Article

Use of Intraoperatiye Fourier-Domain Anterior Segment Optical Coherence Tomography During Descemet Stripping Endothelial Keratoplasty

University Hospital Zurich, Department of Ophthalmology, Frauenklinikstrasse 24, Zurich, Switzerland.
American Journal of Ophthalmology (Impact Factor: 4.02). 09/2010; 150(3):360-365.e2. DOI: 10.1016/j.ajo.2010.04.017
Source: PubMed

ABSTRACT To evaluate the intraoperative use of handheld Fourier-domain optical coherence tomography (OCT) during Descemet stripping automated endothelial keratoplasty (DSAEK) to assess the donor-host interface.
Prospective, observational case series.
Six patients undergoing DSAEK surgery were included. OCT scans of the cornea were performed intraoperatively after insertion of the donor disc, after instillation of air in the anterior chamber beneath the disc, after vent incisions in the host cornea in each quadrant, following air-fluid exchange at the end of operation, and on day 1 after surgery. The central 3 mm of each cornea was scanned. The broadest gap between donor and host cornea (interface space) was measured.
Adequate readings could be obtained from all patients without any complications. In 2 patients there was a decrease in the width of the interface space after each surgical step documented by the OCT scans. At the end of their operation, no interface space was detectable. In 2 patients, interface space disappeared after the vent incisions and did not reappear during the further course of the surgery. In further 2 patients the separation between the host and donor was still detectable at the end of the operation. All patients had no detectable interface gap on day 1.
Handheld anterior segment OCT can be used to assess the host-donor interface in lamellar corneal transplantation surgery. Donor adherence can occur in spite of residual interface space at the end of surgery. Further studies should be conducted to answer the question of which surgical steps are useful in assisting with donor adhesion.

