JCRS HIGHLIGHTS

Collagen crosslinking: New hope for more advanced ectatic disease?

JCRS provides an issue featuring a collection of papers on collagen crosslinking (CXL). Eight full-length articles highlight the evolution of the understanding of this treatment for corneal ectatic disease. In a lead editorial William Dupps MD notes that investigators are grappling for evidence- based answers to questions such as who can benefit most from CXL and which treatment modalities are most effective. Several of the studies in this issue incorporate prospective designs, documentation of pretreatment disease progression and contralateral controls to elevate the level of clinical evidence and the likelihood that valid answers will emerge. The papers reflect some of the most pressing and elusive questions in clinical CXL and add more voices, some dissenting, to key controversies, he notes.

- WJ Dupps et al., JCRS, “Effective corneal collagen crosslinking in advanced cases of progressive keratoconus”, Volume 39, Issue 8, 1131-1132.

Corneal ring segments plus CXL

One open question in keratoconus treatment concerns the potential benefit of combining corneal ring segments and ultraviolet-A and riboflavin collagen crosslinking (CXL). Accordingly, researchers conducted a retrospective comparative case series study to evaluate the efficacy of single or paired intrastromal corneal ring segments combined with CXL in 74 patients with keratoconus. Consecutive patients with keratoconus had femtosecond laser- assisted ring segment implantation combined with same-day CXL between 2008 and 2011. Some 47 eyes of 40 patients received paired segments while 38 eyes of 34 patients received single rings segments. The uncorrected distance visual acuity was significantly improved after single ICRS (3.4 lines; P=.04) and paired ring segment (2.7 lines; P=.01) implantation combined with CXL. Corrected distance visual acuity remained stable. The single and paired ICRS groups had a significant reduction in mean cylinder at one year (single ICRS: −3.84 dioptres [D] ± 1.72 [SD] versus −2.19 ± 1.54 D, P=.02; paired ICRS: −3.91 ± 1.45 D versus −2.96 ± 1.92 D) (P=.02). There was no significant difference in total higher order aberrations. No patient lost lines of CDVA.

- Sonia N. Yeung et al., JCRS, “Efficacy of single or paired intrastromal corneal ring segment implantation combined with collagen cross linking in keratoconus”, Volume 39, Issue 8, Pages 1146-1151.

Femto laser retreatment

LASIK has evolved into a predictable refractive surgery technique with reports of good long-term stability. Nonetheless, a significant number of patients require a second surgery, referred to as a retreatment or enhancement, to correct residual refractive errors after LASIK. Investigators studied the utility of creating an additional side cut within the old laser LASIK flap using a femtosecond laser to reduce the incidence of epithelial ingrowth in patients having retreatments for residual refractive errors after LASIK. In a comparative case series 24 eyes of 18 patients had femtosecond laser-assisted retreatment with side cut only, while 103 eyes of 80 patients had a flap-lift LASIK enhancement. Twenty-seven cases of epithelial ingrowth were identified in the two groups, four cases (17 per cent) in the side-cut group and 23 cases (22 per cent) in the flap-lift group. There was a statistically significant difference between the two groups in the incidence of epithelial ingrowth in patients in which the microkeratome was used as the initial method of flap creation.

- PK Vaddavalli et al., JCRS, “Femtosecond laser-assisted retreatment for residual refractive errors after laser in-situ keratomileusis”, Volume 39, Issue 8, 1241- 1247.