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PURPOSE Fell's modification of the Harada-Ito (HI) procedure is often used to tackle subjective torsion usually following superior oblique palsy. There is limited published data on the longer-term outcomes and the effect on horizontal incomitance of the procedure. The purpose of this study is to report on the medium to long-term outcomes of the HI procedure. MATERIALS AND METHODS A retrospective review of 20 patients who had all undergone a single surgeon modified HI procedure to correct subjective torsion was undertaken. Follow-up data were analyzed in relation to stability of torsion measurements, the effect on vertical incomitance of horizontal deviation and the final treatment outcome. RESULTS There was a significant reduction in median maximum torsion from preoperative to immediately post-op (p

Background Falls are the second leading cause of accidental deaths worldwide mainly in older people. Older people have poor vision and published evidence suggests that it is a risk factor for falls. Less than half of falls clinics assess vision as part of the multi-factorial assessment of older adults at risk of falls despite vision being an essential input for postural stability. The aim of our study was to investigate the relationship between all clinically assessed visual functions and falls amongst older adults in a prospective observational individually age-matched case control study. Methods Visual acuity (VA), contrast sensitivity (CS), depth perception, binocular vision and binocular visual field were measured using routinely used clinical methods in falls participants (N = 83) and non-falls participants (N = 83). Data were also collected on socio-demographic factors, general health, number of medications, health quality, fear of falling and physical activity. Logistic regression analysis was carried out to determine key visual and non-visual risk factors for falls whilst adjusting for confounding covariates. Results Older adults have an increased risk of experiencing a fall if they have reduced visual function (odds ratio (OR): 3.49, 1.64-7.45, p = 0.001), specifically impaired stereoacuity worse than 85” of arc (OR: 3.4, 1.20-9.69, p = 0.02) and reduced (by 0.15 log unit) high spatial frequency CS (18 cpd) (OR:1.40, 1.12-1.80, p = 0.003). Older adults with a hearing impairment are also at higher risk of falls (OR: 3.18, 95% CI: 1.36-7.40, p = 0.007). The risk decreases with living in a less deprived area (OR: 0.74, 0.64-0.86, Conclusions The combination of social, behavioural and biological determinants are significant predictors of a fall. The non-visual risk factors include older adults, living in deprived neighbourhoods, socialising less outside of the home and those who have a hearing impairment. Impaired functional visual measures; depth perception and contrast are significant visual risk factors for falls above visual acuity.

BACKGROUND Myasthenia gravis (MG) often presents with ocular signs that mimic other forms of ocular defects, such as isolated cranial nerve palsy. Normal velocity or even hyperfast saccadic eye movements in the presence of deficits of smooth pursuit have been well described in the literature in myasthenic patients. The reason for these paradoxical clinical findings has been reported to be due to increased postsynaptic folding of the fast-twitch fibers responsible for the execution of a saccade which is absent in those fibers responsible for slower, smooth eye movement. Saccadic characteristics therefore offer a point of differential diagnosis between patients suspected of having ocular motility deficits as a result of MG and those caused by other neuropathies. The advent of portable quantitative saccadic assessment means that previously laboratory-based assessments that require specialist equipment and training may now be undertaken clinically, providing a noninvasive test that can aid the differential diagnosis of the condition. The aim of this pilot study was to investigate the feasibility of the saccadometer (Ober Consulting, Poznan, Poland) in detecting the saccadic characteristics associated with myasthenia, specifically normal peak velocity (PV) in a group of patients confirmed with myasthenia. METHODS A group of 5 patients with a confirmed diagnosis of MG were recruited from a single site into the study along with 5 age-matched healthy volunteers. All myasthenic patients had ocular signs such as underaction or limitations of motility confirmed through ocular clinical examination. Healthy volunteers were screened for any underlying ocular motility or neurological defects before inclusion within the study. All participants undertook 100 trials of both 10 and 20° amplitude saccades, and mean PV, amplitude, and latency were recorded using the saccadometer for each individual. Overall, mean PV, amplitude, and latency were collated for both myasthenic and healthy control groups for each saccade size and compared. RESULTS The mean PV was significantly greater (481 ± 103.5 deg/seconds) for myasthenic patients compared with healthy controls (384 ± 42.8 deg/seconds) (P < 0.05) in 10° saccades. PV was also greater in myasthenics for 20° saccades; however, this difference did not reach statistical significance for patients with MG (547 ± 89.8 deg/seconds vs 477 ± 104.5 deg/seconds) (P = 0.14). The latency of participants with MG was not significantly different from those of age-matched healthy participants in 10° saccades but was significantly different for 20° saccades. There was no difference in amplitude measured between the groups. CONCLUSIONS PV for both 10 and 20° saccades was greater in myasthenic patients compared with healthy controls. All myasthenic patients produced normal velocity saccades in the presence of deficits of smooth ocular motility. The results from this small pilot study demonstrate the potential use of the saccadometer in a clinical setting to provide a noninvasive aid in the diagnosis of patients suspected with myasthenia.

