‘Acute-angled bevel’ sign to assess donor lenticule orientation in ultra-thin descemet stripping automated endothelial keratoplasty

Abstract

A 6.5-year-old boy with congenital hereditary endothelial dystrophy underwent clear corneal ultra-thin descemet stripping automated endothelial keratoplasty (DSAEK). After graft insertion, it was difficult to assess graft orientation due to hazy cornea. Intraoperative optical coherence tomography (iOCT) showed a well-attached graft and the bevelled edge of donor lenticule made an acute angle with the overlying stroma. Postoperative anterior segment OCT confirmed the presence of acute-angled bevel sign. A wetlab experiment was performed with experimental corneoscleral tissues to confirm the findings. Donor lenticule was injected in the artificial chamber with stromal-side up as well as stromal side-down. ‘Acute-angled bevel sign’ was observed on iOCT in the experimental cases with stromal-side up. In inverse graft, the acute-angled bevel was not observed, instead the configuration was obtuse angled. Identifying the ‘acute-angled bevel sign’ on iOCT confirms correct graft orientation after unfolding and is extremely useful for hazy corneas and ultrathin DSAEK lenticules.

Microscope Integrated Optical Coherence Tomography Guided Descemet Stripping Automated Endothelial Keratoplasty in Congenital Hereditary Endothelial Dystrophy

“…Acuteangled bevel sign could also be useful in confirmation of the graft orientation in these cases. 31 The mean final visual acuity in our study group is poorer than the final acuity of other studies. 2 This could be attributed to late presentation leading to thicker and hazier corneas and poorer presenting visual acuity compared to other studies.…”

“…Acute-angled bevel sign could also be useful in confirmation of the graft orientation in these cases. 31 …”

What Is the Impact of Intraoperative Microscope-Integrated OCT in Ophthalmic Surgery? Relevant Applications and Outcomes. A Systematic Review

“…Thirty-one articles were excluded: 19 were not written in English, 9 were review papers, and 3 were ex vivo studies. After full-text evaluation, 82 studies discussing the use of MI-OCT in ophthalmology were included [ 13 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , ...…”

“…When the graft is well-attached with the stromal side up, the lenticule bevelled edge forms an acute angle with the overlying stroma, named the “acute-angled bevel sign”. This is especially useful in hazy cornea, where it is hard to confirm graft orientation [ 33 ].…”

Dye-based identification of the orientation of tissue for Descemet stripping automated endothelial keratoplasty: A laboratory-based study

“…[ 5 ] Techniques like double-ring sign aid in identifying lenticule orientation after insertion into anterior chamber (AC). [ 6 7 8 9 10 11 12 ] However, loss of orientation can occur even before its insertion into AC, commonly with ultra-thin lenticules and novice-surgeons. [ 13 14 15 ] Though rare, this could compel the surgeon to replace the tissue, which is undesirable given the preexisting dearth of donor corneas.…”