Ординатура / Офтальмология / Английские материалы / Corneal Endothelial Transplant (DSAEK, DMEK & DLEK)_John_2010

Figure 18-11: Straight needle with Prolene suture is passed vertically under the inferior scleral flap.

Figure 18-12: A 27-gauge needle is bent vertically.

13.The 27-gauge needle is then withdrawn, while guiding the straight 10-0 Prolene needle to exit under the superior flap, traversing the posterior chamber (Figure 18-16).

14.The Prolene suture is then pulled through the initial superior limbal incision using a Sinskey hook (Katena) and this suture is cut in the middle using microscissors (Figures 18-17 and 18-18).

15.The lower end of the Prolene suture is tied around the lower haptic of the PC IOL (AMO Duralens PS26TB, 1-piece polymethylmethacrylate, 7.0 mm optic and 14.0 mm overall diameter, Allergan Medical Optics,

Figure 18-13: The 27-gauge needle is passed under the superior scleral flap.

Figure 18-14: The straight needle directed tangentially to meet the superior one.

Irvine, CA) and the upper end of the suture is tied around the superior haptic (Figure 18-19).

Surgical tip: The tied suture knot, should be at the greatest haptic spread. In addition, the one-piece structure of the IOL provides torsional rigidity and stabilization for two-point fixation.

16.The IOL then is introduced through the original superior limbal incision into the anterior chamber and guided to the posterior chamber (Figures 18-20 and 18-21).

Surgical tip: While introducing the IOL, the external lower Prolene suture should be pulled out slowly by the surgical assistant to avoid looping the suture around the IOL.

Figure 18-15: The straight needle fed into the lumen of the 27 gauge needle.

Figure 18-16: The 27 gauge needle is being withdrawn.

Figure 18-18: The Prolene suture (arrow) is pulled out using a Sinskey hook.

Figure 18-19: One piece polymethylmethacrylate PC IOL.

Figure 18-17: The Prolene suture (arrow) traversing the posterior chamber.

Figure 18-20: The IOL is introduced and the lower suture is pulled out simultaneously.

Figure 18-21: The IOL optic is in position.

Figure 18-22: The superior haptic is being placed into the posterior chamber and into the ciliary sulcus.

17.The upper haptic is then placed in position and the superior suture is pulled out at the same time (Figure 18-22).

18.Final positioning of the PC IOL is done by pulling the two ends of the Prolene sutures tight (Figure 18-23) and then tying it to itself by passing the needle, after being bent vertically at the end, through the sclera, under the flap (Figures 18-24 and 18-25). This is done at the inferior (Figures 18-26 and 18-27) and the superior positions (Figures 18-28 and 18-29) followed by suturing of the flaps with 10-0 nylon sutures (Figure 18-30). This results in positioning the superior and inferior haptics of the PC IOL into the ciliary sulcus and the PC IOL is thus held in place by the 10-0 Prolene sutures (2-point fixation). The conjunctiva then is

Figure 18-23: The two sutures are pulled up to check lens position.

Figure 18-24: The lower end of each needle is bent vertically by needle holder.

closed either by cautery or using 10-0 vicryl interrupted sutures.

19.The anterior chamber then is irrigated with a twoway canula (Simco canula, Model No. K7-4300, Katena) to remove the viscoelastic substance from the anterior chamber. The anterior chamber is then filled with filtered air.

20.The donor cornea is then mounted within the artificial anterior chamber (Bausch & Lomb) (Figure 18-31)

(See also Chapter 12, Artificial Anterior Chambers). A 9.0 mm diameter disposable suction trephine (Barron radial vacuum trephine, Katena) is applied to the surface of the donor cornea and suction is engaged

Figure 18-25: The bent needle is seen.

Figure 18-26: The lower needle is passed through the sclera under the inferior flap.

Figure 18-28: The upper needle is passed under the superior sclera flap.

Figure 18-29: The knot is tied under the superior sclera flap.

Figure 18-27: The knot is tied under the flap.

Figure 18-30: The lens is in position and the scleral flaps covering the knots are seen.

Figure 18-31: The donor cornea is mounted within the artificial anterior chamber.

Figure 18-32: A 9.0 mm Barron trephine is positioned over the donor cornea.

(Figure 18-32). Trephination is carried out to approximately 60 to 75% of the corneal thickness. Surgical tip: This depth is achieved at eight quarter turns of the trephine wheel. The trephine is set at three quarter turns back after leveling with the suction barrel before applying the trephine to the donor cornea.

