Session Title: FP-16 Vitreoretinal Surgery IV
Session Date/Time: Sunday 14/09/2014 | 11:00-13:00
Paper Time: 11:56
Venue: Boulevard D
First Author: : D.Steel UK
Co Author(s): : K. White
Internal limiting membrane (ILM) peeling during macular hole surgery is thought to improve hole closure partly by removing residual vitreous cortex and persistent traction after vitreoretinal separation. In cadaver eyes with normal vitreo-retinal attachment it has been shown that ocriplasmin results in posterior vitreous separation with a cleaner plane of detachment of the vitreous from the ILM than after spontaneous vitreous detachment. This study was designed to assess the degree of vitreous and cellular debris remaining on the ILM in patients undergoing macular hole surgery who had been given prior ocriplasmin.
Sunderland Eye infirmary in North East England
The ILM from five patients undergoing macular hole surgery for persistently open holes who had previously been given Ocriplasmin were analysed with transmission electron microscopy to assess the extent of vitreous debris present. Ultrathin sections (70nm) were taken at 2 levels through the samples, stained with uranyl acetate and lead citrate and viewed on a Philips CM100 TEM. For estimation of the amount of vitreous collagen and cellular debris, images were taken at x7900 from 14 randomly sampled areas of the ILM. To quantify the amount of debris on each surface of the ILM a grid of lines (line length 2µm) was superimposed on each image. The number of intercepts between the grid line and vitreous surface were counted. Another grid (line length 1µm) was then superimposed on each image and the number of intercepts between the grid lines and any vitreous side debris were counted. The percentage of surface covered by cellular debris was calculated. These were then compared with 18 control patient specimens, matched for age, macular hole size and stage who hadn’t had Ocriplasmin.
All 5 ocriplasmin cases had vitreomacular traction to the edges of the hole pre Ocriplasmin and in 3 of these this persisted up until the time of vitrectomy surgery. In 4 of the 5 patients with previous ocriplasmin the ILM was near devoid of all cellular and vitreous debris compared to 6 of the 18 matched controls. There was a significant difference in the extent of vitreous surface debris between the two groups.
Ocriplasmin may result in a cleaner plane of vitreoretinal separation in patients with full thickness macular holes and vitreomacular traction who fail to close and undergo subsequent vitrectomy surgery. This may have implications for the necessity to peel ILM in these patients.