To measure the Accommodative Convergence (PD)/Accommodation ratio (D) (AC/A) in a cohort of visually normal participants using common clinical methods.AC/A ratios of 50 visually normal subjects were measured using the distance gradient (DG), near gradient (NG), gradient using synoptophore, (SG) and heterophoria (H) methods in line with current clinical practice.Median AC/A ratios for NG, DG, SG, and H were 2.0 (IQR 2.0), 1.0 (IQR 0.6), 1.0 (IQR 0.6), and 5.0 (IQR 1.7), respectively. There was a statistically significant difference in ratios calculated between all methods in the same subjects (p 0.05). There were differences in DG vs NG, DG vs H, SG vs H, and NG vs H (p 0.05); only DG vs SG did not differ significantly (p 0.05). Lens power toleration was found to affect AC/A ratio in DG (p 0.05) and latent deviation was significantly associated with (p 0.05) AC/A ratio in NG.Calculated AC/A ratios in this cohort were lower than historically cited normal (3-5:1) in all gradient methods. There were differences in AC/A values in the same subjects calculated with different gradient methods, indicating that these methods are not interchangeable and a universal normal range should not be applied for all methods.

AimsThere is a paucity of literature concerning intractable diplopia. The aims of this study were to determine the incidence of intractable diplopia in the UK, identify the causes and any associated risk factors, establish how cases are managed and if the treatment is successful and tolerated.MethodsA 1-year prospective observational study was undertaken via the British Ophthalmological Surveillance Unit (BOSU). This involved implementation of a reporting mechanism, which then triggered distribution of an incident questionnaire to explore clinical details concerning each case and a follow-up questionnaire 6 months later to explore how the case had been managed.ResultsThe incidence of intractable diplopia was 53 cases per year. The most common preceding events were strabismus surgery (32%), no known preceding event, that is,spontaneous (25%), severe head trauma (8%), cataract surgery (6%) and vitrectomy (6%). In the at-risk age group of 7 years and above, the incidence of intractable diplopia following strabismus surgery is 1 in 494 (95% CI; 1 in 296 to 790) cases. A total of nine different treatments were used in the management, with many patients receiving between two and four different methods. The overall success rate was poor, but most effective were opaque intraocular lenses (IOLs) (86%) and opaque contact lenses (50%).ConclusionIntractable diplopia is a relatively rare but important condition. The main risk factor is a pre-existing strabismus, and careful counselling is needed when planning surgical correction in patients with no demonstrable binocular function. Treatment success of intractable diplopia is high when using opaque IOLs, although with additional risk, but is often disappointing via other methods where it can be difficult to eradicate the diplopia successfully.

Occlusion used to treat amblyopia towards the end of the developmental component of the critical period gives a risk of inducing intractable diplopia. In the United Kingdom, the density of suppression is assessed via the Sbisa/Bagolini filter bar, but there is very little research evidence to guide clinical practice or interpretation of the tests used. The aims of this study were to determine current practice and estimate the incidence of intractable diplopia following amblyopia treatment.Current practice and incidence of intractable diplopia following amblyopia were determined via a questionnaire distributed to head orthoptists in every eye department in the United Kingdom. The questionnaire explored testing and test conditions, interpretation of the test results, and cases of intractable diplopia over the last 5 years.There was considerable variation in clinical practice of the measurement of the density of suppression and interpretation of the results to guide the treatment of amblyopia. The minimum age of patients taking the test ranged from 2 to 8 years and the minimum filter considered still safe to continue treatment ranged from 4 to 17. It is estimated there were 24 cases of intractable diplopia over the last 5 years.The issue of intractable diplopia and amblyopia treatment is likely to become increasingly important as there appears to be greater plasticity and scope to treat amblyopia in teenagers and adults than was previously thought. Lack of knowledge of how to evaluate the risk may lead to more cases of intractable diplopia or alternatively treatment being withheld unnecessarily.

