1. Eric Dai MD, Pawan Prasher MD, James McCulley MD, R. Wayne Bowman MD.
Corneal Densitometry Measurement After Deep Anterior Lamellar Keratoplasty by Oculus Pentacam
Eric Dai MD, Pawan Prasher MD, James McCulley MD, R. Wayne Bowman MD.
The University of Texas Southwestern Medical Center, Dallas, TX.

2. Commercial Support Disclosure
The authors do not have any financial arrangements or affiliations regarding the products and technology used in this study.

3. Purpose
To correlate changes in corneal densitometry values from Oculus Pentacam with clinical slit lamp examination after deep anterior lamellar keratoplasty (DALK).

4. Methods
Pentacam images and slit lamp photographs were performed in nine eyes of nine patients at various intervals during the postoperative course after DALK.
Nine eyes of nine patients with no prior corneal surgery served as controls.
The values for peak anterior stromal density and posterior stromal density at the level of the graft interface along the 180 degree axis were chosen for analysis.
These values were subsequently correlated with clinical grading of interface haze using previously published guidelines1.

5. Clinical Grading of Interface Haze1
Grade 0 for a completely clear cornea
Grade 0.5 for trace haze seen with careful oblique illumination with slit-lamp biomicroscopy
Grade 1 for more prominent haze not interfering with visibility of fine iris details
Grade 2 for mild obscuration of iris details
Grade 3 for moderate obscuration of the iris and lens
Grade 4 for completely opacification of the stroma

6. Results – Control Group Pentacam Values
Patient Number
Anterior Corneal
Densitometry Value
Posterior Corneal 1
31.4
23.4 2
24.3
21.2 3 26
20.2 4
25.3 18 5
24.5
19.5 6
30.7
18.2 7
29.4 20 8
25.4
19.8 9
24.8
18.1

7. Results – Study Population
Patient No.
Age
Operated
Eye
Duration
from
surgery to
Pentacam
Exam
(days)
Anterior
Corneal
Densitometry
Value
Posterior
Slit Lamp
Interface
Haze
Grade 1 39 OD
146
35.7
42.7 3 2 41 OS
117
52.9
27.6
0.5 33 87
39.2
23.6 4 20
253
38.3
69.2 5 25
143
40.8
66.3 6 40 13
68.7
34.1 7 64 34
58.5
45.7 8 28
216
34.5
27.1 9 76
57.8

8. Results Study Group Mean Standard Deviation
Average Post Op Duration (Days)
121 79
Average Anterior Densitometry 47 12
Anterior Densitometry Range
34.5 to 68.7
Average Posterior Densitometry 41 17
Posterior Densitometry Range
23.6 to 69.2
Control Group
Mean
Standard
Deviation
Average Anterior Densitometry 27 3
Anterior Densitometry Range
24.3 to 31.4
Average Posterior Densitometry 20 2
Posterior Densitometry Range
18 to 23.4

9. Results
On slit lamp examination, interface haze varied from grade 0.5 to 3 in the study group.
Both anterior and posterior stromal densitometry values in the DALK patients were significantly greater than in the control group (p<0.01).

10. Patient No. 2 – Grade 0.5 Haze

11. Patient No. 2 – Grade 0.5 Haze

12. Patient No. 9– Grade 2 Haze

13. Patient No. 9– Grade 2 Haze

14. Patient No. 1 – Grade 3 Haze

15. Patient No. 1 – Grade 3 Haze

16. Conclusion
Corneal densitometry values obtained by the Oculus Pentacam were signifcantly higher in patients with interface haze after DALK.
Corneal densitometry appears to correlate with subjective assessment of corneal interface haze by clinical slit lamp examination in patients undergoing DALK.
The Pentacam may be a useful tool to quantify interface haze in the post operative course of DALK.
Additional study in a larger patient population is needed to further evaluate the utility of the Pentacam in grading interface haze.

17. References
Fantes FE, et. al. Wound healing after excimer laser keratomileusis (photorefractive keratectomy) in monkeys. Arch Ophthalmol May;108(5):