Methods
We present a single centre, retrospective, continuous comparative study of all patients who had primary laser retinopexy from January 2017 to 2020 at Birmingham and Midland Eye Centre, in the UK. All data were extracted from electronic patient records (Medisoft Ophthalmology, Medisoft Limited, Leeds, UK). The research adhered to the tenets of the Declaration of Helsinki and all patient data extracted were anonymised for analysis.
Our cohort of patients was divided into four groups: primary retinopexy performed by ST2–3, ST4–5, ST6–7 and VR specialists. VR specialists were defined as VR fellows and consultants. No VR associate specialists or non-fellows operate in our unit. The most junior residents, on completion of retinopexy, would typically have the application reviewed by a senior resident, otherwise follow-up in the VR clinic would be arranged. If a senior resident/clinician took over to complete the retinopexy, the most senior clinician would be labelled as the operator.
Our primary outcome measure was to compare RRD rate within 6 months following primary retinopexy by training grade. We also assessed the requirement for further retinopexies following primary retinopexy by training grade as secondary outcomes. All patients who had prior VR surgery were excluded. RRD rate was defined as requiring RRD surgery within 6 months of having primary retinopexy in the same eye. Retinopexy of retinal breaks was achieved with laser, via a slit lamp or indirect method and consisted of surrounding retinal breaks with several rows of confluent white laser burns using either a contact lens or a non-contact condensing lens system. Indirect laser was generally used in patient’s intolerant of slit lamp retinopexy (requiring additional local anaesthetic and difficult positioning), small pupils, specific pseudophakic patients (due to the intraocular lens edge obstructing the view of the tear), anterior breaks requiring scleral indentation and retinal tears present with concurrent vitreous haemorrhage where indentation helped provide a view. All patients undergoing primary retinopexy were reviewed within 4 weeks, depending on clinical urgency, in a VR specialist clinic. If patients were subsequently found to have inadequate chorioretinal scar cover, further retinopexy was applied. Patients occasionally presented to our emergency eye clinic with deteriorating symptoms and could be clinically determined to require further retinopexy. All the cases that required retinal detachment surgery following primary retinopexy were performed with transconjunctival 23-gauge pars plana vitrectomy, vitreous-base trim and cryotherapy/laser retinopexy or cryotherapy and/or scleral buckling. As a tertiary referral centre, patients whose postcode was outside, our catchment area was excluded as these patients may have had further retinopexy or surgery at the referring unit. Preoperative data collection included indication for retinopexy: retinal break morphology (horseshoe tears (HST), operculated breaks, round holes), lattice degeneration, RRD (treated with retinopexy alone), other), treatment modality (slit lamp and indirect laser) age, gender and presence of high myopia (≤−6.00 Dioptres). Postoperative data collection included the 6-month RRD rate and repeat retinopexy rate.
Statistical analysis
Statistical significance was defined as p<0.05. Prior to analysis, normality of continuous variables was assessed using the Shapiro-Wilk test and found not to be normally distributed. Hence, data are primarily reported as medians and IQRs throughout. Kruskal Wallis test was used to compare three or more independent groups, respectively, for continuous variables. A χ2 test was used for nominal variables with three or more categories. There were multiple factors that could affect outcome (age, gender, tear morphology (HST compared with round holes), presence of high myopia) and selection bias of treatment modality. Therefore, a multivariable Cox regression survival analysis was performed analysing both repeat retinopexy and RRD rate. Time in days to repeat retinopexy and RRD were used, respectively, with training grade (ST2–3, ST4–5 and ST6–7 compared with VR specialist as reference covariate), gender, age, high myopia and treatment modality (indirect retinopexy compared with reference of slit lamp laser) and indication for treatment (HST vs hole), as covariates.
All statistical analyses were performed using IBM SPSS Statistics for Windows, V.27.0 (IBM, Armonk, New York).