scholarly journals Optical Coherence Tomography Guided Robotic Needle Insertion for Deep Anterior Lamellar Keratoplasty

2020 ◽  
pp. 1-1
Author(s):  
Mark Draelos ◽  
Gao Tang ◽  
Brenton Keller ◽  
Anthony Kuo ◽  
Kris Hauser ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Needle Insertion ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Optical Coherence ◽  
Anterior Lamellar Keratoplasty

scholarly journals Demonstration of Optical Coherence Tomography Guided Big Bubble Technique for Deep Anterior Lamellar Keratoplasty (DALK)

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 428
Author(s):  
Shoujing Guo ◽  
Nicolas R. Sarfaraz ◽  
William G. Gensheimer ◽  
Axel Krieger ◽  
Jin U. Kang
Keyword(s):  
Optical Coherence Tomography ◽  
Rejection Rate ◽  
Cell Loss ◽  
Needle Insertion ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Optical Coherence ◽  
Insertion Depth ◽  
Anterior Lamellar Keratoplasty ◽  
Big Bubble

Deep anterior lamellar keratoplasty (DALK) is a highly challenging procedure for cornea transplant that involves removing the corneal layers above Descemet’s membrane (DM). This is achieved by a “big bubble” technique where a needle is inserted into the stroma of the cornea down to DM and the injection of either air or liquid. DALK has important advantages over penetrating keratoplasty (PK) including lower rejection rate, less endothelial cell loss, and increased graft survival. In this paper, we successfully designed and evaluated the optical coherence tomography (OCT) distal sensor integrated needle for a precise big bubble technique. We successfully used this sensor for micro-control of a robotic DALK device termed AUTO-DALK for autonomous big bubble needle insertion. The OCT distal sensor was integrated inside a 25-gauge needle, which was used for pneumo-dissection. The AUTO-DALK device is built on a manual trephine platform which includes a vacuum ring to fix the device on the eye and add a needle driver at an angle of 60 degrees from vertical. During the test on five porcine eyes with a target depth of 90%, the measured insertion depth as a percentage of cornea thickness for the AUTO-DALK device was 90.05 % ± 2.33 % without any perforation compared to 79.16 % ± 5.68 % for unassisted free-hand insertion and 86.20 % ± 5.31 % for assisted free-hand insertion. The result showed a higher precision and consistency of the needle placement with AUTO-DALK, which could lead to better visual outcomes and fewer complications.

scholarly journals Malapposition of Graft-host Interface after Penetrating Keratoplasty (PK) and Deep Anterior lamellar Keratoplasty (DALK): an optical coherence tomography study

2019 ◽  
Author(s):  
Yujin Zhao ◽  
Hong Zhuang ◽  
Jiaxu Hong ◽  
Lijia Tian ◽  
Jianjiang Xu
Keyword(s):  
Optical Coherence Tomography ◽  
Penetrating Keratoplasty ◽  
Corneal Transplantation ◽  
Anterior Segment ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Optical Coherence ◽  
Visual Outcomes ◽  
Total Prevalence ◽  
Anterior Lamellar Keratoplasty

Abstract Backgroud: Previous studies of internal graft-host malappositions have not dealt with the precise ways in which each malapposition affected post-penetrating keratoplasty (post-PK) visual outcomes. In this study, we reviewed our post-PK and post-deep anterior lamellar keratoplasty (post-DALK) keratoconic patients and used anterior segment optical coherence tomography (AS-OCT) to evaluate the correlations between graft-host interface (GHI) characteristics and visual outcomes. Methods: Novel GHI metrics included: mean graft-host touch (GHT), total prevalence of malapposition proportion (Pm), frequency of apposition (F), size of malapposition (Sm), junctional graft thickness (Tg), and the absolute value of difference between Tg and Th (|Tg-Th|). We connected the external and internal junction points of GHI (GHT) and drew a straight line through the central point, perpendicular to both sides of the cornea. Tg and Th were the thicknesses at cross-points 1 mm away from the meeting point on the external side of the graft and host, respectively. Correlations between GHI metrics and postsurgical visual outcomes [ logarithm of minimum angle of resolution best-corrected visual acuity (logMAR BCVA), spherical equivalent diopter (SE), diopter of spherical power (DS), diopter of cylindrical power (DC) and keratometric astigmatism (Astig value)] were evaluated for 45 patients (one eye each). Results: 22 post-PK and 23 post-DALK keratoconic patients were enrolled. Compared with the regular-apposition results, GHT was decreased in step and gape patterns, and increased in hill and tag patterns. SE increased by 6.851, 5.428 and 5.164 times for every 1% increase in: F (step) [b=6.851; 95% Confidence interval (CI)=2.975-10.727; P=0.001]; F (graft step) [b=5.428; 95% CI=1.685-9.171; P=0.005]; and Pm [b=5.164; 95%CI=0.913-9.146; P=0.018], respectively. SE increased by 0.031 times for every 1-μm increment of |Tg-Th| [b=0.031; 95% CI=0.009-0.054; P=0.007]. LogMAR BCVA increased by 0.001 times for every 1-μm increment of both GHT [b=0.001; 95% CI=0-0.002; P=0.030]. and Tg [b=0.001; 95% CI=0.001-0.002; P=0.001]. Astig value increased by 0.017 times for 1-μm increment of Sm [b=0.017; 95% CI=0-0.033; P=0.047]. Conclusion: This investigation of GHI characteristics suggests explanations for varied ametropia in keratoconic eyes and has potential significance as a reference for promoting pre-surgical planning and technology for corneal transplantation.

