Biomedical Research Center for Ophthalmology

London, United Kingdom

Biomedical Research Center for Ophthalmology

London, United Kingdom
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De Silva D.J.,Moorfields Eye Hospital | Khaw P.T.,Moorfields Eye Hospital | Khaw P.T.,Biomedical Research Center for Ophthalmology | Khaw P.T.,University College London | Brookes J.L.,Moorfields Eye Hospital
Journal of AAPOS | Year: 2011

Purpose: To evaluate the long-term outcome of primary congenital glaucoma in patients followed for more than 20 years. Methods: All patients with a diagnosis of congenital glaucoma who were examined in the pediatric glaucoma clinic at Moorfields Eye Hospital from 2005 to 2006 were included. The follow-up period was a minimum of 20 years; patients with pediatric glaucoma secondary to other etiologies were excluded. Data collected included visual acuity, optic disk cupping, intraocular pressure (IOP), corneal diameter, pachymetry, visual fields, refraction, strabismus, glaucoma management, and ocular comorbidity. Progressive congenital glaucoma, defined as an increase of the cup/disk ratio of >0.2 secondary to elevated IOP, was evaluated with the use of Kaplan-Meier survival curves. Patients were divided into 1of 3 groups: (1) stable glaucoma with no visual impairment; (2) glaucoma progression with sight-threatening consequences; and (3) poor visual acuity as a result of ocular comorbidity. Results: A total of 30 eyes of 16 patients were identified. Mean follow-up was 34 ± 10 years (range, 22-59 years). At the final clinical assessment, mean IOP was 13.6 ± 4.3 mm Hg and mean cup/disk ratio was 0.7 ± 0.3 (p < 0.05). Survival analysis demonstrated lack of progression in 90.3% at 1 year, 83.1% at 5 years, 70.8% at 10 years, 58.3% at 34 years, and 48.6% at 40 years. Conclusions: Apparently stable congenital glaucoma may progress with sight-threatening complications after many years of IOP stability. Monitoring of these patients is indicated throughout life. Copyright © 2011 by the American Association for Pediatric Ophthalmology and Strabismus.

Fayers T.,East Surrey Hospital | Shaw S.R.,Moorfields Eye Hospital | Hau S.C.,Moorfields Eye Hospital | Ezra D.G.,Moorfields Eye Hospital | And 2 more authors.
British Journal of Ophthalmology | Year: 2015

Background The aetiology of blepharospasm remains unclear. There is evidence that the afferent pathway is important, but this area remains under-researched. Aim To explore the hypothesis that the afferent arm of the blink reflex is abnormal in blepharospasm by assessing a range of measures of corneal sensory function. Methods In this prospective case-control study, 21 patients with blepharospasm and 21 age-matched and gender-matched controls completed the Ocular Surface Disease Index questionnaire and underwent the following assessments: tear osmolarity, Shirmer test, tear-film break up time, corneal and conjunctival vital staining, meibomian gland dysfunction, corneal aesthesiometry and confocal microscopy. Results Corneal sensitivity was significantly lower in patients with blepharospasm than in controls (right eyes p=0.009; left eyes p=0.009, paired t test). The median number of main nerve trunks was lower for patients with blepharospasm than for controls, and this was statistically significant at the 5% level (p=0.04, paired t test). Mean nerve density, median number of nerve branches and median total number of nerves were lower for blepharospasm cases than controls, but this did not reach statistical significance. Tortuosity was greater for blepharospasm cases than controls, but this was not statistically significant. Conclusions Blepharospasm is associated with reduced corneal aesthesiometry and a tendency towards a reduced number of nerves in the sub-basal plexus, implying an impairment in corticosensory processing, possibly a defect of the sensorimotor gating mechanism resulting in a loss of inhibition of the blink reflex.

