Some mechanical properties of 10/0 monofilament nylon sutures

A simplified sclerocorneal tunnel approach in performing pediatric cataract surgery

BACKGROUND/AIMS

Performing pediatric lensectomy, anterior vitrectomy with intraocular lens implantation in one session, using a long sclerocorneal tunnel and covering the incision site with 8/0 Vicryl sutures.

MATERIALS AND METHODS

This study includes 52 eyes of 30 patients with pediatric cataracts. At the temporal side, the conjunctival peritomy was performed, followed by two long sclerocorneal side ports and the main incision for intraocular lens (IOLs) implantation. At the end of the operation, the side port and the conjunctiva incisions were sutured with 8/0 Vicryl sutures. The IOLs were implanted in children older than 24 months, not in smaller ones. The operations and intraoperative complications were recorded. After the operation, the patients were examined on the 1st postoperative day, then six times for the first 6 months. During follow-ups, the impact of the suture on the anterior segment complications and astigmatism was evaluated.

RESULTS

The age of the patients ranged between 2 months and 8 years. The average operation time was 28 ± 6 min. Due to the suture-related complication, neither re-suturing nor stitch removal was carried out; therefore, general anesthesia was not repeated. The average astigmatism value of the children in the postoperative 1st week was 1.5 ± 1.2 D (0.5-4.0). The mean astigmatism value was 0.8 ± 0.5 D (0.5-1.5) in the 3rd postoperative month.

CONCLUSION

The long corneoscleral tunnel method has been found safe in pediatric cataract surgery.

Treatment of Mechanical Corneal Wounds Emergencies during the COVID-19 Pandemic: Absorbable 10-0 Vicryl (Polyglactin 910) Sutures as a Suitable Strategy

Background—The COVID-19 pandemic has changed our standard practices: operating rooms were only available for functional emergencies and outpatient visits were drastically reduced in favor of telemedicine. Aim: To report the personalized “one-shot” surgery using absorbable 10-0 Vicryl (V10-0) or polyglactin 910 monofilament in mechanical corneal injuries from February 2020 to December 2021. Methods—Prospective case series with at least 12-months’ follow-up, in a French university hospital. Among the overall population of open or closed-globe emergencies (n = 40), non-penetrating corneal lamellar lacerations (long axis > 2 mm) in zone 1 (OTC group) were treated with V10-0 suture(s) (n = 10), replacing traditional non-absorbable 10-0 nylon suture(s) or medical options in first line. The outpatient visits were performed on day (D)10, month (M)2, M6 then every six months. One interim visit by phone teleconsultation was scheduled between D10 and M2, and other(s) as needed. The main outcome was best-corrected visual acuity (BCVA) at M6. Secondary outcomes included mainly corneal astigmatism (CA) at M6 complications. Results—Among the ten corneal wounds, there were three children (30%), eight domestic accidents (80%), three eyes with metallic foreign bodies (30%), four open-globe injuries (40%), and nine eyes that received high-speed projectiles or sharp objects (90%). The complete V10-0 suture(s) absorption occurred in all eyes between D10 and M2. At M6, mean far and near BCVA decreased from 0.680 ± 0.753 and 0.490 ± 0.338 preoperatively to 0.050 ± 0.071 and 0.220 ± 0.063 logMAR (p = 0.019 and p = 0.025 respectively), mean CA decreased from 4.82 ± 3.86 preoperatively to 1.15 ± 0.66 diopters (p = 0.008). BCVA and CA were unchanged thereafter. No serious adverse event nor repeated surgery occurred. The mean number of teleconsultations was 1.20 ± 0.63 without an additional nonscheduled outpatient visit. Conclusions—The absorbable V10-0 sutures might be a safe and effective alternative for eligible corneal wounds, while reducing the number of outpatient visits, especially for children (no suture removal). The COVID-19 pandemic highlighted that they are ideally suited to logistical challenges.