21.A lamellar dissection of the 9.0 mm partially trephined cornea is then performed with a crescent blade (Figure 18-33) until the lower end (Figure 18-34), leaving a small hinge. The lamellar cap is returned into position (Figure 18-35) to protect the posterior lamella during the use of the punch.

22.The donor cornea is then removed from the artificial anterior chamber (Figure 18-36) and mounted onto a 7.5 mm donor punch block (Barron vacuum donor corneal punch, Katena) with the endothelial side up

(Figure 18-37) and trephined (Figure 18-38).

Figure 18-33: Lamellar dissection of the partially trephined donor cornea with a crescent blade is carried out.

Figure 18-34: End of dissection of 9.0 mm partially trephined cornea.

Figure 18-35: The dissected lamellar cap is placed back into position.

Figure 18-36: The donor cornea is removed from the artificial anterior chamber.

Figure 18-37: The cornea is placed in a 7.5 mm punch block.

Figure 18-39: The donor lamellar disk is placed on the Ousley spatula with the endothelial side down.

23.The donor disk, which is comprised of the endothelium along with its attached deep corneal stroma, is separated from the anterior donor button and it is placed endothelial side down onto the Ousley spatula (Bauch & Lomb) coated with sodium hyaluronate

(Figure 18-39).

Surgical tip: A very fine film of viscoelastic substance (Healon 5) is spread over the spatula to protect the endothelium. Excessive viscoelastic material on the Ousley spatula can dislodge the disk from the host corneal stroma, because the viscoelastic material might enter the interface and prevent optimal adherence between the donor and host corneal stroma.

Figure 18-38: The donor cornea is punched with a 7.5 mm Barron trephine.

Figure 18-40: The lamellar disk is in position within the recipient anterior chamber with the donor disk approximated to the recipient cornea using the Ousley spatula.

Figure 18-42: The donor corneal graft is in position with an air bubble in the recipient anterior chamber.

24.The lamellar disk then is introduced by the Ousley spatula through the initial superior limbal incision and pressed gently upward (Figure 18-40) for the tissue to adhere to the recipient corneal lamella. The spatula is then guided out of the wound. Additional air is injected into the anterior chamber through the paracentesis port to stabilize the donor disk.

25.The superior limbal wound is closed with interrupted 10-0 nylon sutures (Figures 18-41 and 18-42).

26.The lamellar donor disk graft is positioned properly by the use of a Sinskey hook introduced through the wound and into the interface.

Surgical tip: Any small air bubbles at the interface should be squeezed out, because they can interrupt the graft adhesion.

C

Figures 18-43A to C: Preoperative and postoperative slit-lamp photographs. (A) Preoperative photograph showing severe aphakic bullous keratopathy with hand motion vision. (B) One week postoperatively with partial clearing of the corneal edema and a scleralfixated PC IOL in position. (C) Six months postoperatively with a clear cornea and a vision of 20/40.

A

B

C

Figures 18-44A to C: Preoperative and postoperative photographs of another case. (A) Severe aphakic bullous keratopathy and hand motion vision. (B) One month postoperatively with a clear cornea and a vision of 20/100. (C) One year postoperative with a clear cornea, 20/60 vision, and well-positioned scleral-fixated PC IOL.

27.A collagen shield soaked in dexamethasone and levofloxacin is placed over the cornea and patched. The patient then remains in the supine positioned for 2 hours in the recovery room [See also Section 8, Deep Lamellar Endothelial Keratoplasty (DLEK)].

Postoperative Management

The position of the graft is evaluated every 4 hours postoperatively (Editorial Note: The timing of postoperative evaluations depend on the surgeon’s preference). Graft repositioning should be attempted as early as possible if the disk is dislodged. Topical prednisolone eye drops are given hourly during the first postoperative day with decreasing frequency according to the surgical inflammatory response [See also Section 9, Deep Lamellar Endothelial Keratoplasty (DLEK)]. Antibiotic drops also are administered four times daily for 2 weeks.

The patient undergoes a follow-up examination on day 1, week 1, every month for 3 months, and then every 3 months. Examples of cases with severe aphakic bullous keratopathy preand postoperatively are shown in Figures 18-43 and 18-44.

DLEK provides an adequate treatment for endothelial decompensation. This procedure facilitates obtaining a smooth corneal surface and for the most part maintains the patient’s own preoperative corneal topography and the degree of astigmatism. The combination of anterior vitrectomy and scleral-fixated PC IOL implantation performed through the same incision used for DLEK makes it a combined surgical approach in cases of aphakic or pseudophakic bullous keratopathy.

References

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