Bill Harvey: Stained class
Author: Bill Harvey
In last week’s issue, as part of the feedback on our dry eye VRICS exercise, I wrote: ‘Most authorities advise the use of this green stain in dry eye assessment. Unlike rose Bengal which causes ocular irritation, lissamine green is well tolerated making it the preferred choice in optometric practice. It shows a high level of affinity in staining degenerated cells, dead cells and mucous fibrils. As such, it is a useful stain in monitoring chronic disease.’
This week, the GOC clarified the legal position on the use of lissamine green by UK clinicians (see https://standards.optical.org/lissamine-green/). They stated: ‘It is the view of the Clinical Consensus Panel based on the evidence available and practice and clinical opinion, that lissamine green is clinically safe to use and that optometrists and contact lens opticians in the UK may within their scope of practice use a CE marked lissamine green impregnated ophthalmic strip for clinical investigations of the ocular surface until further notice.’ It is good to know, as I am sure many of us were using it anyway.
Another anterior eye issue also came to the fore last week. Demodex infestation as a cause of persistent blepharitis is something unheard of just a few years ago. The fact that most of us carry the mite and that it can secure itself around the base of the eyelashes to aggravate the lid is well worth knowing, especially now that a number of tea tree oil based preparations are available to aid treatment. A nice paper in last month’s Cornea journal (February 11 issue) has highlighted how it is perfectly possible to visualise (and presumably image) the mite in situ using just a slit-lamp and a few easy to find accessories (90D Volk lens, fine forceps, fluorescein strips, saline, a glass slide and coverslip, adhesive tape, and a piece of white paper). This Blue Peter approach is well worth trying.
But I suspect this is no longer the infection de jour…