOS DSLR camera upgrade package consisting of the Canon DSLR camera adapter, canon T2i, beam splitter, LED illuminator, software for importing images and digital HD video recording and a USB footswitch for image capture. There is a 3 or 5 step magnification changer.
- 8001-1
This package comes with the TTI Imaging USB camera, f65 direct coupler, software, a USB footswitch, and LED background illuminator.
Zarf Enterprises
Zarf's digital SLR slit lamp lens adapter is used for Nikon digital SLR cameras and Haag-Streit BM900 or B900 slit lamps. These adapters slide into the slit lamp eye piece lens tube and attaches directly onto the camera via the included T-mount ring adapter. 
They also make similar adapters for Canon digital cameras. The series of adapters, depending on which model you get, will fit onto Burton 825, 830, or 835 slit lamps, Marco IIB, IIB Ultra or V slit lamps, Topcon SL1, SL3, SL3C, SL3D, or SL3E slit lamps as well as Haag-Streit slit lamps.
Whatever slit lamp you have in your practice, there is a digital camera unit for you, whether you are on a budget and want to use an existing digital camera that is mounted onto your slit lamp, or whether you want a built-in system.