Download full-text

Full-text

Available from: Stephanie Louise Watson, Sep 22, 2014
0 Followers
 · 
89 Views
  • Source
    • "Early applications of iOCT used portable OCT systems to provide intraoperative visualization either through a handheld, externally mounted, or microscope-mounted systems [2]–[4], [6]–[11]. Novel designs for handheld ophthalmic imaging systems have also been presented, which use state-of-the-art light-sources or multimodality imaging, and have potential applications in intraoperative imaging by improving imaging speed and ergonomics [14], [15]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose To demonstrate key integrative advances in microscope-integrated intraoperative optical coherence tomography (iOCT) technology that will facilitate adoption and utilization during ophthalmic surgery. Methods We developed a second-generation prototype microscope-integrated iOCT system that interfaces directly with a standard ophthalmic surgical microscope. Novel features for improved design and functionality included improved profile and ergonomics, as well as a tunable lens system for optimized image quality and heads-up display (HUD) system for surgeon feedback. Novel material testing was performed for potential suitability for OCT-compatible instrumentation based on light scattering and transmission characteristics. Prototype surgical instruments were developed based on material testing and tested using the microscope-integrated iOCT system. Several surgical maneuvers were performed and imaged, and surgical motion visualization was evaluated with a unique scanning and image processing protocol. Results High-resolution images were successfully obtained with the microscope-integrated iOCT system with HUD feedback. Six semi-transparent materials were characterized to determine their attenuation coefficients and scatter density with an 830 nm OCT light source. Based on these optical properties, polycarbonate was selected as a material substrate for prototype instrument construction. A surgical pick, retinal forceps, and corneal needle were constructed with semi-transparent materials. Excellent visualization of both the underlying tissues and surgical instrument were achieved on OCT cross-section. Using model eyes, various surgical maneuvers were visualized, including membrane peeling, vessel manipulation, cannulation of the subretinal space, subretinal intraocular foreign body removal, and corneal penetration. Conclusions Significant iterative improvements in integrative technology related to iOCT and ophthalmic surgery are demonstrated.
    PLoS ONE 08/2014; 9(8):e105224. DOI:10.1371/journal.pone.0105224 · 3.23 Impact Factor
    • "Time-domain anterior segment OCT can provide images with a tissue resolution ranging from 5 to 17 μm with an imaging depth varying from 2.3 to 6 mm, while the Fourier-domain OCT with the corneal adaptor module provides images with a tissue resolution of 5 μm and an imaging depth of 2.3 mm.12 In the literature, Fourier or spectral-domain OCT with CAM has been used mostly to evaluate corneal thickness, LASIK flaps and anterior chamber angle structures.356789101112131415 There is relative paucity of information on the limitations of imaging common corneal and conjunctival pathologies with Fourier-domain OCT with CAM. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: To describe the limitations of Fourier-domain optical coherence tomography (OCT) in imaging common conjunctival and corneal pathology. Materials and Methods: Retrospective, single-center case series of 40 patients with conjunctival and cornea pathology. Results: Fourier-domain OCT imaged laser in situ keratomileusis (LASIK) flaps in detail, including its relation to other corneal structures and abnormalities. Similarly, in infectious or degenerative corneal disorders, Fourier-domain OCT successfully showed the extent of infiltration or material deposition, which appeared as hyper-reflective areas. In cases with pterygium, the underlying cornea could not be imaged. All cases of common conjunctival pathologies, such as nevus or pinguecula, were successfully imaged in detail. Nevi, scleritis, pterygium, pinguecula, and subconjunctival hemorrhage were hyper-reflective lesions, while cysts and lymphangiectasia were hyporeflective. The details of the underlying sclera were not uniformly imaged in conjunctival pathologies. Fourier-domain OCT imaged the trabeculectomy bleb in detail, whereas the details of structures of the anterior chamber angle were not routinely visualized in all cases. Conclusions: Light scatter through vascularized, densely inflamed, or thick lesions limits the imaging capabilities of Fourier-domain anterior segment OCT.
    Middle East African journal of ophthalmology 07/2014; 21(3):220-4. DOI:10.4103/0974-9233.134673
  • Source
    • "In an observational study, interface fluid was quantified intraoperatively during DSAEK using a handheld Fourier-domain OCT (Bioptigen Inc, Durham, NC), which has a resolution of 10 μm. Knecht et al showed that after donor insertion with the Busin glide and subsequent venting, donor adherence can occur in spite of residual interface fluid of less than 0.2 μm.19 The use of a higher resolution SD-OCT of 5 μm in the present study indicates that donor adherence is possible even when up to 5 μm of interface fluid is present centrally. "
    [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the intraoperative changes in the donor lenticule, recipient cornea, and the reduction of interface fluid thickness during Descemet's stripping and automated endothelial keratoplasty with EndoGlide™ (Angiotech Pharmaceuticals Inc, Vancouver, Canada) donor insertion, using intraoperative spectral-domain optical coherence tomography. Prospective observational case series of patients underwent Descemet's stripping and automated endothelial keratoplasty using the EndoGlide inserter. Spectral-domain optical coherence tomography (iVue; Optovue Inc, Fremont, CA) with a handheld probe was used to image the cornea and anterior chamber. Standardized software was used to measure interface fluid gap, host cornea, and donor lenticule thicknesses during the following surgical stages of Descemet's stripping and automated endothelial keratoplasty: (1) after donor insertion and immediately before full air tamponade; (2) after air tamponade and expression of fluid from venting incisions; (3) at 6 minutes of air tamponade; and (4) at 10 minutes of air tamponade. Ten patients with a mean age of 74.9 ± 11.8 years were recruited. Spectral-domain optical coherence tomography measurements of the interface fluid gap after fluid was expressed through the venting incisions (P < 0.001), at 6 minutes of air tamponade (P < 0.001) and at 10 minutes of air tamponade (P < 0.001 and P = 0.001, respectively), were significantly decreased compared to the measurements immediately before air tamponade. Donor thickness increased significantly at 6 minutes of air tamponade (P = 0.004) but reduced by 10 minutes compared to immediately before air tamponade. Significant intraoperative changes in the donor, recipient cornea, and interface fluid thickness occurred following endothelial keratoplasty donor insertion.
    Clinical Ophthalmology 03/2012; 6:479-86. DOI:10.2147/OPTH.S28971 · 0.76 Impact Factor
Show more