Direct Exchange of PerfluoroCarbon Liquid for Silicone Oil: A Surgical Technique to Control Pressure and Avoid Retinal Slippage.

BACKGROUND/PURPOSE: Perfluorocarbon heavy liquid (PFCL) is used in vitreoretinal surgery to flatten the unsupported detached retina before insertion of silicone oil in cases of giant retinal tear or relaxing retinectomy. Direct exchange of PFCL for silicone oil is recommended to reduce retinal slippage when compared with fluid-air exchange, but it is commonly regarded as a difficult procedure. We describe our technique for direct PFCL-silicone oil exchange using a 20-gauge drainage cannula, reliably avoiding the complications of retinal slippage and high intraoperative intraocular pressure. METHODS: We present a consecutive case series of patients undergoing PFCL-oil exchange and explain, using Poiseuille's equation for laminar fluid flow through a cannula, the rationale for using a 20-gauge drainage cannula rather than smaller gauges to avoid high intraocular pressure. RESULTS: Twenty-six patients underwent PFCL-oil exchange from February 1, 2019, to September 30, 2019. There was no intraoperative retinal slippage or pressure-related complications. Postoperatively 20 patients underwent oil removal. Six suffered retinal redetachment, and 14 remained attached. The vision postoil removal ranged from 6/6 to hand movements. CONCLUSION: We are confident that the PFCL-oil exchange technique described here is reliable and safe. The use of a 20-gauge drainage cannula is recommended regardless of vitrectomy gauge.

Investigating the Role of Optometrists in Teleophthalmology and the Implications of Increasing Access to Advanced Imaging Techniques and Digital Referral: A Systematic Search and Review.

Introduction: The objective of this systematic search and review was to investigate the role of optometrists in teleophthalmology and digital referral. We examine the implications of the optometric communities' increasing access to advanced imaging, such as optical coherence tomography (OCT), in ophthalmic telemedicine schemes. Methods: A systematic search was conducted, using PubMed and Embase, in April of 2019. Eight hundred eight (n = 808) texts were retrieved and 99 articles were deemed eligible for full-text review. Twenty-six (n = 26) studies were included in the qualitative synthesis. All studies involved optometrists as principal service providers. Results: Findings demonstrate that optometrist-facilitated teleophthalmology results in consistent reductions in hospital referrals and waiting times, as well as high patient satisfaction. Optometrists are identified as crucial to the success of many projects and their access to advanced imaging technology is observed to position optometry practices as the most convenient location to establish a teleophthalmology program. OCT imaging demonstrated the potential to increase diagnostic accuracy and is increasingly prevalent in optometry practice. The importance of additional training for optometrists participating in teleophthalmology schemes is highlighted, as is the need for appropriate remuneration for those involved. Conclusion: The role of community-based ophthalmic care in reducing demands on hospital eye services (HES) is highlighted by our results, demonstrating that optometrist-facilitated teleophthalmology can dramatically reduce referrals and streamline care. In addition, the increasing prevalence of OCT in optometric practice represents an underutilized resource for HES.

The case for intraocular delivery of PPAR agonists in the treatment of diabetic retinopathy.

BACKGROUND: Systemic therapeutics targeting the peroxisome proliferator-activated receptors have been found to be beneficial in the treatment of diabetic retinopathy. In this paper, we provide a rationale for the use of these therapeutics as intraocular agents. In addition, we introduce the peroxisome proliferator-activated receptors and describe their functions in response to the drugs. DISCUSSION: Based on the evidence of large-scale clinical studies investigating the systemic administration of fenofibrate, this ligand for peroxisome proliferator-activated receptor-α is potentially a good candidate for intraocular delivery. Here, we describe the mechanisms by which it might be acting to improve diabetic retinopathy, its relative safety and we speculate on how it could be developed for intraocular delivery. SUMMARY: In this paper, we provide a rationale for the further investigation of peroxisome proliferator-activated receptor-α agonists as intraocular agents for the treatment of diabetic retinopathy.

Iris-fixated phakic intraocular lens explantation.

