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.

Accuracy of biometric formulae in hypermetropic patients undergoing cataract surgery.

PURPOSE: To audit and analyse the accuracy of current biometric formulae on refractive outcomes following cataract surgery in patients with axial length less than 22 mm. METHODS: A total of 84 eyes from 84 patients with axial length <22 mm were identified from consecutive patients undergoing cataract surgery retrospectively at a single university hospital. All subjects had biometry using the IOLMaster (Carl Zeiss Meditec, Inc, Dublin, CA, USA) and a Sensar AR40 intraocular lens implant (Abbott Medical Optics, CA, USA). One eye from each patient was randomly selected for inclusion. Prediction errors were calculated by comparing expected refraction from optimized formulas (SRK/T, Hoffer Q, Haigis and Holladay 1) to postoperative refraction. A national survey of ophthalmologists was conducted to ascertain biometric formula preference for small eyes. RESULTS: The mean axial length was 21.00 ± 0.55 mm. Mean error was greatest for Hoffer Q at -0.57 dioptres. There was no significant difference in mean absolute error between formulae. SRK/T achieved the highest percentage of outcomes within 0.5 dioptres (45.2%) and 1 dioptre (76.2%) of target. Shallower anterior chamber depth was associated with higher mean absolute error for SRK/T (p = 0.028), Hoffer Q (p = 0.003) and Haigis (p = 0.016) but not Holladay (p = 0.111). CONCLUSION: SRK/T had the highest proportion of patients achieving refractive results close to predicted outcomes. However, there was a significant association between a shallower anterior chamber depth and higher mean absolute error for all formulae except Holladay 1. This suggests that anterior chamber depth with axial length should be considered when counselling patients about refractive outcome.

Risk stratifying retinal breaks.

OBJECTIVE: Argon laser retinopexy has been the primary treatment for retinal breaks for many decades. Prevention of progression to retinal detachment (RD) is the main objective. The benefit of laser retinopexy is well documented, although little has been reported on the risk factors for progression to RD. By addressing this issue, patients at high risk can be identified, and more timely specialist retinal input can be sought. METHODS: Data over a 6-month period from 45 consecutive patients undergoing laser retinopexy were reviewed. Patients were categorized into complete success (no more than 1 laser treatment), qualified success (no more than 3 laser or cryotherapy treatments), and treatment failure (more than 3 laser or cryotherapy treatments or progression to RD). RESULTS: Complete success was observed in 53.5% of patients, a further 34.9% of patients achieved a qualified success, and the remainder of the patients (11.6%) fell into the treatment failure category. About 9.3% of patients required cryotherapy, and 7.0% of patients underwent RD surgery. Patients with a bridging blood vessel and vitreous hemorrhage were significantly more likely to be in the treatment failure category than those without. RD was significantly associated with the presence of vitreous hemorrhage. CONCLUSIONS: Patients with retinal breaks associated with bridging blood vessels and vitreous hemorrhage are at greater risk for poorer outcome. The area of subretinal fluid was not linked to failure. If complete laser of a tear is not possible or if concerns remain regarding treatment efficacy, prompt referral to a retina specialist for further management is recommended.

Spontaneous resolution of a rhegmatogenous retinal detachment after normal labor and childbirth.

PURPOSE: The purpose of this study was to describe a patient with an untreated rhegmatogenous retinal detachment, first diagnosed during pregnancy, that underwent spontaneous resolution after normal labor and childbirth. METHODS: Descriptive case report. RESULTS AND DISCUSSION: It has been extensively documented that normal labor and childbirth are safe in the context of rhegmatogenous retinal detachment. Although exudative retinal detachment is a well-known complication of preeclampsia, spontaneous reattachment of a rhegmatogenous retinal detachment is a rare phenomenon. In this case, labor-induced physiologic changes may have contributed to the resolution of the detachment.

Tear production and corneal sensitivity in diabetes.

AIM: Diabetic patients are at significant risk of developing corneal lesions such as superficial punctate keratitis, recurrent corneal erosions, persistent epithelial defects, and microbial keratitis. The aim of this study was to investigate whether diabetes mellitus is correlated with both reduced corneal sensation and reduced tear production. METHODS: In 25 type II diabetic patients with a history of retinopathy only and in 25 nondiabetic control subjects (age and sex matched), we performed noncontact corneal aesthesiometry and assessed basal tear production using Schirmer's test with topical anesthesia. The noncontact corneal aesthesiometer (NCCA) is a new noninvasive device for quantifying threshold corneal sensitivity. RESULTS: The diabetic patients demonstrated a significantly reduced Schirmer's test result (P<.001) and significantly reduced corneal sensitivity (P<.01). CONCLUSION: Our study supports previous reports of reduced basal tear production, lending more support to the theory of a peripheral neuropathy affecting lacrimal gland function in diabetes. We also confirmed reduced threshold corneal sensitivity in diabetic patients using the NCCA.

Corneal endothelial evaluation after phacoemulsification and silicone oil removal via an anterior approach.

