11-0 mersilene as running suture for penetrating keratoplasty

Update on Suture Techniques in Corneal Transplantation: A Systematic Review

Effective suturing remains key to achieving successful outcomes in corneal surgery, especially anterior lamellar keratoplasty and full thickness transplantation. Limitations in the technique may result in complications such as wound leak, infection, or high astigmatism post corneal graft. By using a systematic approach, this study reviews articles and conducts content analysis based on update 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria). The aim of this paper is to summarize the state of the art of corneal suturing techniques for every type of corneal transplant and patient age and also their outcomes regarding astigmatism and complications. Future developments for corneal transplantation will be also discussed. This is important because especially the young surgeon must have knowledge of the implications of every suture performed in order to achieve consistent and predictable post-operative outcomes and also be aware of all the possible complications.

Post-penetrating keratoplasty astigmatism

Postoperative astigmatism is one of the common complications affecting visual outcomes after a penetrating keratoplasty. It can result from various factors related to host, donor and surgical technique, resulting in suboptimal visual outcome. While some of the measures taken during preoperative planning and during actual surgery can reduce the magnitude of postoperative astigmatism, postoperative correction of astigmatism is often required in cases with high degrees of astigmatism. When spectacles and contact lenses fail to provide optimal visual outcomes, various surgical techniques that include astigmatic keratotomy, compression sutures, toric intraocular lens placement, and laser refractive procedures can be considered. When none of these techniques are able to achieve a desired result with in the acceptable optical range, a repeat keratoplasty is considered a last option. We discuss the various causes and management of complication of postoperative astigmatism occurring after a full thickness corneal transplantation surgery.

Comparison of complication rates and postoperative astigmatism between nylon and mersilene sutures for corneal transplants in patients with Fuchs endothelial dystrophy

PURPOSE

The purpose of this study is to evaluate corneal astigmatism and suture-related complications for transplants sutured with nylon and transplants sutured with Mersilene in primary corneal transplants for Fuchs endothelial dystrophy.

METHODS

A retrospective, observational, and comparative study between transplants sutured with either nylon 10-0 or 11-0 (n = 108) or Mersilene 11-0 (n = 58) was done. One hundred sixty-six eyes of 140 patients who received a primary penetrating keratoplasty for Fuchs endothelial dystrophy between 1995 and 2001 at the Rotterdam Eye Hospital in Netherlands were included.

RESULTS

Overall, transplant survival did not differ between groups (log-rank test; P = 0.24). During the first 2 years after transplantation, significantly lower astigmatism was seen in transplants sutured with nylon (P = 0.03). Transplants sutured with Mersilene had a significantly higher risk of surgical intervention to correct astigmatism or wound dehiscence after transplantation (hazard ratio, 2.83; 95% confidence interval, 1.34-6.01). Time to first infiltrate, metaplasia (marked scarring along the sutures), or cheesewiring was significantly less in the Mersilene group (P < 0.01). There was a tendency toward a higher risk of complications associated with loose or broken sutures in the nylon group (hazard ratio, 2.00; 95% confidence interval, 0.57-6.98), which was more pronounced after 2 years.

CONCLUSIONS

During the first years after corneal transplant surgery, Mersilene sutures are associated with a higher risk of complications and more interventions to correct suture-related problems. However, after 2 years, the grafts seem to be able to retain Mersilene sutures with less risk of suture-related complications as compared with grafts with retained nylon sutures. These favorable long-term effects of Mersilene sutures may outweigh its short-term disadvantage in patients with Fuchs endothelial dystrophy.

Astigmatism After Mersilene and Nylon Suture Use for Penetrating Keratoplasty

PURPOSE

To evaluate postoperative astigmatism after the use of Mersilene and nylon sutures for penetrating keratoplasty.

METHODS

Two groups of 12 patients each (age, 20-50 years) suffering from keratoconus underwent penetrating keratoplasty. Continuous suturing combined with 12 interrupted sutures was used in each case: Mersilene 11-0 sutures were used in group 1, whereas nylon 10-0 sutures were used in group 2. Sutures were removed to control astigmatism when required. All patients were monitored for 36 months.

RESULTS

During the follow-up period, sutures were removed in each eye as indicated by astigmatism or breakage. In group 1 (Mersilene 11-0 sutures), no breakage of sutures was recorded. In group 2 (nylon 10-0 sutures), breakage of sutures was recorded in 11 of 12 cases. However, continuous sutures were removed in 2 patients in group 2. After the first year, the astigmatism remained within +/-1.00 diopter in all except 1 patient in group 1 and in 5 patients in group 2. No suture-related complications were recorded except for scarring with photophobia in 1 patient in group 1 and suture breakage in 11 eyes in group 2.

CONCLUSION

Mersilene sutures can provide a stable postoperative astigmatism, whereas nylon sutures have a tendency to break and cause changes in corneal astigmatism.

Shortterm and longterm visual and astigmatic results of an opposing 10-0 nylon double running suture technique for penetrating keratoplasty

BACKGROUND

In ophthalmic surgery, corneal transplantation (penetrating keratoplasty) may be employed when the clarity of the cornea has been significantly compromised by conditions such as scarring, edema, and variable corneal thickness. Irregularities in corneal curvature can occur postoperatively. This astigmatism is of concern, because it can impair visual acuity despite an otherwise good surgical result. Different suturing techniques have been developed to minimize astigmatism. The purpose of this study was to evaluate an opposing 10-0 nylon double running suture technique for penetrating keratoplasty.