Thae use of microfluic spinning fiber as an ophthalmology suture showing the good anastomotic strength control

Adjusting the mechanical strength of a biomaterial to suit its intended application is very important for realizing beneficial outcomes. Microfluidic spinning fiber have been attracting attention recently due to their various advantages, but their mechanical strength has unfortunately not been a subject of concentrated research, and this lack of research has severely limited their applications. In the current work, we showed the mechanical properties of microfibers can be tuned easily and provided a mathematical explanation for how the microfluidic spinning method intrinsically controls the mechanical properties of a microfluidic spinning fiber. But we were also able to adjust the mechanical properties of such fibers in various other ways, including by using biomolecules to coat the fiber or mixing the biomolecules with the primary component of the fiber and by using a customized twisting machine to change the number of single microfiber strands forming the fiber. We used the bundle fiber as an ophthalmology suture that resulted in a porcine eye with a smoother post-operative surface than did a nylon suture. The results showed the possibility that the proposed method can solve current problems of the microfibers in practical applications, and can thus extend the range of applications of these microfibers.

Globe Rupture Following Penetrating Keratoplasty

PURPOSE

Traumatic globe rupture following penetrating keratoplasty is a life-long postoperative concern. We look at a series of penetrating keratoplasties in one institution and determine the rates of traumatic rupture and the outcomes following rupture. The reasons for persisting wound weakness are reviewed, and recommendations for eye protection based on wound strength are given.

METHODS

A case-control study compared the postsurgical rupture rates for all cases of penetrating keratoplasty to those cases of globe rupture after extracapsular cataract surgery and phacoemulsification. A literature review of corneal wound healing was completed.

RESULTS

Over 10 years 139 penetrating keratoplasties were performed. The incidence of traumatic rupture following keratoplasty was 5.8%. Fifty percent of those with ruptured globes had a visual outcome of hand movement vision or worse. Of the traumatic ruptures, 37.5% occurred in the first postoperative month. The indication for initial keratoplasty did not influence the rupture rate. In comparison, the general rate of penetrating eye injuries in the population was 2.2/100,000 per annum. The rupture rate for extracapsular cataract surgery was 1/221 (0.45%) and 0/6450 for phacoemulsification. Both of these rates were significantly less than after penetrating keratoplasty (P=0.005, P<0.0001).

DISCUSSION

Penetrating keratoplasty cases have a higher rate of globe rupture than other ocular procedures. There are 5 important time periods of wound integrity after penetrating keratoplasty. The highest risk period is the month following surgery, when wound strength is derived almost entirely from sutures. The 18 months following surgery are moderately high risk. The month following removal of sutures is a second high-risk period. In the 6 months following this, the wound has a similar strength to the first postoperative year. Following penetrating keratoplasty the cornea never regains its preoperative strength and remains at risk for traumatic rupture for the remainder of the patient's life.

The management of corneal trauma: advances in the past twenty-five years

Over the past quarter century, advances in our understanding of corneal anatomy, physiology, and wound healing have all played an integral role in the management of corneal trauma. As the etiologies of corneal trauma have changed, so has our understanding of the impact of injury on corneal function as it relates to visual rehabilitation. Numerous new classes of antibiotics, antiinflammatory agents, and tissue adhesives have emerged. Occlusive therapy has advanced from simple pressure patching bandage soft contact lenses and collagen shields. Surgical instrumentation, operating microscopes, viscoelastic substances, and suture materials have all improved the outcomes of corneal trauma repair. Improved understanding of the refractive properties of the cornea through topography and alternative suture techniques has helped us restore the natural corneal curvature and visual outcomes. Consequently, in the last quarter of this century our therapeutic approaches to cornea trauma, both medical and surgical, have improved.

Load bearing and deformation characteristics of monofilament nylon 66 and their implications for ophthalmic surgery

The load bearing and deformation characteristics of monofilament nylon 66 have been examined. This material has been shown to have increased strength and altered deformation properties compared to bulk nylon. These features are beneficial in its role as a corneal suture. However, the load bearing performance of monofilament nylon 66 has been shown to be influenced by the manner in which it is stressed, making the task of producing identical stitches difficult. Moreover, a period of rapid relaxation has been shown to occur immediately after installation which makes the time taken to install the suture a critical factor in its subsequent performance. These factors, which are essentially beyond the control of the ophthalmic surgeon, must surely play a significant role in the inconsistent post operative results seen.