PURPOSE: To determine the effect of simultaneous phacoemulsification and silicone oil removal via an anterior approach on the endothelial cell density (ECD). METHODS: In this prospective study, the authors measured the ECD before and 6 weeks after surgery using an automatic noncontact specular endothelial microscope. Nine patients underwent phacoemulsification and silicone oil removal via an anterior approach using a closed system and separation of irrigation/aspiration function. RESULTS: Of nine patients, four (five eyes) were diabetic and five (five eyes) were nondiabetic. The postoperative ECD of the entire population was statistically different (P<0.01) from baseline and the average endothelial cell loss was 6.7%. CONCLUSIONS: Combined phacoemulsification and silicone oil removal via an anterior approach using a close system and separation of irrigation/aspiration function is safe to the corneal endothelium.

Trypan blue to aid visualization of the vitreous during anterior segment surgery.

We describe the usefulness of intracameral injection of trypan blue to highlight vitreous in the anterior chamber. The technique was used in 3 eyes of 3 patients who had vitreous prolapse in the anterior chamber. Trypan blue 0.06% was injected in the anterior chamber under air to visualize and resect the prolapsed vitreous. Trypan blue stained the clear vitreous and improved visualization for a safe and atraumatic vitrectomy. No complications associated with the dye were found.

Does a small central Nd:YAG posterior capsulotomy improve peripheral fundal visualisation for the vitreoretinal surgeon?

BACKGROUND: To evaluate the effect of Nd:YAG capsulotomy for posterior capsular opacification (PCO) on visualisation of the peripheral fundus with scleral indentation. METHODS: Patients undergoing Nd:YAG capsulotomy for PCO were examined pre- and four weeks post- Nd:YAG capsulotomy. In order to give a quantitative measure of visualisation of the peripheral retina, a novel scalar measurement was developed. Changes in the degree of visualisation following Nd:YAG capsulotomy were calculated. RESULTS: There was a significant improvement in fundal visualisation of the retinal periphery with scleral indentation following Nd:YAG capsulotomy (p = 0.001). CONCLUSION: Peripheral fundal visualisation with scleral indentation improves following a small central Nd:YAG capsulotomy. This finding is important in relation to the detection of peripheral pseudophakic retinal breaks, particularly in those patients deemed at high risk following Nd:YAG capsulotomy.

Complete occlusion of the anterior capsular opening by fibrocellular membrane associated with retained silicone oil: a clinicopathologic correlation.

BACKGROUND: To report the clinicopathologic features of a fibrocellular membrane in a pseudophakic eye with retained silicone oil in the absence of any capsular contraction syndrome, necessitating repeat anterior capsulorhexis. METHODS: Clinicopathologic report of a case. RESULTS: Histopathologic study of the membrane showed absence of any true periodic acid Schiff-positive capsule within the specimen. Clinically, there was no evidence of any anterior capsular contraction. The fibrocellular membrane may have occurred as a result of inflammatory and mechanical effects of silicone oil in the anterior chamber or as a result of the intraocular lens design. CONCLUSION: The authors report the clinicopathologic features of a fibrocellular membrane occluding the anterior capsular opening in a pseudophakic eye with retained silicone oil, in the absence of any capsular contraction. The stimulus for its formation may have been the inflammatory and mechanical effects of retained silicone oil in the anterior chamber.

Effect of the Honan intraocular pressure reducer in sub-Tenon's anesthesia.

PURPOSE: To ascertain whether the Honan intraocular pressure reducer (HIPR) has an effect on the preoperative intraocular pressure (IOP), surgeon's assessment of anesthesia, and patients' analgesic experience when sub-Tenon's anesthesia is used for routine cataract surgery. SETTING: Princess Alexandra Eye Pavilion, Edinburgh, Scotland. METHOD: Forty-five eyes of 45 patients having routine phacoemulsification cataract surgery were randomized to receive 10 minutes of ocular compression using the HIPR or no compression after administration of sub-Tenon's anesthesia. The IOP was measured immediately before and immediately and 10 minutes after sub-Tenon's anesthesia administration using a standard technique. One surgeon who was masked to the randomization process performed all injections and completed a questionnaire on aspects of the anesthetic block. Patients scored their level of analgesia during surgery. RESULTS: The mean rise in IOP immediately after administration of sub-Tenon's anesthesia was 1.39 mm Hg +/- 3.91 (SD) (95% confidence interval +0.22 to 2.57; P =.021). In the 22 patients who received compression, there was a mean IOP reduction of 4.20 +/- 2.74 mm Hg at 10 minutes. The mean difference between the compression and no-compression groups at 10 minutes was 4.99 mm Hg (P<.0001). There was no difference in the surgeon's scores for any aspect of the sub-Tenon's anesthesia (P>.05). All patients reported good levels of analgesia. CONCLUSIONS: There was a significant reduction in IOP after compression using the HIPR. However, the rise in IOP after administration of sub-Tenon's anesthesia was small and the use of the HIPR did not make a significant difference in the effectiveness of the anesthesia to the surgeon or patients.

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.