scholarly journals Indications for intraoperative anterior segment optical coherence tomography in corneal surgery

2020 ◽  
Vol 40 (10) ◽  
pp. 2617-2625 ◽  
Author(s):  
Stefan J. Lang ◽  
Sonja Heinzelmann ◽  
Daniel Böhringer ◽  
Thomas Reinhard ◽  
Philip Maier

Abstract Purpose Recently, intraoperative optical coherence tomography (iOCT) has evolved in the field of ophthalmic surgery. So far, the use of iOCT was mainly focused to lamellar keratoplasty, especially deep anterior lamellar keratoplasty (DALK) and Descemet membrane endothelial keratoplasty (DMEK). The aim of this study was to report our experiences with iOCT to introduce new possibilities of this application. Methods We used iOCT in 18 patients who underwent the following surgeries: DALK, DMEK, penetrating keratoplasty, autologous limbal transplantation, transscleral suture fixation of a posterior chamber lens, pannus removal on corneal surface and newborn investigation in Peters’ anomaly. We obtained qualitative video data for all procedures. Results With the iOCT, the cannula placement during DALK preparation of the recipient cornea and bubble formation could be visualized to improve the success rate of the big bubble injection. In DMEK, the iOCT enables the visualization of Descemet’s membrane removal in the recipient and graft orientation as well as better control of graft attachment. The iOCT enables intraoperative visualization of the graft–host interface during penetrating keratoplasty. During autologous limbal transplantation, transscleral suture fixation of a posterior chamber lens and removal of corneal surface pannus the iOCT is capable of showing the thickness of lamellar preparations to avoid penetrations and to save healthy recipient’s tissue. Conclusion The iOCT is a helpful device for intraoperative anterior segment imaging not only for DALK and DMEK. It is also beneficial in penetrating keratoplasty and every other form of lamellar preparation during corneoscleral surgery.

2019 ◽  
Author(s):  
Yujin Zhao ◽  
Hong Zhuang ◽  
Jiaxu Hong ◽  
Lijia Tian ◽  
Jianjiang Xu

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.


2020 ◽  
Author(s):  
Yujin Zhao ◽  
Hong Zhuang ◽  
Jiaxu Hong ◽  
Lijia Tian ◽  
Jianjiang Xu

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.


2019 ◽  
Author(s):  
Yujin Zhao ◽  
Hong Zhuang ◽  
Jiaxu Hong ◽  
Lijia Tian ◽  
Jianjiang Xu

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.


1988 ◽  
Vol 19 (6) ◽  
pp. 396-398
Author(s):  
Alan V Spigelman ◽  
Richard L Lindstrom ◽  
Bruce D Nichols ◽  
Thomas D Lindquist ◽  
Stephen S Lane

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