scholarly journals Malapposition of Graft-host Interface after Penetrating Keratoplasty (PK) and Deep Anterior lamellar Keratoplasty (DALK): an optical coherence tomography study

2020 ◽  
Author(s):  
Yujin Zhao ◽  
Hong Zhuang ◽  
Jiaxu Hong ◽  
Lijia Tian ◽  
Jianjiang Xu
Keyword(s):  
Optical Coherence Tomography ◽  
Penetrating Keratoplasty ◽  
Linear Regression Analysis ◽  
Corneal Transplantation ◽  
Anterior Segment ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Optical Coherence ◽  
Visual Outcomes ◽  
Anterior Lamellar Keratoplasty

Abstract Backgroud: Previous studies of internal graft-host malappositions have not dealt with the precise ways in which each malapposition affected post-penetrating keratoplasty (post-PK) visual outcomes. In this study, we reviewed our post-PK and post-deep anterior lamellar keratoplasty (post-DALK) keratoconic patients and used anterior segment optical coherence tomography (AS-OCT) to evaluate the associations between graft-host interface (GHI) characteristics and visual outcomes. Methods: Novel GHI metrics included: mean graft-host touch (GHT), total prevalence of malapposition proportion (Pm), frequency of apposition (F), size of malapposition (Sm), junctional graft thickness (Tg), junctional host thickness (Th) and the absolute value of difference between Tg and Th (|Tg-Th|). We connected the external and internal junction points of GHI (GHT) and drew a straight line through the central point, perpendicular to both sides of the cornea. Tg and Th were the thicknesses at cross-points 1 mm away from the meeting point on the external side of the graft and host, respectively. Linear regression analysis was used to describe associations between GHI metrics and postsurgical visual outcomes [ logarithm of minimum angle of resolution best-corrected visual acuity (logMAR BCVA), spherical equivalent diopter (SE), diopter of spherical power (DS), diopter of cylindrical power (DC) and keratometric astigmatism (Astig value)]. Results: We enrolled 22 post-PK and 23 post-DALK keratoconic patients. Compared with the regular-apposition results, GHT was decreased in step and gape patterns, and increased in hill and tag patterns. SE increased averagely by 6.851, 5.428 and 5.164 diopter per 1% increase in: F (step) [β=6.851; 95% Confidence interval (CI)=2.975-10.727; P=0.001]; F (graft step) [β=5.428; 95% CI=1.685-9.171; P=0.005]; and Pm [β=5.164; 95%CI=0.913-9.146; P=0.018], respectively. SE increased averagely by 0.31 diopter per 10-μm increment in |Tg-Th| [β=0.031; 95% CI=0.009-0.054; P=0.007]. LogMAR BCVA increased (on average) by 0.01 per 10-μm increment in both GHT [β=0.001; 95% CI=0-0.002; P=0.030]. and Tg [β=0.001; 95% CI=0.001-0.002; P=0.001]. Astig value increased on average by 0.17 diopter per 10-μm increment in Sm [β=0.017; 95% CI=0-0.033; P=0.047]. Conclusion: This investigation of GHI characteristics suggests explanations for varied ametropia in keratoconic eyes and has potential significance as a reference for promoting pre-surgical planning and technology for corneal transplantation.

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