Session Title: Vitreoretinal Surgery I
Session Date/Time: Thursday 17/09/2015 | 08:30-10:30
Paper Time: 08:46
First Author: : D.Steel UNITED KINGDOM
Co Author(s): : A. Karimi K. White
PURPOSE:To evaluate the staining and handling characteristics, and effect on internal limiting membrane (ILM) histology of two heavier than water ILM specific dyes during macular hole surgery: Acid violet 17 combined with 5% mannitol (AV17-M) (Ala purple, Alamedics, Germany and Brilliant Blue G with 4% polyethylene glycol (BBG - PEG) (ILM blue, DORC, The Netherlands).
Sunderland Eye Infirmary, Northern England, UK
The ILM of consecutive patients undergoing surgery for idiopathic macular hole were stained with BBG-PEG and AV17-M for 10 seconds each, and subjective surgeon graded score of the staining reaction and ease of ILM peeling recorded using visual analogue scales. The ILMs were retrieved and examined with transmission electron microscopy (TEM). The thickness of the ILMs were measured and extent of retinal side debris scored. Surgical videos were used to assess the staining contrast effect by measuring the Euclidean distance in the CIELAB colour space between stained and unstained retina after peeling. A xenon light source was used for all surgeries (Constellation, Alcon, USA)
54 consecutive patients were studied with 27 in each group. The mean age of the patients was 72 years and 38 (70%) were female with no significant difference between the groups. There was no significant difference between the groups for macular hole size, the presence of VMT or Gass stage 4 classification. The amount of retinal side tissue was greater on the BBG-PEG stained ILMs compared to the AV17-M stained ILMs (29.3% versus 19%, p less than 0.001). There was no difference in ILM thickness between the two dyes (2.96 microns versus 2.87 microns, p=0.64). Subjectively the ILM was slightly but not statistically significantly easier to peel in the BBG-PEG group (7.2 versus 6.4, p=0.07). There was a significant difference in the subjective staining appearance by the surgeon (7.2 versus 5, p less than 0.001) and in the CIELAB colour space euclidean separation distance between stained and peeled retina (5.63 versus 3.94, p less than 0.001) in favour of BBG-PEG. All holes were closed postoperatively and visual outcomes between the two groups were not significantly different (logMar visual acuity 0.38 versus 0.43, p=0.34)
Both stains were successfully used in all cases to peel ILM with outcomes comparable to the published literature. AV17-M resulted in less retinal debris than BBG-PEG suggesting an altered and beneficial ILM cleavage plane from the retina but with lowered staining contrast than BBG-PEG. Further study into ILM cleavage plane modulation would be of interest.