Optical or video, which specifications change clinical practice, what else the room needs, and where a screening pathway breaks after the instrument arrives. Written for gynaecology departments starting or expanding a colposcopy service.
Cervical cancer is among the most common cancers affecting women in Bangladesh, and it is one of the few cancers where screening reliably catches disease at a treatable stage. Colposcopy sits at the centre of that pathway: it is what happens after a screening test flags an abnormality, and it determines whether the right tissue is biopsied. The equipment decision is therefore a clinical one, not a furnishing one, and it is made badly often enough to be worth setting out properly.
A colposcope is a stereoscopic magnifying instrument with its own illumination, used to examine the cervix after the application of acetic acid or iodine. Its job is narrow and specific:
Both are in current clinical use and the choice depends on how the department works rather than on which is newer.
| Optical (binocular) | Video / digital | |
|---|---|---|
| How the clinician views | Through binocular eyepieces, stereoscopic | On a monitor, usually two-dimensional |
| Strength | Depth perception, immediate, nothing between eye and tissue | Whole team sees the same image; natural documentation and teaching |
| Documentation | Needs a camera attachment to record | Capture is built into the workflow |
| Best suited to | Experienced colposcopists, high-volume clinics | Teaching hospitals, screening programmes, multidisciplinary review |
Many departments end up with both: an optical instrument in the main clinic and a video system where images need to be shared, reviewed or used for training. A number of optical colposcopes accept a camera attachment, which gives a route to documentation without replacing the instrument.
Within the optical family there are two configurations that behave very differently in a busy outpatient department. An instrument on a mobile wheeled stand can serve two or three couches; the same optics mounted permanently on the treatment chair cannot move but never has to be repositioned, aligned or found. Modular systems such as the Karl Kaps KP 3000/3000s, which offer both configurations with identical optics, let a department choose per room rather than per hospital, and let lighting, magnification and documentation modules be added later as the service grows. On the video side, a Full HD unit such as the Karl Kaps ViCo S HD, combining camera and LED lighting in one compact head, with autofocus holding the image sharp and an electronic green filter switched in at the touch of a button, removes most of the fiddling that puts clinicians off digital systems.
Colposcopy is done across a range of magnifications rather than at one setting. Lower magnification gives the overview needed to orient and see the whole transformation zone; higher magnification is used to assess vessel patterns in a suspicious area. Specify an instrument with a stepped or continuous magnification change rather than a single fixed power, and check that changing magnification does not require refocusing every time. A three-step changer covers routine screening work; a continuous zoom is worth the money in a unit that also teaches.
A green filter absorbs red light, which makes blood vessels appear dark against a pale background. Abnormal vascular patterns such as punctation and mosaicism are considerably easier to identify with it. It is a small, inexpensive feature and it is genuinely diagnostic, so it should be treated as mandatory rather than optional on any colposcope bought for screening work.
LED illumination has largely replaced halogen. It runs cooler, which matters for patient comfort during a procedure that already causes anxiety; it lasts far longer, which matters where lamp replacement is difficult; and it holds colour temperature stable, which matters because acetowhite change is judged by colour. Daylight-quality, colour-accurate illumination is not a marketing line here, it is the thing the diagnosis rests on.
The stand determines how usable the instrument is day to day. Floor stands on castors suit a room where the colposcope moves between couches. Swing arm and wall mounts save floor space in a small OPD room. Tripod mounts suit outreach work. Whatever the type, the deciding question is whether the arm holds position without drift once set, because an instrument that creeps during an examination is a permanent irritation and, eventually, a reason the instrument stops being used.
A screening programme that cannot show what it saw cannot audit itself. Image capture allows a second opinion without recalling the patient, comparison at follow-up to judge whether a lesion has progressed, quality assurance across colposcopists, and training of new clinicians on real cases. For any hospital running a formal screening pathway, documentation capability should be in the specification from the start rather than added after the programme has been running blind for two years.
A colposcopy room needs an examination or gynaecological table with proper lithotomy positioning and adjustable height, a good task light independent of the colposcope, an instrument trolley, a suction unit, and specimen handling provision for biopsies. Ordering the colposcope alone leaves the room incomplete, and the missing items are usually discovered on the first clinic day. Where each of those items belongs in the room is set out in colposcopy room layout and patient flow.
Most screening programmes in Bangladesh start with visual inspection with acetic acid at the primary level and refer positives onward. The equipment failure everyone plans for is the colposcope breaking down. The pathway failure that actually loses patients is the one nobody buys equipment for: a woman screened positive in a camp who is referred to a district hospital and never arrives, or a biopsy sent to pathology whose result never gets back to the woman who gave it.
So when you specify the service, specify the register alongside the instrument. Who records the referral, who confirms attendance, who chases the result, and how long each of those steps is allowed to take. A colposcopy clinic that sees everyone referred to it and loses half of them afterwards is doing detection, not screening.
Colposcopy is an interpretive skill. The same instrument in trained and untrained hands produces different clinical outcomes, and equipment cannot compensate for the gap. Budget for structured training when a department starts colposcopy, and prefer suppliers who provide clinical application support at handover rather than delivering a box. Ask, before the order, who will attend the first clinic list with the team and how long they will stay.