Robert A. H. Scott

The effect of pars plana vitrectomy on cystoid macular oedema associated with chronic uveitis: a randomised, controlled pilot study

Aim: To evaluate the efficacy of pars plana vitrectomy (PPV) in the management of chronic uveitic cystoid macular oedema (CMO). Methods: A prospective, interventional, randomised, controlled, pilot study. 23 eyes of 23 patients with CMO secondary to chronic intermediate or posterior uveitis unresponsive to medical treatment were randomised into a surgical (group S) or medical group (group M). 12 patients in group S underwent PPV as opposed to 11 patients in group M who received systemic corticosteroid and/or immunosuppressive treatment during the study period. The primary outcome measures of the study were change in visual acuity and angiographic appearance of CMO at 6 months. Results: Mean visual acuity in group S improved significantly from 1.0 (0.62) at baseline to 0.55 (0.29) at 6 months following vitrectomy (p = 0.011), with five (42%) eyes reaching vision of 20/40 or better. Conversely, mean visual acuity in group M improved only marginally by 0.03 (0.27) (p = 0.785). CMO after vitrectomy was angiographically improved in four (33%) eyes, remained unchanged in seven (58%) eyes, and deteriorated in one (8%) eye. In the medical group, fluorescein leakage decreased in one eye, did not alter in four eyes, and deteriorated in two eyes. Conclusion: PPV for macular oedema secondary to chronic uveitis despite angiographic improvement in only one third of the patients, seems to have a significant beneficial effect on visual function. This study provides enough evidence to justify a large scale trial which would define the role of vitrectomy in uveitic macular oedema.

Visual and anatomical results of surgery for long standing macular holes

AIMS To determine the visual and anatomical outcome of surgery for long standing idiopathic macular holes. METHODS A retrospective review of 24 eyes of all 22 patients who underwent surgery for idiopathic full thickness macular holes (FTMH) symptomatic for between 1 and 3 years. Postoperative follow up was for 6 months. Preoperative and postoperative visual acuities were recorded as well as the presence of anatomical closure of the hole. RESULTS The mean duration of symptoms was 18.21 (SD 5.42) months). Anatomical closure of the FTMH was achieved in 17 (70.8%) of the eyes at 6 months. The logMAR acuity of the group where closure was achieved improved by a mean of 0.31, equivalent to a change of Snellen acuity from 6/60 to 6/29. Where the hole remained open the acuity deteriorated by a mean logMAR of 0.11 lines, equivalent to a change of Snellen acuity from 6/60 to 5/60. Anatomical closure of the hole was associated with a significantly improved acuity over non-closure (p<0.001). The degree of visual improvement was independent of the preoperative visual acuity (Spearman correlation coefficient 0.03, p=0.888), though preoperative acuity was related to the final acuity (Spearman correlation coefficient 0.701, p<0.001). Over the study period, six patients required cataract surgery, one patient developed secondary glaucoma, and one a retinal detachment. CONCLUSIONS Vitrectomy with intraocular gas tamponade and postoperative posturing is a well tolerated and effective intervention for long standing macular holes. Anatomical closure of the macular hole is associated with a significant improvement in visual acuity.

Exposure to liquid detergent capsules: A study undertaken by the UK National Poisons Information Service

Objective. To ascertain the reported toxicity of liquid detergent capsules. Methods. Between 1 March 2008 and 30 April 2009 the UK National Poisons Information Service collected prospectively 647 telephone enquiries relating to liquid detergent capsules. Results. The majority of enquiries (96.1%) concerned children of 5 years of age or less. Exposure to these products occurred mainly as a result of ingestion alone (n = 518; 80.1%), with eye contact alone (n = 61; 9.4%), and skin contact alone (n = 7; 1.1%) being less common; multiple routes of exposure were involved in 61 (9.4%) enquiries. Following ocular exposure, conjunctivitis with or without eye pain (n = 61), eye pain alone (n = 11) and keratitis (n = 4) developed; in one case the keratitis persisted for nine days, though recovery occurred in all cases as far as is known. The most common features reported following ingestion alone were nausea and vomiting (n = 143), followed by coughing (n = 21). Eleven children less than 2 years of age also developed drowsiness. A rash occurred in nine patients where ingestion was considered to be the route of exposure, probably due to topical contact with the capsule. Seven children aged 3 or less were exposed via the dermal route alone and developed rash (n = 4), irritation (n = 2), chemical burn (n = 2), and paresthesia (n = 1). Conclusions. Ocular exposure may lead to conjunctivitis and keratitis; recovery is to be expected in all cases within 7–10 days. Ingestion may also result in drowsiness. Greater consumer awareness is required to reduce injury from liquid detergent capsules, particularly that involving the eye. Parents have a vital role to play in ensuring that these products are stored safely at all times.