Pearce E.,Moorfields Eye Hospital | Crossland M.D.,Moorfields Eye Hospital | Crossland M.D.,University College London | Rubin G.S.,University College London | Rubin G.S.,Biomedical Research Center for Ophthalmology
British Journal of Ophthalmology | Year: 2011

Background/aims: Hospital-based low vision services in the UK typically involve one consultation with an optometrist. In this study we investigated the effect of adding further low vision device training. Methods: Participants were recruited from those attending their first low vision assessment (LVA). Participants completed the Mass of Activity Inventory (MAI) questionnaire by telephone before their appointment. After LVA, participants were randomised to an intervention group (who received a further appointment to review device handling) or a control group. The MAI was readministered 1 and 3 months after the initial LVA. MAI data were converted to Rasch scores for goal difficulty. Results: Ninety-six participants completed the study. Both groups experienced a significant improvement in goal difficulty following low vision intervention (p<0.0001), equivalent to a visual acuity improvement of approximately 0.55 logarithm of the minimum angle of resolution (logMAR). There was no significant difference in improvement between the group randomised to the training visit and those in the control arm (p=0.80). Conclusion: Self-perceived difficulty with daily visual tasks decreases following a low vision appointment. An additional visit for device handling training resulted in no further improvement. This could be due to the relatively simple nature of the devices prescribed in this clinic. Trial registration number: ISRCTN05434212.

Macedo A.F.,University College London | Macedo A.F.,University of Minho | Crossland M.D.,University College London | Crossland M.D.,Biomedical Research Center for Ophthalmology | And 2 more authors.
Investigative Ophthalmology and Visual Science | Year: 2011

PURPOSE. To assess the effect on visual acuity of compensating fixation instability by controlling retinal image motion in people with macular disease. METHODS. Ten patients with macular disease participated in this study. Crowded and noncrowded visual acuity were measured using an eye tracking system to compensate for fixation instability. Four conditions, corresponding to four levels of retinal image motion, were tested: no compensation (normal motion), partial compensation (reduced motion), total compensation (no motion), and overcompensation (increased motion). Fixation stability and the number of preferred retinal loci were also measured. RESULTS. Modulating retinal image motion had the same effect on crowded and noncrowded visual acuity (P = 0.601). When fixation instability was overcompensated, acuity worsened by 0.1 logMAR units (P < 0.001) compared with baseline (no compensation) and remained equal to baseline for all other conditions. CONCLUSIONS. In people with macular disease, retinal image motion caused by fixation instability does not reduce either crowded or noncrowded visual acuity. Acuity declines when fixation instability is overcompensated, showing limited tolerance to increased retinal image motion. The results provide evidence that fixation instability does not improve visual acuity and may be a consequence of poor oculomotor control. © 2011 The Association for Research in Vision and Ophthalmology, Inc.

Dunbar H.M.P.,Institute of Ophthalmology | Crossland M.D.,Institute of Ophthalmology | Crossland M.D.,Biomedical Research Center for Ophthalmology | Rubin G.S.,Institute of Ophthalmology | Rubin G.S.,Biomedical Research Center for Ophthalmology
Investigative Ophthalmology and Visual Science | Year: 2010

PURPOSE. Impaired fixation stability is associated with reduced reading speed. In previous research, fixation stability has been assessed using an infrared eye tracker or a confocal scanning laser ophthalmoscope. The new MP-1 microperimeter from Nidek Technologies (Padova, Italy) provides another option for the assessment of fixation. Here the authors compare fixation stability values measured using the MP-1 microperimeter and the Rodenstock scanning laser ophthalmoscope (SLO; Rodenstock GmbH, Munich, Germany) in persons with and without diabetic maculopathy. METHODS. Sixteen normally sighted volunteers and 21 patients with diabetic maculopathy were recruited. Fixation stability was recorded monocularly on the SLO and the MP-1 in counterbalanced order while participants fixated a red 1° cross. Fixation data collected from each instrument were used to calculate a bivariate contour ellipse area (BCEA) that encompassed 68% of fixation points. RESULTS. For control subjects, MP-1 BCEA values were larger than SLO by 0.25 log min arc2, though the difference was small (10%) and of borderline significance (MP-1, 2.51 log min arc2; SLO, 2.26 log min arc2; P = 0.06). In patients with diabetic maculopathy there was no significant difference between MP-1 and SLO values (MP-1, 2.94 log min arc2; SLO, 2.90 log min arc2; P = 0.88). CONCLUSIONS. No significant difference was found in BCEA values from the SLO and MP-1 in control subjects and patients with diabetic maculopathy. The authors suggest that the similarity between BCEA values, together with the consistent and reliable operation of the MP-1, make it a useful and viable alternative to the SLO in the assessment of fixation. © Association for Research in Vision and Ophthalmology.

