Description

The Eye with Central Retinal Vein Occlusion: to laser or not to laser

Central retinal vein occlusion is a common cause of visual loss in the elderly. In addition, a significant number of eyes with CRVO may develop discomfort, pain and redness from rubeosis iridis. (see Kinshuck et al).

There are currently two schools of thought as to how the eye with CRVO should be managed. One recommends that the eye should be kept comfortable by medical means and watched, but not touched with laser. The other, which is more widely accepted, recommends application of retinal laser photocoagulation. The first school has only few proponents or supporters. Fortunately most UK Ophthalmologists support and advocate the use of laser photocoagualtion in eyes with ischaemic CRVO.

The general recommendation is that eyes with ischaemic CRVO should be watched and, at the earliest sign of rubeosis iridis, receive pan retinal laser photocoagulation (2000 to 3000 burns of 500 micron spot size). Some ophthalmologists, however, would advocate lasering all eyes with ischaemic CRVO at first sight without waiting for development of iris neovascularization. This practice, however, would require laser application to twice (or more) as many eyes than would develop rubeosis and painful eyes. Furthermore, laser absorption is limited in the acute phase of central retinal vein occlusion on account of retinal haemorrhages and oedema. One would recommend therefore that if patient compliance with follow-ups is satisfactory laser photocoagulation be applied only at the first sight of iris or retinal new vessels.

The eye with significant macula oedema may be treated with grid laser photocoagulation.

More recently induction of chorioretinal vascular shunts by intense focal laser burns has been advocated. The rationale of this treatment is that shunting would allow the obstructed retinal vein to drain into the choroidal circulation. The results reported so far have been discouraging. Furthermore, the potential complications of florid choroidal neovascularization (which were quite predictable) have been reported with increasing frequency. It is therefore advised at this time that such treatment should not be recommended to patients en masse. It would be prudent for the general ophthalmologist to await the results of a proper trial of laser induced chorioretinal anastomosis.

The search for other treatments for central retinal vein occlusion continues.