1046hrs: Retinal Detachment (William Ross)
/Full Professor here at UBC who has run the retina fellowship program for many years.
Starts with discussion of Gonin’s Principle; recognition that retinal break was the cause of the detachment. Closure of the break cures the detachment.
Pathogenesis of detachment reviewed. Liquid vitreous getting through the tear with RP pump trying to drain it and traction of vitreous on the retina opposes this.
Pneumatic retinopexy: if superior break. Gas bubble occludes the break and the RP pump draws out the subretinal fluid. Cryo done around tear which can scar later; sometimes supplement with laser. If however too much vitreous traction, this can still pull retina off later. This technique is least invasive of all but does also require proper patient positioning. Fluid can shift and lead to new breaks however.
Scleral buckling: some people think no longer needed. However, scleral buckle has been the benchmark for RD repair. Position buckle to close the tear; rarely need to drain subretinal fluid at time of surgery as long as buckle on the tear. The explant (buckle) helps relieve the vitreous traction forces. No use of gas to cause cataracts, no travel restriction as no gas to expand, no cataract formation as eye not invaded internally.
Retinal dialysis: usually in young people from trauma. Circumferential band often needed. Usually takes 2-4 years for this to occur as vitreous liquifies. Must close the dialysis with the buckle. Unfortunately, as often such a slow progression to detach, the prognosis is guarded. However, totally preventible if caught early.
Combined scleral buckle and vitrectomy: RD with superior and inferior breaks. Dr Ross prefers encircling bands to provide additional support. Worth the extra 15 minutes; then proceed with the vitrectomy now that traction is relieved. Shows video. 360 degrees of laser to prevent future detachment. If phakic, patient will get a cataract for sure. Don’t like primary vitrectomy for people under 50 if possible.
Giant retinal tear: peripheral break extending >90 degrees. Need to infuse “heavies” to posterior pole starting at optic nerve to push the retina flat. In the end, replace with fluid then C3F8. Shows movie of this.
PVR: total RD with PVR, retina is getting foreshortened. Trouble is that membranes forming not just on top but also underneath the retina. Silicone Oil needed and stays in place for 3-4 months. Unfortunately, sometimes retina so foreshortened that you have to cut it to release the subretinal traction. Another video shown.
Quiz: 40 yo male with breaks post and inferiorly. People respond with scleral buckle.
Next quiz: massive PVR; need to cut the retinal breaks.
Another: total detachment but just one break superiorly. Definitely try pneumatic first.
Last case: toxo in the eye, macula still on, break below inferior arcade. 13 yo male. Sponge is the way to go on this one.