Shortt A.J.,University College London | Tuft S.J.,Moorfields Eye Hospital NHS Foundation Trust | Daniels J.T.,Biomedical Research Center for Ophthalmology
British Medical Bulletin | Year: 2011

Introduction or background: Corneal opacity is a common cause of blindness. The majority of cases result from ulceration and scarring following infection or trauma, but in a proportion corneal epithelial stem cell (SC) deficiency leads to an inability to maintain a healthy corneal surface.Sources of data: This review includes systematic reviews and individual case series of treatments for corneal epithelial SC deficiency.Areas of agreement: Two techniques such as transplantation of large segments of cornea from a healthy eye and ex vivo expansion of corneal SCs in the laboratory were compared. Both have merits and their clinical outcomes are similar. The smaller biopsy in the cell expansion approach has less risk for the donor eye, which is a significant advantage.Areas of controversy: Treatment algorithms for different aetiologies of SC failure are evolving. The proportion of true corneal epithelial SCs in ex vivo culture is unclear and it is unknown whether these cells survive long term.Growing points: In this study, the optimum method of cell culture and transplantation is being intensively investigated.Areas timely for developing research: Development of tissues using multiple cell types, genetic modification to treat hereditary corneal disorders and development of cell therapy for other eye diseases are future possibilities. © 2011 The Author.

Crossland M.D.,University College London | Crossland M.D.,Biomedical Research Center for Ophthalmology | Rubin G.S.,University College London | Rubin G.S.,Biomedical Research Center for Ophthalmology
Optometry and Vision Science | Year: 2012

PURPOSE.: Contrast sensitivity is reduced in people with eye disease, and also in older adults without eye disease. In this article, we compare contrast of text presented in print and digital formats with contrast sensitivity values for a large cohort of subjects in a population-based study of older adults (the Salisbury Eye Evaluation). METHODS.: Contrast sensitivity values were recorded for 2520 adults aged 65 to 84 years living in Salisbury, Maryland. The proportion of the sample likely to be unable to read text of different formats (electronic books, newsprint, paperback books, laser print, and LED computer monitors) was calculated using published contrast reserve levels required to perform spot reading, to read with fluency, high fluency, and under optimal conditions. RESULTS.: One percent of this sample had contrast sensitivity less than that required to read newsprint fluently. Text presented on an LED computer monitor had the highest contrast. Ninety-eight percent of the sample had contrast sensitivity sufficient for high fluent reading of text (at least 160 words/min) on a monitor. However, 29.6% were still unlikely to be able to read this text with optimal fluency. CONCLUSIONS.: Reduced contrast of print limits text accessibility for many people in the developed world. Presenting text in a high-contrast format, such as black laser print on a white page, would increase the number of people able to access such information. Additionally, making text available in a format that can be presented on an LED computer monitor will increase access to written documents. Copyright © 2012 American Academy of Optometry.

Luhmann U.F.O.,University College London | Carvalho L.S.,University College London | Robbie S.J.,University College London | Cowing J.A.,University College London | And 6 more authors.
Experimental Eye Research | Year: 2013

Monocytes, macrophages, dendritic cells and microglia play critical roles in the local immune response to acute and chronic tissue injury and have been implicated in the pathogenesis of age-related macular degeneration. Defects in Ccl2-Ccr2 and Cx3cl1-Cx3cr1 chemokine signalling cause enhanced accumulation of bloated subretinal microglia/macrophages in senescent mice and this phenomenon is reported to result in the acceleration of age-related retinal degeneration. The purpose of this study was to determine whether defects in CCL2-CCR2 and CX3CL1-CX3CR1 signalling pathways, alone or in combination, cause age-dependent retinal degeneration. We tested whether three chemokine knockout mouse lines, Ccl2-/-, Cx3cr1-/- and Ccl2-/-/Cx3cr1-/-, in comparison to age-matched C57Bl/6 control mice show differences in subretinal macrophage accumulation and loss of adjacent photoreceptor cells at 12-14 months of age. All mouse lines are derived from common parental strains and do not carry the homozygous rd8 mutation in the Crb1 gene that has been a major confounding factor in previous reports. We quantified subretinal macrophages by counting autofluorescent lesions in fundus images obtained by scanning laser ophthalmoscopy (AF-SLO) and by immunohistochemistry for Iba1 positive cells. The accumulation of subretinal macrophages was enhanced in Ccl2-/-, but not in Cx3cr1-/- or Ccl2-/-/Cx3cr1-/- mice. We identified no evidence of retinal degeneration in any of these mouse lines by TUNEL staining or semithin histology. In conclusion, CCL2-CCR2 and/or CX3CL1-CX3CR1 signalling defects may differentially affect the trafficking of microglia and macrophages in the retina during ageing, but do not appear to cause age-related retinal degeneration in mice. © 2012 Elsevier Ltd.

