Cosmetic outcome of femtosecond laser-assisted pterygium surgery.

BACKGROUND: To examine the cosmetic outcome of femtosecond laser-assisted pterygium surgery (FLAPS) with conjunctival autograft (CAG) and its potential predictive factors. METHODS: This was a prospective interventional case series (NCT02866968). We included 29 patients (29 eyes) with primary pterygium who underwent FLAPS. Cosmetic outcome was graded by two graders (an ophthalmology resident and an experienced ophthalmologist) using Hirst classification system (1-4 = excellent-poor). Weighted Cohen's kappa analysis was performed to examine the intra- and inter-rater reliability. The relationship between cosmetic outcome and various factors were determined by Spearman's correlation coefficients (r). RESULTS: The preoperative severity of pterygium (Tan grading system) was mild/atrophic (7%), moderate/intermediate (62%), and severe/fleshy (31%). An ultrathin CAG (mean thickness of 74.5 ± 9.8 µm) was fashioned intraoperatively. An excellent cosmetic outcome of FLAPS (median ± IQR) was observed at 3 months (1.0 ± 1.0) and remained similar at 6 months (1.0 ± 0.0) and 12 months (1.0 ± 0.0) postoperatively. At final follow-up, 27 (93%) patients achieved good-to-excellent cosmetic outcome, with 1 (3%) patient having a poor outcome due to incomplete pterygium removal. Weighted kappa analysis of Hirst grading system showed excellent intra-rater (κ = 0.86-0.95) and inter-rater reliability (κ = 0.84-0.88). There was a weak and borderline significant correlation between good cosmetic outcome and reduced postoperative CAG thickness (r = 0.38, P = 0.06) but not with age, gender, preoperative pterygium severity, or intraoperative CAG thickness. CONCLUSIONS: FLAPS can result in an excellent cosmetic outcome, which may be attributed to the beneficial effect of an ultrathin CAG. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02866968 . Registered in July 2016.

Proposal and validation of a new grading system for pterygium (SLIT2).

BACKGROUND/AIMS: To propose and validate a new pterygium grading system based on slit-lamp evaluation. METHODS: This prospective cross-sectional study included 217 patients with pterygium. All patients underwent slit-lamp examination, and slit-lamp photographs were independently graded by two graders twice. A total of eight parameters were evaluated and all parameters were assigned with a score of 1-4 (normal-severe). Intra-rater and inter-rater reliability as determined by weighted Cohen's kappa analysis. RESULTS: A total of 868 independent assessment, based on 217 slit-lamp images, were performed by two graders. For conjunctival assessment, the intra-rater reliability was excellent for body thickness (κ=0.81-0.89) and size at limbus (κ=0.87-0.92), substantial-to-excellent for body vascularity (κ=0.72-0.86), and moderate-to-excellent for body length (κ=0.57-0.81), whereas the inter-rater reliability was excellent for size at limbus (κ=0.86), substantial for body thickness (κ=0.72-0.73) and body vascularity (κ=0.66-0.75), and moderate for body length (κ=0.54-0.57). For corneal assessment, the intra-rater reliability was excellent for all four parameters (κ=0.84-0.90) whereas the inter-rater reliability was excellent for head length (κ=0.86-0.87), substantial-to-excellent for head vascularity (κ=0.78-0.82), substantial for Stocker's line (κ=0.79-0.80) and head thickness (κ=0.67-0.69). The grading system was named SLIT2, which included S tocker's line, S ize at limbus, L ength of head/body, I njection/vascularity of body/head, and T hickness of body/head. CONCLUSION: The proposed SLIT2 grading system, consisting of eight components, may serve as a reliable tool to standardise the reporting of pterygium severity and disease recurrence for clinical and research applications.

Validation of the Use of Automated and Manual Quantitative Analysis of Corneal Nerve Plexus Following Refractive Surgery.

Following refractive surgery, the cornea is denervated and re-innervated, hence a reproducible tool to objectively quantify this change is warranted. This study aimed to determine the repeatability and reproducibility of corneal nerve quantification between automated (ACCMetrics) and manual software (CCMetrics) following refractive surgery. A total of 1007 in vivo confocal microscopy images from 20 post-small incision lenticule extraction (SMILE) or post-laser-assisted in situ keratomileusis (LASIK) patients were evaluated by two independent observers using CCMetrics for corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fibre length (CNFL). Intra-observer and inter-observer reproducibility and repeatability, as well as agreement and correlation between the measurements obtained by ACCMetrics and CCMetrics, were assessed. We found that CNFL demonstrated the best intra- and inter-observer agreement followed by CNFD (intra-class correlation coefficient (ICC) = 0.799 and 0.740, respectively for CNFL; 0.757 and 0.728 for CNFD). CNBD demonstrated poorest intra- and inter-observer ICC. There was an underestimation in ACCMetrics measurements compared to CCMetrics measurements, although the differences were not significant. Our data suggested that both automated and manual methods can be used as reliable tools for the evaluation of corneal nerve status following refractive surgery. However, the measurements obtained with different methods are not interchangeable.

Femtosecond Laser-assisted Preparation of Conjunctival Autograft for Pterygium Surgery.

Femtosecond laser-assisted conjunctival autografts (CAG) preparation was recently proposed. This study reports the outcomes of the first clinical trial on the use of laser to prepare CAG in pterygium surgery, and to compare the outcomes with those of manual technique. Forty eyes undergoing primary pterygium excision with laser-assisted CAG transplantation were prospectively included (L group). Two historical matched cohorts whose CAGs were prepared manually were compared (n = 78 eyes by the same experienced surgeon, M group; n = 78 eyes by trainees; TM group). We found the laser-created CAGs had only 11 µm deviation from the targeted thickness. The best-corrected visual acuity improved, and the astigmatism significantly decreased after surgery, with comparable efficacy across 3 groups. The 1-year recurrence rate was 2.5%, 3.8% and 7.7% in the L, M and TM groups, respectively (P = 0.12). There was no significant difference between the L and M groups in the complication rate (5.0% and 1.3%, respectively), surgical time (19.4 ± 5.1 and 19.1 ± 6.2 minutes, respectively), and postoperative discomfort scores (0.1 ± 0.3 and 0.2 ± 0.3, respectively), but these outcomes were significantly less favorable in the TM group. The results of this first comparative clinical trial suggest that femtosecond laser-assisted CAG preparation can be considered as an alternative technique for CAGs preparation.