BACKGROUND/AIMS: To evaluate the visual outcomes and indication for surgery in a series of patients who underwent explantation of a phakic intraocular lens (PIOL). METHODS: A retrospective case series of patients who underwent PIOL explantation in our institution was performed. The indication for explantation and visual and refractive outcomes were examined. The method of explantation is described. RESULTS: Twenty-two eyes of 16 patients underwent PIOL explantation with a mean time to explantation of 7 ± 3 years (range 3-11.4). The mean age at explantation was 50.3 ± 9.3 years. Sixteen Artisan PIOLs and six Artiflex PIOLs were explanted. The indications for explanation were cataract development (17/22), endothelial cell loss (4/22) and synechiae formation (1/22). All patients with cataract underwent a combined procedure with explantation and phacoemulsification and the placement of a posterior chamber IOL. Mean corrected vision after explantation was 0.22 ± 0.10 logMAR (range 0.1-0.3 logMAR). One patient with endothelial cell loss required a Descemet's Stripping Endothelial Keratoplasty (DSEK). CONCLUSION: Removal of PIOLs was necessitated most frequently by cataract followed by endothelial cell loss. Both explantation alone and explantation with concurrent phacoemulsification are safe procedures with good visual outcomes and will become more frequent in the future as more patients with PIOLs reach cataractous age.

Persistent pseudomyopia following a whiplash injury in a previously emmetropic woman.

PURPOSE: Accommodative spasm, which manifests as ciliary muscle spasm, convergent strabismus or miosis, is a recognised consequence of head trauma. In whiplash cases, cervical spine hyperextension poses a risk of contra-coup injury and brainstem trauma, and is known to affect the visual system. However, to date, no cases of accommodative spasm due to whiplash injury have been reported. OBSERVATIONS: We present the case of a 34-year-old female who developed sudden onset blurred distance vision after a rear impact car crash, having previously been emmetropic. Her unaided distance visual acuity was 20/70 in the right eye and 20/20 in the left. Best-corrected visual acuity in the right eye was 20/20 with a correction that progressed from -1.75 to -3.50 DS over the 12 months following the accident.This patient's sudden unilateral myopia, with unilaterally increased amplitude of accommodation suggests pseudomyopia due to accommodative spasm. Magnetic resonance imaging showed no evidence of injury to her brain stem, frontal lobes or oculomotor nerve. The patient is now well adjusted with a -3.50DS corrective lens for the right eye. CONCLUSIONS AND IMPORTANCE: The accommodation reflex is susceptible to injury at the occipital lobe, frontal eye fields, Edinger-Westphal nuclei and oculomotor nerves. As such it should be examined in patients who present with visual disturbances following whiplash injury.It is important that such cases are identified at presentation, as early intervention can improve outcomes in accommodative spasm and reduce the long term psychological effects often associated with whiplash injuries.

Opportunistic detection of glaucomatous optic discs within a diabetic retinopathy screening service.

PURPOSE: To determine the prevalence of glaucoma among patients referred to a glaucoma service with suspicious disc photographs from the diabetic retinopathy (DR) screening program. METHODS: A clinical audit of all patients attending a single-center DR screening program in the Mater Misericordiae University Hospital, Dublin, between July 2010 and October 2011 was conducted with a minimum follow-up of 30 months. The DR screening service uses trained technician graders to assess 2-field color retinal photographs for the features of DR. Recently, the service was enhanced so that optic discs are also assessed for signs of glaucoma. RESULTS: In the 16-month study period, 3,697 diabetic patients were photographed. Following photograph grading, 91 (2.46%) were judged to require referral for assessment at the glaucoma clinic. Of these, 63 (69.23%) presented for assessment. Thirteen patients (20.63%) were diagnosed with glaucoma, comprising 7 cases of low-tension glaucoma and 6 cases of primary open-angle glaucoma. Thirty-six patients (57.14%) were classified as glaucoma suspects and 14 patients (22.22%) were discharged back to the DR screening program following normal ocular examination. Only 6 (9.52%) of the 63 patients examined had an intraocular pressure greater than 21 mm Hg. CONCLUSIONS: The assessment of DR screening photographs for signs of glaucomatous optic nerve damage should be considered as part of a strategy to improve glaucoma case detection and to reduce the burden of this disease on society.

Corneal inlay implantation complicated by infectious keratitis.