Exploiting mTOR Signaling: A Novel Translatable Treatment Strategy for Traumatic Optic Neuropathy?

Retinal ganglion cell (RGC) death and a failure of axon regeneration contribute to the profound visual loss experienced by patients after traumatic optic neuropathy (TON), for which there are no effective treatments. Experimental manipulations of cellular signaling pathways in animal models have demonstrated that neuronal survival and axon regeneration in the mature central nervous system (CNS) are possible, and increased understanding of the molecular basis of prosurvival and regenerative signals has led to the identification of candidate targets for novel therapeutic strategies. The axogenic pathway is activated sequentially, after growth factor/receptor binding, through phosphoinositide-3-kinase (PI3K) and the downstream serine/threonine kinase Akt. Akt is a nodal point for the regulation of growth cone dynamics by glycogen synthase kinase (GSK3β) and axon protein synthesis/RGC survival by the mammalian target of rapamycin (mTOR). The mTOR signaling pathway has a pivotal role in numerous cellular processes. It is active during development, but downregulated in the mature CNS and further suppressed by axonal injury, and experimental upregulation of mTOR signaling promotes RGC survival and axon regeneration after optic nerve crush injury. However, several translational challenges remain, including understanding the regulatory mechanisms of axotomy-induced mTOR and GSK3β signaling, and the disparity between the RGC survival and axon regenerative effects. In this review, we explore the molecular basis of RGC regenerative failure and assess the potential for manipulations of mTOR signaling as a novel translatable treatment for TON.

The injured eye

Eye injuries come at a high cost to society and are avoidable. Ocular blast injuries can be primary, from the blast wave itself; secondary, from fragments carried by the blast wind; tertiary; due to structural collapse or being thrown against a fixed object; or quaternary, from burns and indirect injuries. Ballistic eye protection significantly reduces the incidence of eye injuries and should be encouraged from an early stage in Military training. Management of an injured eye requires meticulous history taking, evaluation of vision that measures the acuity and if there is a relative pupillary defect as well as careful inspection of the eyes, under anaesthetic if necessary. A lateral canthotomy with cantholysis should be performed immediately if there is a sight-threatening retrobulbar haemorrhage. Systemic antibiotics should be prescribed if there is a suspected penetrating or perforating injury. A ruptured globe should be protected by an eye shield. Primary repair of ruptured globes should be performed in a timely fashion. Secondary procedures will often be required at a later date to achieve sight preservation. A poor initial visual acuity is not a guarantee of a poor final result. The final result can be predicted after approximately 3–4 weeks. Future research in eye injuries attempts to reduce scarring and neuronal damage as well as to promote photoreceptor rescue, using post-transcriptional inhibition of cell death pathways and vaccination to promote neural recovery. Where the sight has been lost sensory substitution of a picture from a spectacle mounted video camera to the touch receptors of the tongue can be used to achieve appreciation of the outside world.

High resolution Optical Coherence Tomography demonstration of membranes spanning optic disc pits and colobomas.

Objectives: To demonstrate the features of optic disc pits and colobomas revealed by high-resolution optical coherence tomography (OCT) and their association with the development of maculopathy. Methods: Subjects with disc pits or colobomas and no other ocular history underwent full ophthalmic examinations including logMAR visual acuity and contrast sensitivity. Fundus photographs and high-resolution OCT images were obtained. Results: Seven patients were identified with optic disc pits or colobomas aged 25 to 63 years. Five patients had a unilateral optic disc pit, one had a unilateral disc coloboma, and another had bilateral disc colobomas. Apart from one eye with a grossly anomalous disc, vision was logMAR 0.4 or better in all eyes. In three of five eyes without maculopathy, a complete membrane could be identified traversing the optic disc cup that was absent or deficient in the three eyes with maculopathy. One patient with optic disc pit and marked schisis-like separation of the retinal layers throughout the macula was asymptomatic with logMAR visual acuity of 0.0 and normal achromatic contrast sensitivity. Conclusions: In this small series of patients with optic disc pits or colobomas, it was possible to identify a membrane spanning the optic disc cup, and it is speculated that this may protect against the development of maculopathy. Schisis-like separation of retinal layers can be associated with normal visual function.

