<p>Factors predicting change in corneal astigmatism following suture removal in post-penetrating keratoplasty patients</p>

Abstract

PurposeTo identify factors predicting corneal astigmatic change following suture removal in post-penetrating keratoplasty patients.Patients and methodsThis cross-sectional study included the data of 33 events of corneal suture removal from 27 post-penetrating keratoplasty patients. Sutures were removed from the steep axis of transplanted cornea with 16 interrupted corneal sutures. Corneal astigmatism was measured before and after suture removal using ORBSCAN II. Patients’ demographic data and corneal biomechanics parameters obtaining from the Corvis ST were recorded. The changes in corneal astigmatism were calculated using vector analysis. The correlation between changes in corneal astigmatism and the potential factors was evaluated using Spearman’s correlation coefficient and linear regression model.ResultsThe mean corneal astigmatism before and after suture removal was 7.1±3.7 diopters (D) and 5.5±3.2D, respectively. The mean astigmatic change was 7.0±6.3D (range, 0.3–30.8D) by vector analysis at 9.7±5.5 weeks after suture removal. Change in corneal astigmatism was significantly correlated with pre-suture removal astigmatism (Rs=0.47, P=0.01). There was no correlation between the donor-recipient trephine diameter difference, the duration from corneal transplantation to suture removal, the number of removed sutures with the change in corneal astigmatism, and corneal biomechanics parameters (P>0.05). Linear regression is given by the following equation: astigmatic change (D)=1.05x pre-suture removal astigmatism (D) - 0.43.ConclusionThe astigmatic change after corneal suture removal in post-keratoplasty patients was significantly correlated with pre-suture removal astigmatism. These findings will permit a validated approach for reducing corneal astigmatism in post-keratoplasty patients.

Update on Suture Techniques in Corneal Transplantation: A Systematic Review

“…Oversized grafts had higher astigmatism (6.44 D vs. 4.17, p < 0.01). However, four years later, a randomized control trial denied this association, concluding that oversizing up to 0.5 mm had no worsening effect on corneal astigmatism [33], and this was supported by a more recent work [34]. In 2003, a large prospective study [35] on 480 eyes who underwent PK with DCS investigated the influence of graft diameter (7 vs. 7.5 vs. 8 mm) on astigmatism.…”

Recent Advances in Hydrogels: Ophthalmic Applications in Cell Delivery, Vitreous Substitutes, and Ocular Adhesives

“…Along with corneal incisions performed during cataract surgery, corneal injuries can simply self-heal; however, severe corneal injuries most commonly require suturing or adhesives [ 108 ]. As mentioned earlier, suturing comes with its various drawbacks, including astigmatism, tissue damage, and endophthalmitis [ 17 , 18 , 19 , 20 , 21 ]. Suturing also requires a skillful surgeon and is not the ideal wound closure method when compared to other wound closure alternatives.…”

“…There are different surgical methods; generally, a corneal incision is made followed by the removal of the natural lens, and the replacement of the lens with an intraocular lens (IOL) [ 16 ]. Current methods of corneal incision closure are via sutures which run the risk of tissue damage and corneal astigmatism [ 17 , 18 , 19 , 20 ]. Furthermore, a postoperative visit is required to remove the sutures, and the method poses risks if removal is delayed [ 21 , 22 ].…”

Loose suture-related ocular surface inflammation and activation of conjunctiva-associated lymphoid tissue in patients after keratoplasty

“… 2 . Damaged or loosened corneal sutures have been identified as a major risk factor for graft infection and graft rejection, which may affect the success rate of corneal transplantation 3 , 4 . However, why loose sutures can cause these complications remains unclear.…”