STUDY DESIGN

A retrospective study was undertaken of 91 records of patients who underwent penetrating keratoplasty performed by one surgeon (RNG). This represents 54.8% of 166 consecutive cases. Every eye with an opposing double running suture and a 1- to 3-month postsuture removal followup was selected and evaluated for best corrected visual acuity and astigmatism, excluding eyes that developed graft failure or corneal ulcer or that had lack of adequate followup. The cases were divided into five groups by preoperative diagnosis: pseudophakic bullous keratopathy (n = 43), aphakic bullous keratopathy (n = 5), keratoconus (n = 17), Fuchs dystrophy (n = 12), and miscellaneous (n = 14). The mean standard followup period was 13.7 months after penetrating keratoplasty. Thirty percent of the eyes had an extensive followup, with a mean of 33 months after penetrating keratoplasty.

RESULTS

Eighty-two percent of the patients had a significant improvement of their visual acuity postoperatively, defined by a five-line improvement of best corrected visual acuity or a best corrected visual acuity of 20/40 or better. The mean astigmatic keratometric reading was 3.98 diopters, with a manifest refraction cylinder of 3.42 diopters at the 1- to 3-month postsuture removal visit. This study also shows that there is no statistically significant change in keratometric astigmatism or manifest refraction cylinder from the 1- to 3-month postsuture removal measurements to the more extensive followup of 18 to 66 months after penetrating keratoplasty (p > 0.10).

CONCLUSIONS

This suture technique allows for excellent longterm stability of the wound with visual and astigmatic results that are comparable to those of previous studies. The use of the opposing double running suture is a viable alternative to some of the other widely used techniques and may be considered more stable and secure.

11-0 Mersilene alone as a single running suture in corneal grafts

PURPOSE

To study the safety and long-term stability of 11-0 Mersilene when used alone as a single running suture in corneal grafts.

METHODS

Seventeen eyes on which corneal transplants were performed with 11-0 Mersilene alone as a single running suture between October 1992 and April 1998 were entered into this study. Post-operative data were collected retrospectively on a standardised form. Mean age of patients at the time of surgery was 49.7 years. Pre-operative diagnoses were keratoconus (8 eyes), Fuchs' corneal dystrophy (6 eyes), megalocornea (1 eye), bullous keratopathy (1 eye) and irregular astigmatism following penetrating corneal injury (1 eye). Mean follow-up was 54.1 months, and ranged between 24 and 91 months.

RESULTS

Fourteen eyes (82%) achieved visual acuities of 6/18 or better. Post-keratoplasty astigmatism was < or = 5D in 14 eyes (82%). Sutures were left intact in 9 eyes for a mean period of 51.1 months (24-91 months). Complications included wound leak (3 cases), elevated edge (1 case), high intraocular pressure (1 case), sterile infiltrates (1 case) and early rejection (1 case).

CONCLUSION

11-0 Mersilene alone can be effectively used as a single running suture in corneal grafts. These sutures can safely be left intact for a long period due to Mersilene's non-biodegradable nature.

Comparison of suture-in and suture-out postkeratoplasty astigmatism with single running suture or combined running and interrupted sutures

PURPOSE

To evaluate postkeratoplasty astigmatism between two suture techniques 2 to 4 years postoperatively in a group of patients previously studied 9 months postoperatively.

METHODS

Thirty-two patients who underwent penetrating keratoplasty were randomly assigned to one of two groups. Group 1 (16 patients) had a 24-bite single running 10-0 nylon suture with postoperative suture tension adjustment; group 2 (16 patients) had combined 16-bite running and eight interrupted 10-0 nylon sutures with selective postoperative removal of interrupted sutures. During long-term follow-up, the running suture was removed in 19 patients (59%).

RESULTS

Postoperative astigmatism was slightly lower in patients with the single running suture technique when sutures were in place and was slightly greater after the sutures were removed compared with the combined running and interrupted suture technique (sutures in: single running suture +/- SD, 2.6 +/- 1.2 diopters [five patients, 31%]; combined running and interrupted sutures, 3.8 +/- 1.1 diopters [eight patients, 50%]; sutures out: single running suture, 3.3 +/- 1.3 diopters [11 patients, 69%]; combined running and interrupted sutures, 2.8 +/- 1.5 diopters [eight patients, 50%]). These differences were not statistically significant (sutures in, P < .13; sutures out, P < .46). Averages of follow-up were group 1,48.3 +/- 10.6 months and group 2, 46.3 +/- 13.0 months. Follow-up ranged from 23 to 60 months.

CONCLUSIONS

Postoperative astigmatism 4 years after penetrating keratoplasty is similar for these two suturing techniques, with or without residual sutures. A single running suture results in more rapid visual rehabilitation and less early astigmatism compared with the combined interrupted and running suture technique.

Suture adjustment in penetrating keratoplasty

Postoperative adjustment of a single running penetrating corneal graft suture was done in 19 patients (22 adjustments). The short-term effect of this procedure was a mean reduction of corneal astigmatism of 4.39D (p < 0.0001). Thereafter, the corneal contour was fairly stable, provided that the running suture remained intact and tight. Localized loosening of the graft suture significantly increased the corneal astigmatism. Following removal of the graft suture no statistically significant mean change of corneal astigmatism was found. However, patients with a previously intact running suture tended to show increased astigmatism, while those with a previous localized suture loosening usually showed a decreased astigmatism after suture removal. The main benefit of suture adjustment is apparently the rapid and fairly stable reduction of postkeratoplasty astigmatism usually obtained, but unfortunately this effect seems chiefly to exist only as long as the graft suture remains intact and tight.