Title - Long term outcomes of vitrectomy and ERM peel: Can pre-operative metamorphopsia measured using the D-Chart help improve surgical candidate selection?

PURPOSE: To assess the predictive value of pre-operative metamorphopsia, measured using the D-Chart, in patients undergoing epiretinal membrane (ERM) surgery and how this relates to improvement in quality of life after surgery. METHODS: 17 patients from vitreo-retinal surgery clinics at a tertiary ophthalmology centre were recruited when listed for pars plana vitrectomy (PPV) with ERM peel between September 2019 - February 2020. Pre-operatively patients underwent visual acuity (VA), Visual-Function Index 14 (VF-14) and metamorphopsia (D-Chart-Thomson Software Solutions) assessment and answered a questionnaire regarding cardinal ERM symptoms. Post-operatively patients were re-assessed in the same domains. RESULTS: 13 patients completed the protocol (inclusion rate 76%) with a mean follow-up of 32.1 (± 3.1) months. Mean pre-operative VA of the affected eye was 0.42 logMAR (± 0.25). Mean pre-operative VF-14 score was 81.51 (± 12.8) and mean M-Score of the affected eye was 14.6 (± 12.7). Post-operatively, mean VA of the operated eye was 0.11 logMAR (± 0.11), mean VF-14 score was 97.4 (± 3.8) and mean M-Score was 1.31 (± 2.8). Mean improvement in VA was 0.31 logMAR (p < 0.001), in VF-14 15.9 (p = 0.002), and M-Score -13.3 (p = 0.003). There was a significant association between pre-operative D-Chart score and improvement in VA (r = -0.570, p = 0.042), visual functioning (r = 0.606 p = 0.028) and metamorphopsia (r = 0.916 p < 0.001), with those demonstrating poorer D-Chart scores showing greater improvements. CONCLUSION: Pre- and post-operative visual distortion measured using the D-Chart, correlates with vision related quality of life in patients undergoing epiretinal membrane surgery. Patients with worse pre-operative distortion scores noticed the greatest improvements in distortion and vision related quality of life following surgery. With a mean follow-up time of 32.1 months, this long-term follow-up data further reinforces the efficacy of vitrectomy and ERM peel by demonstrating significant and sustained improvement in visual acuity, metamorphopsia and visual functioning. The authors suggest there is a role for D-Chart assessment pre-operatively to improve selection of patients in ERM surgery.

Patient comfort during clear corneal phacoemulsification with sub-Tenon's local anesthesia.

PURPOSE: To assess patient comfort with and without intravenous (i.v.) cannulation during 1-quadrant sub-Tenon's anesthesia during phacoemulsification. SETTING: Royal Alexandra Hospital, Paisley, Scotland, United Kingdom. METHODS: This prospective masked controlled clinical trial comprised 119 patients having elective clear corneal phacoemulsification. Fifty had sub-Tenon's anesthesia with an i.v. cannula; 23, sub-Tenon's anesthesia without an i.v. cannula; and 46, topical anesthesia of proparacaine 0.5% without an i.v. cannula. No patient received sedation. All patients had clear corneal phacoemulsification with foldable posterior chamber intraocular lens implantation. The patients' subjective pain experience was measured immediately after surgery by a single independent observer using a 10-point visual analog scale. RESULTS: The mean patient-reported pain was low in all 3 groups. The mean i.v. cannula-related pain score in the sub-Tenon's group with an i.v. cannula (1.00; range 0 to 8) was higher than the mean general pain score (0.46; range 0 to 5) and worst pain experienced during surgery score (0.64; range 0 to 3). In the topical anesthesia group, 8 patients (17%) reported greater discomfort directly or indirectly related to the subconjunctival antibiotic injection at the end of surgery. CONCLUSION: Patient-reported pain caused by placing an i.v. cannula in the sub-Tenon's group significantly altered overall patient comfort during the surgical experience. Thus, the routine use of i.v. access during clear corneal phacoemulsification under sub-Tenon's anesthesia should be avoided to improve patient satisfaction.