BACKGROUND/AIMS: To report five cases of infectious keratitis following corneal inlay implantation for the surgical correction of presbyopia. METHODS: This was a retrospective, observational case series. Five eyes of five patients were identified consecutively in two emergency departments during a 1-year period, from November 2013 to November 2014. Patients' demographics, clinical features, treatment and outcomes are described. RESULTS: There were four female patients and one male, aged 52-64 years. Three patients had the KAMRA inlay (AcuFocus) and two had the Flexivue Microlens inlay (Presbia Coöperatief U.A.) inserted for the treatment of presbyopia and they presented from 6 days to 4 months postoperatively. Presenting uncorrected vision ranged from 6/38 to counting fingers. One patient's corneal scrapings were positive for a putatively causative organism, Corynebacterium pseudodiphtheriticum, and all patients responded to broad-spectrum fortified topical antibiotics. All patients lost vision with final uncorrected visual acuity ranging from 6/12 to 6/60 and best-corrected vision ranging from 6/7.5 to 6/12. Two patients' corneal inlays were explanted and three remained in situ at last follow-up. CONCLUSIONS: Infectious keratitis can occur at an early or late stage following corneal inlay implantation. Final visual acuity can be limited by stromal scarring; in the cases where the infiltrate was small and off the visual axis at the time of presentation, the final visual acuity was better than those patients who presented with larger lesions affecting the visual axis. Though infection may necessitate removal of the inlay, early positive response to treatment may enable the inlay to be left in situ.

Twelve-month follow-up of the Artiflex toric phakic intraocular lens.

PURPOSE: To evaluate the efficacy, safety, refractive predictability, and complications 12 months following the implantation of a foldable toric phakic intraocular lens (PIOL) for the correction of myopic astigmatism. METHODS: Uncorrected visual acuity (UCVA) and best-corrected distance visual acuity (CDVA), subjective and objective manifest refraction, endothelial cell count (ECC), intraocular pressure, biomicroscopy findings, and patient-reported symptoms were the main parameters recorded pre and post the implantation of an Artiflex toric PIOL. RESULTS: Twenty-eight eyes of 19 patients with preoperative myopia ranging from -1.00 D to -12.00 D and with astigmatism ranging from -1.00 D to -5.50 D had the Artiflex toric PIOL inserted to correct refractive error. Postoperatively, all eyes had UCVA of at least 6/12, 94% of at least 6/9, and 58% of at least 6/6. The CDVA improved in 38% of eyes and vision deteriorated by one line in one eye. Postoperative mean refractive spherical equivalent was -0.25 D (range -1.25 D to 0.00 D) with mean astigmatism being -0.60 D (range -1.50 D to 0.00 D). The ECC decreased by a mean of 6.17% (SD 5.63%) at 12 months when compared with the preoperative baseline. CONCLUSION: The Artiflex toric PIOL is an efficacious, predictable, and safe method of treating moderate to high refractive error with astigmatism.

Thiazolidinediones in the treatment of HIV/HAART-associated lipodystrophy syndrome.

The treatment of HIV-1 infected patients with HAART has resulted in long-term suppression of viral replication and reduced progression to AIDS. However, the use of HAART has been associated with adverse effects, including metabolic dysregulation and changes in body fat deposition. This syndrome, known as HIV/HAART-associated lipodystrophy syndrome, is characterized by insulin resistance, dyslipidemia, lipodystrophy, and increased visceral adiposity, which contribute to an increased risk of cardiovascular disease amongst these patients. The thiazolidinediones are a class of agonists for the nuclear receptors, the peroxisome proliferator-activated receptor. Since peroxisome proliferator-activated receptor is critically involved in the regulation of insulin sensitivity and lipid metabolism, a number of clinical trials have analyzed whether thiazolidinediones could ameliorate the signs of HIV/HAART-associated lipodystrophy syndrome. Based on these trials, thiazolidinediones appear to up-regulate peroxisome proliferator-activated receptor-dependent genes such as adiponectin, an effect that could have important physiological benefits in the long-term for HIV/HAART-associated lipodystrophy syndrome patients. Critically, many of the studies were of short duration and thus the beneficial effects of thiazolidinediones might have been missed. In addition, the few studies on the thiazolidinedione pioglitazone showed a beneficial effect on limb fat mass that was not associated with a pro-atherogenic lipid profile. Based on these studies, a large-scale clinical trial of pioglitazone use in HIV/HAART-associated lipodystrophy syndrome patients is warranted.