Contrast-Enhanced Corneal Wound Imaging by Optical

Coherence Tomography

Preeya K. Gupta, MDJustis P. Ehlers, MD

Terry Kim, MD

Duke Eye Center, Durham, NCCole Eye Institute, Cleveland, OH

Financial Disclosures: none

Background

• Modern cataract surgery has shifted from scleral incisions to clear corneal incisions (CCI) as today’s standard of care.

• While these incisions offer reduced surgical time and faster visual recovery, wound construction and integrity is critical to preventing complications, such as wound leakage and endophthalmitis.

• Cadaveric studies of CCI have suggested that ingress of fluid may occur. However, no prior study to date has examined in vivo CCI integrity.

Purpose

• To evaluate post-phacoemulsification clear corneal wound morphology and integrity using contrast-enhanced SD-OCT both immediately after surgery and 24 hours post-operatively.

Methods

• Prospective cohort study including 18 patients (n=18 eyes) undergoing unilateral routine cataract surgery

• SD-OCT imaging (Cirrus™, Carl Zeiss Meditec Inc, Dublin, CA) of the corneal wound was performed on all patients immediately following cataract surgery and on post-operative day one

• A topical contrast agent, prednisolone acetate 1% (PA), was used to help evaluate wound integrity.  OCT features of the corneal incision were analyzed, as well as changes in wound interface reflectivity after administration of topical PA.

Methods• Volume scans and five-line raster scans were performed

before and after application of PA. All scans were centered on the corneal wound.

• Main outcome measures were quantitative and qualitative description of wound morphology and contrast enhancement of the wound interface.

• Qualitative analysis of OCT features included presence of internal wound gape, external wound gape, Descemet’s membrane detachments, and contrast enhancement following PA. ImageJ software was used to analyze wound architecture.

Results• Internal wound gape was found in 89% of eyes

• Gape area decreased by 43% from day 0 to 1 (462 µ2 vs. 273µ2   p< 0.01)

Figure 1: SD-OCT image of clear corneal incision wound gape (a) post-operative day 0, (b) post-operative day 1.

(b)(a)

Results• Contrast enhancement at the wound interface was seen in 56% of

eyes on day 0 compared to 17% on day 1 following application of PA (p< 0.05)

• Contrast enhancement in uniplanar wounds (6/6, 100%) was significantly higher than in biplanar wounds (6/13, 43%, p = 0.05)

(a) (b)

*

Figure 2: Clear corneal wound interface (a) prior to application of prednisolone acetate and (b) post application of prednisolone acetate. Note increased reflectivity in the wound interface (*)

Results

• Decreased intraocular pressure correlated with increased contrast enhancement (p< 0.05)

Figure 3: (a) Clear corneal wound interface on post-operative day 0 in a patient with IOP=4. (b) Clear corneal wound interface on post-operative day 0 in a patient with IOP=29. Note the increased reflectivity in the wound interface in the patient with lower intraocular pressure and greater wound gape in patient with lower IOP.

(a) (b)

Table 1: Subject demographic and clinical characteristics

PatientEye Gender Incision

TypeCataract Grade

CDE IOP POD 0

IOP POD 1

Change in IOP

1 R M biplanar 2 5.77 19 17 -2

2 L M biplanar 3 6.58 14 25 11

3 R F biplanar 1.5 4.67 28 12 -16

4 R F biplanar 2.5 5.22 20 14 -6

5 R M biplanar 2.5 7.91 15 17 2

6 R F biplanar 1 1.89 16 19 3

7 R M biplanar 3 14.78 4 9 5

8 L F biplanar 2.5 7.67 28 25 -3

9 R F biplanar 2 7.35 6 14 8

10 R F biplanar 2.5 NA 17 22 5

11 L F biplanar 1.5 1.88 23 14 -9

12 L F biplanar 2 5.15 13 15 2

13 L F Biplanar 2 12.23 10 9 -1

14 L M Uniplanar 1.5 9.88 5 17 12

15 L M Uniplanar 1.5 15.7 29 26 -3

16 R F Uniplanar 2 10.95 12 23 11

17 R M Uniplanar 1.5 19.56 6 43 37

18 R M Uniplanar 3 32.33 10 22 12

Table 2. OCT features of all clear corneal incisions (n=18)

Wound Visible

Internal Wound Gape

Present

External Wound

Gape Present

Internal Tissue

Overhang

Descemet’s Detachment

Subepithelial Fluid

Contrast seen on Surface

Subjective appearance of contrast in the

wound

POD 0 18 (100%) 16 (89%)

4 (22%) 2 (11%) 11 (61%) 5 (28%) 18 (100%) 17 (94%)

POD 1 18 (100%) 16 (89%)

5 (28%) 2 (11%) 11 (61%) 7 (39%) 17 (94%) 13 (72%)

Table 3. OCT features varied by clear corneal incision architecture

Incision construction

Wound Visible

Internal Wound Gape

External Wound Gape

Internal Tissue

Overhang

Descemet’s Detachment

Subepithelial Fluid

Contrast seen on Surface

Subjective appearance of

contrast in the wound

Biplanar POD 0 (n=13)

13 (100%) 13 (100%) 2 (15%) 0 (0%) 6 (46%) 4 (31%) 13 (100%) 10 (77%)

UniplanarPOD 0 (n=5)

5 (100%) 3 (60%) 3 (60%) 2 (40%) 5 (100%) 3 (60%) 5 (100%) 3 (60%)

2.2mm Incision (n=14)

14 (100%) 13 (93%) 4 (29%) 1 (7%) 9 (64%) 4 (29%) 14 (100%) 11 (79%)

>2.5 mm incision(n=4)

4 (100%) 3 (75%) 1 (25%) 1 (25%) 2 (50%) 3 (75%) 4 (100%) 2 (50%)

Conclusions

• Wound morphology evolves during the early postoperative period.

• Wound gape and ingress of a topical contrast agent decrease during the first 24 hours following surgery.

• Contrast enhancement at the wound interface increases as the intraocular pressure decreases.