Purpose To determine the effect of changing illuminance on visual and stereo acuity. Methods Twenty-eight subjects aged 21 to 60 years were assessed. Monocular visual acuity (ETDRS) of emmetropic subjects was assessed under 15 different illuminance levels (50–8000 lux), provided by a computer controlled halogen lighting rig. Three levels of myopia (−0.50DS, −1.00DS & 1.50DS) were induced in each subject using lenses and visual acuity (VA) was retested under the same illuminance conditions. Stereoacuity (TNO) was assessed under the same levels of illuminance. Results A one log unit change in illuminance level (lx) results in a significant change of 0.060 LogMAR (p

Establish whether the Sbisa bar, Bagolini filter (BF) bar, and neutral density filter (NDF) bar, used to measure density of suppression, are equivalent and possess test-retest reliability. Determine whether density of suppression is altered when measurement equipment/testing conditions are changed.Our pilot study had 10 subjects aged ≥18 years with childhood-onset strabismus, no ocular pathologies, and no binocular vision when manifest. Density of suppression upon repeated testing, with clinic lights on/off, and using a full/reduced intensity light source, was investigated. Results were analysed for test-retest reliability, equivalence, and changes with alteration of testing conditions.Test-retest reliability issues were present for the BF bar (median 6 filter change from first to final test, p = 0.021) and NDF bar (median 5 filter change from first to final test, p = 0.002). Density of suppression was unaffected by environmental illumination or fixation light intensity variations. Density of suppression measurements were higher when measured with the NDF bar (e.g. NDF bar = 1.5, medium suppression, vs BF bar = 6.5, light suppression).Test-retest reliability issues may be present for the two filter bars currently still under manufacture. Changes in testing conditions do not significantly affect test results, provided the same filter bar is used consistently for testing. Further studies in children with strabismus having active amblyopia treatment would be of benefit. Despite extensive use of these tests in the UK, this is to our knowledge the first study evaluating filter bar equivalence/reliability.

Aims: To validate the design of updated optotypes to be used in the Kay picture acuity tests to improve the resolution acuity, recognition, repeatability and comparisons with gold standard logMAR acuity assessments. Methods: The study was completed in four phases. Inball phases the pictures were presented on a monitor as a single crowded optotype, with five optotypes at each visual acuity (VA) level. Phase one assessed the resolution acuity for 25 pictures, eight Landolt Csband five ETDRS letters. The recognition phase (phasebtwo) assessed children (18 months to 5 years) to determine which pictures were most commonly identified. During phase three, the resolution acuity of a reduced number of pictures and the Landolt C were reassessed to ensure that fatigue had not influenced the initial results. Phase four compared the new Kay pictures with LEA symbols and the ETDRS (part a), and repeatability of the Kay pictures and the ETDRS chart (part b). Results: 'Phase one (resolution acuity)': 50 adult subjects were tested. The mean (±SD) acuity scores achieved using each of the 25 pictures ranged from -0.123 ±0.124 to -0.308 ±0.105. The mean (±SD)bacuity for the eight Landolt C orientations was -0.059 ±0.120, and -0.128 ±0.101 for the ETDRS letters. Following this analysis, three pictures were removed. Phase two (Recognition): 420 children were assessed (54% male) using the remaining 22 pictures. Analysis resulted in the removal of 10 pictures based on the recognition levels. Phase three (resolution acuity): 43 adult subjects were tested with the remaining 12 pictures. The picture selection was reduced to six based on a combination of similar mean bias levels, recognition levels in all children and recognition levels in the youngest children. Phase four (a) (comparability): 113 adult subjects were tested. The mean bias indicated similar results between the tests. The limits of agreement for ETDRS versus Lea symbols were slightly wider than for ETDRS versus Kay pictures. Phase four (b) (repeatability): 100 adult subjects were tested. Paired 't'-test analysis demonstrated no significant difference between tests in either ETDRS ( p = 0.1) or Kay pictures ( p = 0.1). Mean bias for both tests was 0.01 logMAR with similar limits of agreement. Conclusion: The newly designed Kay picture optotypes have been shown to be reliably recognised by a paediatric population. In a six-picture test format the newly designed optotypes with single picture presentation and crowding bars have been shown to be a reliable and repeatable VA test in an adult population with good agreement with current gold standard VA assessment methods. Normative data in a paediatric population are now required.