1. Deep Anterior Lamellar Keratoplasty (DALK) Vs Penetrating Keratoplasty (PK) in patients with Keratoconus (KC).
Dr. K.S.SIDDHARTHAN
Aravind Eye Hospital
Coimbatore
The author has no financial interest in the subject matter of this poster.

2. Introduction
Deep Anterior Lamellar Keratoplasty [DALK] has been recommended as an alternative to Penetrating keratoplasty( PK) for the treatment of keratoconus.
Corneal graft failure in PK is most frequently the result of destruction of the donor endothelium by inflammatory cells during acute or chronic allograft rejection.
Comparative studies with PK have shown overall similar visual outcomes when both techniques are used .
The main disadvantage of DALK is of being both a technically more challenging and time consuming procedure with a steep learning curve compared to PK.
In this study we report the comparison of clinical outcomes of DALK Vs PK.

3. Purpose
To compare the clinical outcomes of Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty in patients with keratoconus.
Methods
Prospective & Interventional case series. 66 eyes of 53 consecutive patients with KC who underwent DALK and PK between September to April 2009 were routinely included.
Visual and refractive outcomes at 1,3,6,12 months were analyzed. Complication rates were also analyzed.

4. Data Analysis Comparison of
Visual acuity - (Uncorrected and Best corrected) at 1 month and 1 year – Chi Square test.
Spherical equivalents - (non- normal distribution - Mann Whitney U test).
Complication rates – Compared Between DALK and PK.

5. RESULTS Visual Outcome at 1 month Uncorrected Visual acuity
p (NS)
Best corrected Visual acuity
p (NS)

6. Visual Outcome at 1 Year Uncorrected Visual acuity
p (NS)
Best corrected Visual acuity
p (NS)

7. Spherical Equivalent

8. Complications
There was no intra operative complication in PK compared to 27.3% in DALK.
Postoperative graft infection was not statistically significantly different between the two surgery types (DALK – 5.3% vs PK %) (p-0.527).
Post operative graft rejection was seen in one patient with PK.

9. Complications of DALK Suture related Graft Melt Inter phase Debris
Descemet’s Detachment
Graft Infection
Descemet’s Tear

10. Summary
Visual improvement in DALK (83% ) was better than PK (63.4%) at 1 month. However, at 1 year the visual improvement between the two procedures were comparable (92.5% in DALK and 90.9% in PK).
The average difference made in spherical equivalent at 1 year compared to preoperative period was 10.5±7.5 in DALK and 19.2±5.2 in PK. The impact on spherical equivalent by PK was statistically significantly higher (p-0.003).
Intra operative complications were more in DALK ,compared to PK.

11. Conclusions
Penetrating keratoplasty is no longer an automatic choice for the surgical treatment for keratoconus.
Best-corrected visual acuity and refractive results are similar after DALK and PK.
DALK allows earlier visual rehabilitation, use of low dose steroids for shorter duration and earlier suture removal compared to PK.
DALK is more technically challenging but allows the risk of endothelial rejection to be avoided.
DALK is a safe alternative to penetrating keratoplasty in patients with keratoconus.

12. Bibliography
Troutman RC, Lawless MA. Penetrating keratoplasty for keratoconus. Cornea 1987;6:298 –305.
Panda A, Bageshwar LM, Ray M, et al. Deep lamellar keratoplasty versus penetrating keratoplasty for corneal lesions. Cornea 1999;18:172–5.
Jun Shimazaki, Shigeto Shimmura et al .Randomized Clinical Trial of Deep Lamellar Keratoplasty Vs Penetrating Keratoplasty. Am J Ophthalmol 2002;134:159–165.
Stephanie L. Watson, FRANZCO et al .Comparison of Deep Lamellar Keratoplasty and Penetrating Keratoplasty in Patients with Keratoconus. Ophthalmology 2004;111:1676–1682