Ophthalmic injuries in British Armed Forces in Iraq and Afghanistan

AimBritish military ophthalmologists have not been deployed in support of operations since 2003. Eye injuries in British forces receive definitive treatment on return to the United Kingdom. We report the injury patterns, management strategies, and outcomes for eye injuries in British Armed Forces in Iraq and Afghanistan.MethodsRetrospective consecutive case series of eye injuries in British Armed Forces in Iraq or Afghanistan from July 2004 to May 2008. Outcomes assessed by final best-corrected visual acuity (VA; few patients lost to follow-up), rates of endophthalmitis, and proliferative vitreoretinopathy (PVR).ResultsThere were 630 cases of major trauma, 63 sustained eye injuries (10%), and 48 sustained significant eye injuries. There were 21 open-globe injuries: 9 ruptures and perforating injuries, of which 7 were enucleated/eviscerated; 11 intraocular foreign body (IOFB) injuries, of which 1 was eviscerated. Primary repair was combined with posterior segment reconstruction in 9/11 cases with IOFB. Mean time to primary repair was 1.9 days (range 0–5). Intravitreal antibiotics were given at primary repair in five cases. All cases received early broad-spectrum systemic antibiotics. Median final VA was logMAR 0.25 excluding evisceration/enucleations. There were two cases of PVR and none of endophthalmitis.ConclusionsThe number of eye injuries as a proportion of all casualties is lower than recently reported. The injuries are more severe than in civilian practise. The outcomes were comparable with previous reports, this demonstrates that, in certain cases, primary repair can be safely delayed beyond 24 h in the patients best interests, in order to optimise the conditions for treatment.

Animal models of retinal injury.

Retinal injury is a common cause of profound and intractable loss of vision. Clinical outcomes are poor in both open and closed globe injuries because cell death, scarring, and a failure of tissue and axon regeneration are not ameliorated by current treatments. Much animal research is directed at understanding and modifying these pathologies, although results have yet to translate into clinical practice. Axotomy-induced retinal ganglion cell (RGC) death in mammals can be effectively reduced and axon regeneration enhanced over the short term. After retinal injury in mammals, the retinal pigment epithelium (RPE) and retinal glia either regenerate lost RPE and neuroretinal cells or form nonfunctional scars. An understanding of the mechanisms underlying injury responses is critical to the successful development of therapeutic strategies to promote ocular repair.

The effect of pars plana vitrectomy in the management of fuchs heterochromic cyclitis

Purpose Fuchs heterochromic cyclitis (FHC) is characterized by a unilateral chronic iridocyclitis of insidious onset and uncertain cause. Our aim was to evaluate the effect of vitreous surgery in patients with FHC and clinically significant visual symptoms caused by inflammatory vitreous debris. Methods This study was a review of 12 eyes of 12 consecutive patients with FHC who underwent pars plana vitrectomy for visually significant vitreous opacities. Cataract extraction with posterior chamber lens implantation had been performed on four eyes preoperatively. Four eyes had a concomitant lensectomy for cataracts, and one had a surgical posterior capsulotomy. Visual and anatomic data were recorded before surgery and for at least 6 months after surgery. Results Visual acuity improved in all patients from an average logMAR of 0.57 to 0.007 (P = 0.0004) and by more than 2 Snellen lines in 8 of 12 of the eyes (P < 0.05). Symptoms of floaters resolved in all 11 patients in whom they were a symptom. Vitreous haze was cleared completely from an average Nussenblatt grade of 1.7 to 0 after 1 week (P = 0.0001). Conclusions Pars plana vitrectomy is a safe and effective treatment for the visual symptoms associated with FHC and can be combined safely with a lensectomy if required.

Reported toxicity in 1486 liquid detergent capsule exposures to the UK National Poisons Information Service 2009–2012, including their ophthalmic and CNS effects

Abstract Context. Data on the ophthalmic and central nervous system (CNS) adverse effects of liquid detergent capsules (liquid laundry pods) are limited. Objective. To ascertain the reported toxicity of liquid detergent capsules, particularly their ophthalmic and CNS adverse effects, in a large case series. Methods. Between 1 May 2009 and 30 July 2012 the UK National Poisons Information Service collected prospectively 1509 telephone enquiries (involving 1486 exposures) relating to liquid detergent capsules. Results. The majority of patients (95.6%) were children aged less than 5. Exposure to these products occurred mainly as a result of ingestion alone (n = 1215; 81.8%), with eye contact alone (n = 110; 7.4%), and skin contact alone (n = 20; 1.3%) being less common; multiple routes of exposure were involved in 141 (9.5%) cases. Following ocular exposure (n = 212), features suggesting conjunctivitis (n = 145; 68.4%) and corneal ulceration (n = 6; 2.8%) developed. The most common features reported following ingestion alone were nausea and vomiting (n = 721; 59.3%), followed by coughing (n = 53; 4.4%), drowsiness/CNS depression (n = 49; 42 of these were children were aged 2 years or less) and foaming at the mouth (n = 47; 3.9%). A rash occurred in 22 patients where ingestion was considered to be the route of exposure. Twenty patients were exposed via the dermal route alone and developed erythema (n = 9), rash (n = 6) and burn (n = 3). Conclusions. Ocular exposure to liquid detergent capsules may lead to conjunctivitis and corneal ulceration; detergent ingestion may result in central nervous system (CNS)depression. Greater consumer awareness is required to reduce injury from liquid detergent capsules, particularly that involving the eye.