J Korean Ophthalmol Soc.  2014 Jan;55(1):66-72.

Comparison of Early Clinical Result of Deep Anterior Lamellar Keratoplasty Using FSlaser Versus Manual Trephine

• Kim EY
• Park JH
• Lee YE
• Joo CK

Abstract

PURPOSE
To compare outcomes of femtosecond laser-enabled deep anterior lamellar keratoplasty (IE-DALK) versus manual trephine using deep anterior lamellar keratoplasty (Manual DALK, M-DALK).
METHODS
Seventeen eyes from 17 patients underwent manual deep anterior lamellar keratoplasty, and femtosecond laser-enabled deep anterior lamellar keratoplasty was performed in 13 eyes of 13 patients. Postoperative clinical outcomes such as best corrected visual acuity, refractive astigmatism, keratometric astigmatism, endothelial cell density were compared between the two groups.
RESULTS
The mean log MAR best spectacle-corrected visual acuity (BSCVA) was 0.31 +/- 0.17, 0.23 +/- 0.15, 0.18 +/- 0.14 in the IE-DALK group, and 0.55 +/- 0.41, 0.45 +/- 0.28, 0.35 +/- 0.22 (p = 0.056, p = 0.025, p = 0.313) in the M-DALK group at postoperative 2, 4, and 6 months respectively. The mean keratometric cylinder was 5.35 +/- 1.57, 4.24 +/- 1.97, 3.65 +/- 1.31 in the IE-DALK, 8.32 +/- 2.75, 6.80 +/- 2.50, 4.54 +/- 1.25 (p = 0.031, p = 0.041, p = 0.370) in the M-DALK group at postoperative 2, 4, and 6 months respectively. Endothelial cell counts in the two groups did not differ significantly at postoperative 6 months.
CONCLUSIONS
The IE-DALK showed better results in BSCVA and keratometric astigmatism in the early postoperative period, in comparison with the M-DALK, and can be considered as a valuable method in deep anterior lamellar keratoplasty.

Keyword

Deep anterior lamellar keratoplasty; Endothelial cell density; Femtosecond laser

MeSH Terms

Astigmatism
Corneal Transplantation*
Endothelial Cells
Humans
Methods
Postoperative Period
Visual Acuity

Figure

• 

  Figure 1. Settings on the FSL to create a partial-thickness mushroom configuration in the recipient and doner cornea as-suming a minimum corneal pachymetry of 550 mm. Vertical cuts overlap 0.2 mm horizontally and 20 mm vertically with the horizontal lamellar cut at a 90-degree angulation to the corneal surface to ensure completely cut intersecting wound edges. The posterior side cut depth was calculated by subtracting 100 mm of residual cornea from the minimum corneal pachymetry (solid line, FSL cuts; dotted line, manual dissection by the sur-geon).

• 

  Figure 2. Postoperative changes of log MAR mean best-spec-tacle corrected visual acuity (BCVA) after manual trephine using deep anterior lamellar keratoplasty (M-DALK) versus IntraLase-enabled deep anterior lamellar keratoplasty (IE-DALK); Postoperative BCVA improved gradually in both groups. BCVA in IE-DALK group was better than M-DALK group postoperatively, but the differences between two groups were statistically significant at 4 months (p = 0.034). The statistical analysis was performed using Mann-Whitney U test. A p-value less than 0.05 is statistically significant.

• 

  Figure 3. The cylinder measured using autorefractor in both groups of M-DALK and IE-DALK at 2, 4 and 6 months postoperatively. The refractive cylinder showed lower value in IE-DALK during follow up periods, and the difference was statistically significant at 2 months postoperatively (p = 0.032) (A). The keratometric cylinder measured using manual keratometer showed lower value in IE-DALK than M-DALK, and the difference was statistically significant at 2 months (p = 0.031), and 4 months (p = 0.041) postoperatively (B). The statistical analysis was performed using Mann-Whitney U test. A p-value less than 0.05 is statistically significant.

• 

  Figure 4. Difference of postoperative central corneal thickness between M-DALK (535.75 ± 54.0) and IE-DALK (530.14 ±31.2) group (p = 0.865, Mann Whitney test). Pachymetry was performed at 6 months postoperatively (both group).

• 

  Figure 5. Difference of postoperative endothelial cell density between M-DALK (2361.60 ± 320.5) and IE-DALK (2559.00± 531.75) group (p = 0.880, Mann Whitney test). Specular microscopy was performed at 6 months postoperatively (both group).

• 

  Figure 6. Anterior segment photographs of the patients 2 months after surgery show the clear central cornea with well attached peripheral flange in IE-DALK (A), and mild edematous cornea with well attached graft in M-DALK (B).

• 

  Figure 7. Six months postoperatively, Visante optical coherence tomography of IE-DALK (mushroom shape) (A), demonstrating the perfect match of the recipient to the donor. In contrast, conventional M-DALK (B) may show the lack of precise match of cut between the two pieces of tissues and protrusions such as hills.

Reference

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