Dr. K.S.SIDDHARTHANAravind Eye Hospital

Coimbatore

The author has no financial interest in the subject matter of this poster.

INTRODUCTION Deep Anterior Lamellar Keratoplasty( DALK ) is increasingly performed for surgical

correction of corneal diseases that do not involve the Descemet’s membrane (DM). The surgery aims to remove the anterior layers of the cornea as close to the Descemet’s membrane (BM) as possible creating a smooth recipient bed for the donor tissue. Several different techniques have been used to facilitate this lamellar dissection .

The advantage of this technique includes the preservation of the patient’s own endothelium thus reducing the risk of immunologic reactions and graft failure and also avoids the risks involved in the postoperative long term usage of steroid medication.

In our series of DALK patients we analyzed the preoperative and postoperative visual and refractive outcomes and the complication rates . We also compared these results between the big bubble techique (BB) and manual technique (MT).

PURPOSE To report clinical outcomes of Deep anterior lamellar Keratoplasty in

patients with keratoconus(KC).

METHODS

Prospective & Interventional case series. 55 eyes of 53 consecutive patients with KC who underwent DALK between September 2003 to April 2009 were routinely included.

Visual and refractive outcomes at 1,3,6,12 months were analyzed. Complication rates were also analyzed. Big bubble technique (BB) and manual layer by layer technique (MT) were also compared.

Data Analysis Description of Visual outcomes, Spherical equivalents and complication

rates.

Comparison ofVisual 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 between BB technique and MT.

RESULTS :Visual Outcome of DALK

15.25.8

82.7

32.7

92.347.0

25.0

15.4

23.1

7.7

4.5

21.2

26.9

21.2

92.4

16.7

42.3

1.9

23.1

% o

f Eye

s

<6/60

6/60

6/24 - 6/36

6/18 or better

UCVA BCVA UCVA BCVA UCVA BCVAPresenting 1 Month 1 Year

Outcome of DALK Spherical Equivalent

Uncorrected Visual acuity p-0.203 (NS)

Visual Outcome at 1 month by method

Best corrected Visual acuity p-0.597 (NS)

Uncorrected Visual acuity p-0.134 (NS)

Visual Outcome at 1 Year by method

Best corrected Visual acuity p-0.431 (NS)

Complication rates

Overall, Intra operative complication rate was 27.8%.

There was no statistically significant difference (p-0.362) in intra operative complication between BB (20.0%) and MT (34.5%).

Micro perforations occurred in 27.3% of eyes. Postoperative Descemet’s detachments occurred in 12.7% of eyes

Postoperative graft infection (5.6%) was also not statistically significantly different between the two methods (BB-4.0% Vs MT-6.9%) (p-0.557).

Summary 82.7 % of eyes achieved BCVA of 6/18 or better within 1 month and 92.3%

of eyes achieved BCVA of 6/18 or better at 1 year.

BCVA of 6/18 or better was achieved in 87% and 79.3% of eyes at 1 month and 95.8% and 85.7% eyes at 1 year for BB technique and MT respectively.

BCVA of 6/6 vision was achieved in 11 (45.8%) eyes (BB technique)and 8 (28.6%) eyes (MT).

At one month the median spherical equivalent was -1.9 D (-14 to 6.0 ).The change in spherical equivalent was statistically significant (p<0.001). The magnitude of change was -10.1 D (-28.5 to 7.5).The median spherical equivalent was -0.25D (-10.2 to 4.8) at one year and was not statistically significant.

ConclusionsDALK has proven to be a valuable technique as an alternative to

Penetrating Keratoplasty in patients with keratoconus.

It is essentially an extra ocular procedure that helps us to avoid the chances of endothelial graft rejection by preserving the healthy recipient endothelium.

DALK allows earlier visual rehabilitation compared to PK .

Visual outcome with BB technique was better than MT, as it ensures a maximum possible depth dissection achieving a complete baring of DM so that no stromal tissue is left to cause interface haze .

BibliographyAnwar M, Teichmann KD. Big-bubble technique to bare Descemet’s

membrane in anterior lamellar keratoplasty. J Cataract Refract Surg 2002;28:398 – 403.

Sugita J, Kondo J. Deep lamellar keratoplasty with complete removal of pathological stroma for vision improvement. Br J Ophthalmol 1997;81:184–8.

Fogla R, Padmanabham P. Results of deep lamellar keratoplasty using the big-bubble technique in patients with keratoconus. Am J Ophthalmol 2006;141:254 –259.

Bruce.A.Noble, Ashish Agarwal et al. DALK –Visual Outcome and Complications for a Heterogenous Group of Corneal pathologies . Cornea 2007;26: 59-64.