Needle Depth and Big-Bubble Success in Deep Anterior Lamellar Keratoplasty

Pasricha, Neel D; Shieh, Christine; Carrasco-Zevallos, Oscar; Keller, Brenton; Cunefare, David; Farsiu, Sina; Izatt, Joseph A.; Toth, Cynthia A.; Kuo, Anthony N.

doi:10.1097/ico.0000000000000948

Cited by 36 publications

(33 citation statements)

References 36 publications

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“…Few studies have described the feasibility of intraoperative OCT to DALK. 18,19,23 Thus, the combination of existing intraoperative OCT and our device would make a great impact on microsurgery, which requires the precise manipulation of a needle as well as the continuous observation of a surgical region.…”

Section: Discussionmentioning

confidence: 99%

“…11,12 Moreover, it is difficult to predict the visual outcome because of the presence of uneven residual stromal thickness. 13,14 To assist the sophisticated big-bubble formation, the use of intraoperative optical coherence tomography (iOCT) [15][16][17][18][19] or iOCT with a surgical microscope [20][21][22][23] imaging system has been considered for the DALK procedures. Monitoring the needle's manipulations in the cornea can safely handle a sharp needle and better determine the injection point with knowledge of the depth.…”

Section: Introductionmentioning

confidence: 99%

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Lamellar keratoplasty using position-guided surgical needle and M-mode optical coherence tomography

et al. 2017

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, "Lamellar keratoplasty using position-guided surgical needle and M-mode optical coherence tomography," J. Biomed. Opt. Abstract. Deep anterior lamellar keratoplasty (DALK) is an emerging surgical technique for the restoration of corneal clarity and vision acuity. The big-bubble technique in DALK surgery is the most essential procedure that includes the air injection through a thin syringe needle to separate the dysfunctional region of the cornea. Even though DALK is a well-known transplant method, it is still challenged to manipulate the needle inside the cornea under the surgical microscope, which varies its surgical yield. Here, we introduce the DALK protocol based on the position-guided needle and M-mode optical coherence tomography (OCT). Depth-resolved 26-gage needle was specially designed, fabricated by the stepwise transitional core fiber, and integrated with the swept source OCT system. Since our device is feasible to provide both the position information inside the cornea as well as air injection, it enables the accurate management of bubble formation during DALK. Our results show that real-time feedback of needle end position was intuitionally visualized and fast enough to adjust the location of the needle. Through our research, we realized that position-guided needle combined with M-mode OCT is a very efficient and promising surgical tool, which also to enhance the accuracy and stability of DALK. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Lamellar keratoplasty using position-guided surgical needle and M-mode optical coherence tomography

et al. 2017

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“…The motor with lead screw weighs less than 15 g. Using a pitch of 0.5 mm, gear ratio of 64:1, and 400 encoder steps (with quarter counts), the positioning resolution of the needle drive is 1.25 µm (beyond that of the OCT sensor). Based on previous research, various insertion angles have been used, such as 60 • , 75 • and even close to 90 • from vertical [8,9,16] for visibility and improved control. Our device sets the angle to 60 • to preserve a reasonable SNR of the OCT sensor since these other factors aren't as much of a concern in the automated procedure.…”

Section: Oct Distal Sensor Integrated Needlementioning

confidence: 99%

“…The key to a successful full big-bubble formation is the precise depth control of the needle insertion. Many surgeons believe the needle must get as close as possible to DM, which could be interpreted as 90+% corneal depth without perforation [14][15][16]. Since it was first demonstrated in 1991 [17], optical coherence tomography (OCT) has emerged as a leading technology for ophthalmic visualization, especially for retinal structures [18] and been widely applied to ophthalmic surgery and research [19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

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

Guo

Sarfaraz

Gensheimer

et al. 2020

Sensors

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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.

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“…A popular method for separating the stroma from Descemet’s membrane involves an intrastromal air injection 6, 7 , termed the Big Bubble (BB) technique, which creates an air bubble between these layers. Aside from needle depth 8 and residual stromal bed 9 , little is known about the factors that affect the success of BB formation, including intraocular pressure (IOP).…”

Section: Introductionmentioning

confidence: 99%

Intraocular Pressure and Big Bubble Diameter in Deep Anterior Lamellar Keratoplasty: An Ex-Vivo Microscope-Integrated OCT With Heads-Up Display Study

Bhullar

Carrasco-Zevallos

Dandridge

et al. 2017

Asia Pac J Ophthalmol (Phila)

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Purpose To investigate the relationship between intraocular pressure (IOP) and big bubble (BB) formation in an ex-vivo model of deep anterior lamellar keratoplasty (DALK). Design Ex-vivo Methods Corneo-scleral buttons from human donors were loaded onto an artificial anterior chamber connected to a column of balanced salt solution. A surgeon-in-training learned to perform DALK via the BB technique using swept-source microscope-integrated optical coherence tomography (SS-MIOCT) with heads-up-display (HUD). DALK procedures were performed at six different IOPs (5, 10, 15, 20, 30, or 40mmHg; n=6 per group) in a randomized fashion, with the surgeon-in-training masked to the pressure and guided by SS-MIOCT with HUD. For a subset of corneas within each pressure group, DALK was performed on matching donor tissue at a control IOP. BB diameter was recorded, and a diameter exceeding the trephine diameter was considered optimal. Results Wilcoxon rank sum test showed a difference in BB diameter amongst the different pressure groups (mean±standard deviation of 7.75±1.60mm, 8.33±1.99mm, 10.9±0.92mm, 9.08±1.07mm, 6.67±3.33mm, and 3.42±3.77mm in the 5, 10, 15, 20, 30, and 40mmHg groups, respectively; p=0.0014). Per Tukey test, this difference was attributable to comparisons between the 40mmHg group and the 5, 10, 15, or 20mmHg groups (p=0.04, 0.02, 0.0001, 0.004, respectively). Conclusion In this ex-vivo model of DALK, the BB technique guided by SS-MIOCT with HUD, yielded bubbles of optimal diameters only at physiologic pressures (10–20mmHg). Extremely high IOP (40mmHg) resulted in BBs of significantly smaller diameter than BBs obtained at physiologic and low (5mmHg) IOPs.

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Needle Depth and Big-Bubble Success in Deep Anterior Lamellar Keratoplasty

Cited by 36 publications

References 36 publications

Lamellar keratoplasty using position-guided surgical needle and M-mode optical coherence tomography

Lamellar keratoplasty using position-guided surgical needle and M-mode optical coherence tomography

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

Intraocular Pressure and Big Bubble Diameter in Deep Anterior Lamellar Keratoplasty: An Ex-Vivo Microscope-Integrated OCT With Heads-Up Display Study

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