In vivo corneal high-speed, ultra high-resolution optical coherence tomography

Abstract

Objective: To introduce new corneal high-speed, ultra-high-resolution optical coherence tomography (hsUHR-OCT) technology that improves the evaluation of complicated and uncomplicated cataract, corneal, and refractive surgical procedures.

Design: This case series included a control subject and 9 eyes of 8 patients who had undergone phacoemulsification, Descemet membrane stripping endokeratoplasty, corneal implantation for keratoconus, and complicated and uncomplicated laser in situ keratomileusis. These eyes underwent imaging using a prototype ophthalmic hsUHR-OCT system. All the scans were compared with conventional slitlamp biomicroscopy.

Results: Cross-sectional hsUHR-OCT imaging allowed in vivo differentiation of corneal layers and existing pathologic abnormalities at ultrahigh axial image resolution. These images illustrate the various incisional and refractive interfaces created with corneal procedures.

Conclusions: The magnified view of the cornea using hsUHR-OCT is helpful in conceptualizing and understanding basic and complicated clinical pathologic features; hsUHR-OCT has the potential to become a powerful, noninvasive clinical corneal imaging modality that can enhance surgical management.

Trial registration: clinicaltrials.gov Identifier: NCT00343473.

Figures

Figure 1

Control subject. Commercially available time-domain optical coherence tomography (A) and high-speed, ultra–high-resolution optical coherence tomography (B) images of a healthy human cornea in vivo. Note the high reflectivity centrally and especially at the tear-epithelial interface, where the light signal is greatest.

Figure 2

Laser in situ keratomileusis (LASIK) trauma. A and B, A corneal epithelial defect at the 5-o'clock position with surrounding diffuse lamellar keratitis (DLK) of the inferotemporal flap. The arrow encompasses the epithelial defect where the foreign body was removed (seen as densely high reflectivity on high-speed, ultra–high-resolution optical coherence tomography [arrow]), surrounded by an area of dense DLK. C, Increased reflectivity of the temporal LASIK flap interface (right) adjacent to the most severe area of DLK. The nasal flap interface (left) is not as hyperreflective.

Figure 3

Complicated laser in situ keratomileusis (LASIK). A, Trauma to the LASIK flap resulted in a diaphanous sheet of epithelial ingrowth under the flap (arrows). B, Epithelial in-growth under a LASIK flap that appears as a space-occupying, high-reflectivity area in the stromal flap interface (arrows). C and D, Eight weeks after epithelial ingrowth removal, only residual high reflectivity is noted at the temporal extent of the LASIK flap interface, representing trace stromal scarring. (Note that the signal intensity is greater at the endothelial surface per the scanning setting for this case.)

Figure 4

Fluid cleft syndrome. A, Diffuse corneal haze secondary to endothelial cell deficiency. B, High-magnification slitamp biomicroscopy revealed fluid clefting in the laser in situ keratomileusis (LASIK) flap interface (arrows). C, Hyporeflective slit due to accumulation of aqueous fluid is seen on high-speed, ultra–high-resolution optical coherence tomography along the LASIK flap interface (arrows).

Figure 5

Descemet membrane stripping endokeratoplasty. A, On postoperative day 1, 50% air bubble fill in the anterior chamber helps with adherence of the transplant. B, Magnified slitlamp view of the high-reflectivity donor-host interface (arrow). C, The interface between the recipient and donor corneas is marked by arrows. High-speed, ultra–high-resolution optical coherence tomography shows the strongest light signal approaching the epithelial surface. In addition to the proximity to the strongest light signal the patient's own corneal tissue is edematous and hyperreflective secondary to Fuchs endothelial dystrophy. The inner donor stromal–Descemet membrane–endothelial transplant is clearly seen as hyporeflective behind the hyperreflective donor-host interface. The donor and original corneas are seen in full adherence.

Figure 6

Iridocorneal touch. A, Dense corneal arcus obscuring slitlamp biomicroscopic details of a deep lamellar keratoplasty transplant in the inferior region. B, Magnified slitlamp view of the area of iridocorneal attachment (arrow) obscured under the corneal arcus. C, High-speed, ultra–high-resolution optical coherence tomography shows the area of the attachment (right) and the hyporeflective area between the donor-recipient interface (arrows).

Figure 7

Intrastromal corneal implant A, Polymethyl methacrylate corneal implant ring placed at the corneal stroma. B, The hyporeflective space of the corneal implant ring appears in two-thirds corneal depth. Adjacent areas of high reflectivity correspond with “stretching” and altering normal corneal lamellar architecture and spacing. Folding of the cornea seen in the left upper-hand corner is a scanning artifact.

Figure 8

Corneal ectasia. A, Radial keratotomy followed by laser in situ keratomileusis with resultant corneal ectasia. B, The Descemet membrane–endothelial complex seems to be intact; therefore, a deep lamellar keratoplasty was performed successfully.

Figure 9

Descemet membrane detachment. A, Persistent central bullous corneal edema of unestablished etiology 1 month after phacoemulsification. B, On high-magnification slitlamp photography, a small nasal Descemet membrane detachment was noted (arrow). C, High-speed, ultra–high-resolution optical coherence tomography (hsUHR-OCT) shows a thickened epithelium with large hyporeflective corneal epithelial bullae. D, An hsUHR-OCT image highlights the small Descemet membrane separation adjacent to the missing Descemet membrane to the right. E, A more central view of the Descemet membrane detachment with the adjacent missing Descemet membrane consistent with the overlying central area of bullous epithelium (not shown).