West E.L.,University College London | Pearson R.A.,University College London | Barker S.E.,University College London | Luhmann U.F.O.,University College London | And 7 more authors.
Stem Cells | Year: 2010

Stem cell therapy presents an opportunity to replace photoreceptors that are lost as a result of inherited and agerelated degenerative disease. We have previously shown that murine postmitotic rod photoreceptor precursor cells, identified by expression of the rod-specific transcription factor Nrl, are able to migrate into and integrate within the adult murine neural retina. However, their long-term survival has yet to be determined. Here, we found that integrated Nrl.gfp+ve photoreceptors were present up to 12 months post-transplantation, albeit in significantly reduced numbers. Surviving cells had rod-like morphology, including inner/outer segments and spherule synapses. In a minority of eyes, we observed an early, marked reduction in integrated photoreceptors within 1 month post-transplantation, which correlated with increased numbers of amoeboid macrophages, indicating acute loss of transplanted cells due to an inflammatory response. In the majority of transplants, similar numbers of integrated cells were observed between 1 and 2 months post-transplantation. By 4 months, however, we observed a significant decrease in integrated cell survival. Macrophages and T cells were present around the transplantation site, indicating a chronic immune response. Immune suppression of recipients significantly increased transplanted photoreceptor survival, indicating that the loss observed in unsuppressed recipients resulted from T cell-mediated host immune responses. Thus, if immune responses are modulated, correctly integrated transplanted photoreceptors can survive for extended periods of time in hosts with partially mismatched H-2 haplotypes. These findings suggest that autologous donor cells are optimal for therapeutic approaches to repair the neural retina, though with immune suppression nonautologous donors may be effective. © AlphaMed Press.

Ford R.L.,Central Middlesex Hospital | Lee V.,Central Middlesex Hospital | Xing W.,Biomedical Research Center for Ophthalmology | Bunce C.,Biomedical Research Center for Ophthalmology
Journal of AAPOS | Year: 2012

Background: To report epidemiologic data on traumatic optic neuropathy (TON) in patients less than 18 years of age in the United Kingdom acquired by prospective population-based active surveillance through the British Ophthalmic Surveillance Unit. Methods: Data were obtained from incident and 6-month follow-up questionnaires sent to reporting ophthalmologists over a period of 2 years. Main outcome measures were demographic data, clinical and visual function at presentation and follow-up, investigations, and treatments used. Results: A total of 26 cases (21 males) were identified; follow-up data were available for 23 (88%). Minimum estimated annual incidence was 0.99 cases per million. Leading causes of TON included 6 sports injuries (23%), 5 falls (19%), and 4 traffic accidents (16%). Presenting best-corrected visual acuity was ≤6/60 in 15 cases (58%), with no light perception in 7 cases (27%). Associated injuries were as follows: nonpenetrating injuries, 8 (31%); adnexal injuries, 3 (11.5%); orbital fractures, 5 (19%); skull fractures, 3 (12%); intracranial bleeding, 1 (4%). Fourteen (54%) received no treatment, and 9 (35%) were treated with steroids. Final visual acuity improved in 7 of 21 patients (33%), with 13 of 23 (56%) achieving final visual acuity ≤6/60, 10 of whom (43%) had no light perception. Baseline visual acuity was associated with last follow-up visual acuity (P = 0.03), but treatment and improvement of visual acuity by at least 3 lines were not associated. Treatment was more common in children with poor presenting vision (P = 0.03). Conclusions: The incidence, natural history, poor presenting visual acuity, and male prevalence of TON in children appear similar to adults in adults in the UK. Copyright © 2012 by the American Association for Pediatric Ophthalmology and Strabismus.

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