Penetrating Excimer Laser Keratoplasty with vs without the Homburg Cross-Stitch Marker in Inexperienced Surgeons

Figures & data

Figure 1 The double-running diagonal cross-stitch suture according to Hoffmann used in PKP.

Figure 2 (A and B) The front surface of the instrument with 2 markings on the long and short arm respectively for positioning the instrument on the cornea (A). The back surface of the instrument: two tiny prominences at both ends of the long arm of the instrument for marking the insertion and removal site of the suture needle after blue staining (B).⁸

Figure 3 A young surgeon’s first independent continuous cross-stitch keratoplasty in a patient using the Homburg cross-stitch marker. The two sutures are crossing almost everywhere over the interface.⁸

Table 1 Distribution of Indications (n) Between the Two Groups. The Differences Between the Indications Were Not Statistically Significant Between the 2 Groups (P = 0.24)

Indications	Group 1 (without Device) n	Group 2 (with Device) n	Percent
Keratoconus	24	37	47%
Scars after keratitis	17	10	21%
Fuchs dystrophy	10	7	13%
Posttraumatic/postsurgical	10	8	14%
Corneal dystrophy	4	3	5%
Total	65	65	100%

Table 2 Corrected Distance Visual Acuity (CDVA) (Mean ± Standard Deviation) (Min–Max) in the Two Groups at the Different Follow-Up Time Points After PKP. In Group 2 (with Device), The CDVA Was Significantly Better (P = 0.04, with Bonferroni Correction) Compared to Group 1 (without Device) at 6 Weeks, 10 Months Post Operative and 6 Weeks After the Second Suture Removal

	Group 1 (without Device)	Group 2 (with Device)	P-value
Preoperative	1.11 ± 0.74	1.12 ± 0.69	0.69
	(0.30–2.30)	(0.22–2.30)
6 weeks post OP	0.64 ± 0.27	0.44 ± 0.27	0.04
	(0.22–1.30)	(0.00–1.00)
10 months post OP	0.57 ± 0.40	0.32 ± 0.23	0.04
	(0.00–1.30)	(0.00–1.00)
6 weeks after 1st suture removal	0.55 ± 0.42	0.31 ± 0.20	0.12
	(0.10–2.00)	(0.00–1.00)
6 weeks after 2nd suture removal	0.49 ± 0.44	0.29 ± 0.22	0.04
	(0.00–2.00)	(0.00–1.00)

Figure 4 Corrected distance visual acuity (CDVA) (logMAR). There was a statistically significant better visual acuity at 6 weeks, 10 months post operative and 6 weeks after the second suture removal in group 2 (with device) compared to group 1 (without device).

Table 3 Topographic Astigmatism (Mean ± Standard Deviation) (Min–Max) in the Two Groups at Different Time Points After PKP. In Group 2 (with Device), Topographic Astigmatism Was Significantly Lower (P < 0.03 with Bonferroni Correction) at 6 Weeks, 10 Months Post Operative and 6 Weeks After the First Suture Removal Compared to Group 1 (without Device)

	Group 1 (without Device)	Group 2 (with Device)	P-value
6 weeks post OP	6.95 ± 3.85	4.50 ± 3.65	0.002
	(0.7–20.0)	(0.3–16.0)
10 months post OP	5.50 ± 3.57	3.62 ± 2.27	0.004
	(0.7–18.0)	(0.2–11.9)
6 weeks after 1st suture removal	5.45 ± 3.01	3.03 ± 2.45	0.03
	(1.0–17.0)	(0.9–13.0)
6 weeks after 2nd suture removal	5.32 ± 3.94	3.72 ± 1.94	0.08
	(0.9–16.0)	(0.1–8.0)

Figure 5 Topographic astigmatism. There was a statistically significant lower topographic astigmatism at 6 weeks, 10 months post operative and 6 weeks after the first suture removal in group 2 (with device) compared to group 1 (without device).

Table 4 Refractive Cylinder (Mean ± Standard Deviation) (Min–Max) in the Two Groups at Different Time Points After PKP. In Group 2 (with Device), The Refractive Cylinder Was Significantly Lower (P = 0.002 with Bonferroni Correction) at 6 Weeks Postoperative Time Point Compared with Group 1 (without Device)

	Group 1 (without Device)	Group 2 (with Device)	P-value
6 weeks post OP	6.13 ± 3.34	3.78 ± 2.64	0.002
	(0.75–13.0)	(0.75–11.0)
10 months post OP	4.74 ± 2.62	3.80 ± 2.40	0.16
	(0.75–11.0)	(0.25–9.5)
6 weeks after 1st suture removal	5.12 ± 2.82	4.06 ± 2.48	0.16
	(1.0–11.25)	(0.50–13.0)
6 weeks after 2nd suture removal	4.84 ± 3.21	3.51 ± 1.88	0.12
	(0.25–12.5)	(0.25–8.0)

Figure 6 Refractive cylinder. There was a statistically significant lower cylinder value at 6 weeks post operative time point in group 2 (with device) compared to group 1 (without device).

Suffo S, Seitz B, Daas L. The homburg cross-stitch marker for double-running sutures in penetrating keratoplasty. Klin Monatsbl Augenheilkd. 2020;1055:1275–1807.

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