P. Eustace

Absent meibomian glands: A marker for EEC syndrome

A patient with a 20 year history of severe keratoconjunctivitis of unknown origin was found, on assessment at a blepharitis clinic, to have complete absence of meibomian glands. Further examination revealed the features of EEC syndrome. To our knowledge, this is the only case to have been diagnosed in this way. The ocular complications of EEC syndrome and other ectodermal dysplasias are reviewed.

Clinical comparison of three techniques for evaluating visual function behind cataract

The aim of the study was to compare the ability of displacement threshold hyperacuity to identify reduced retinal/neural function in cataract patients with that of the potential acuity meter (PAM) and laser interferometer. Fifty-two patients (mean age 72.0 ± 10.8 years) admitted for extracapsular cataract extraction were randomly selected for inclusion in the study. Patients underwent routine refraction and logMAR acuity measurement on the eve of cataract surgery. Following pupillary dilation and in random order, the oscillatory displacement threshold (ODT; defined as the smallest detectable displacement of an object) was determined, and predictions of the post-operative acuity were obtained using the PAM and Rodenstock Retinometer (RR). Patients were re-examined approximately 7 weeks post-operatively when logMAR acuities and ODTs were remeasured. On the basis of the results of an independent fundus examination, patients were assigned to either a normal or a pathology group. Increasing cataract density adversely affected the predictions provided by the PAM (p = 0.0001) and ODT (p = 0.0001) techniques, but not the RR (p = 0.137). One-factor ANOVA revealed that pre-operative ODT (p = 0.0001), PAM (p = 0.0001) and RR (p = 0.0004) measures successfully distinguished patients with retinal/neural pathology from normals. Pre-operative cut-off levels to distinguish normal from pathology cases were retrospectively determined for each technique. The cut-off values for the PAM and ODT techniques yielded higher sensitivity and specificity values than was the case for the RR. The results suggest that the predictive abilities of the PAM and ODT techniques are similar, and superior to that of the RR. Further work involving larger numbers of patients with posterior segment pathology is necessary to reveal which technique provides the best means of assessing retinal/neural function in the presence of ocular media opacities.

Effects of posterior segment disorders on oscillatory displacement thresholds, and on acuities as measured using the Potential Acuity Meter and laser interferometer

Oscillatory displacement thresholds (ODTs) were measured in 67 subjects with clear ocular media, but known posterior segment disorders. The ability of these thresholds to assess reduced visual function, as quantified by visual acuity deficits, was compared with that of the Potential Acuity Meter (PAM) and the Rodenstock Retinometer (RR). ODTs were found to be sensitive to acuity deficits which were retinal/neural in origin. Despite the fact that interferometric acuities are, unlike ODTs, a measure of resolution, the RR proved no more accurate in assessing the level of letter acuity which existed than did ODT measurement. As would be expected, the PAM provided for the most accurate means of assessing non‐optical visual acuity deficits. However, the PAM proved lo be less useful in eyes with: very poor levels of acuity, and certain anomalous conditions. The results have implications for the relative ability of each of the three tests to identify reduced visual function behind cataract.

Hypertensive Retinopathy: A Cause of Decreased Visual Acuity in Children

Hypertensive retinopathy may present atypically in children. Delays in diagnosis may result in permanent visual loss, as demonstrated in three cases we saw.

Dark Adaptation in Disabled Readers Screened for Scotopic Sensitivity Syndrome

A peripheral retina, photoreceptor, or transient visual-system deficit has been suggested as a basis for dyslexia. We performed dark adaptation using a Goldmann-Weekers adaptometer on 41 dyslexic readers subjected to the Irlen Differential Perceptual Schedule for the Scotopic Sensitivity Syndrome and on 23 volunteers of normal reading ability, all aged between 10 and 20 years. 12 of the 41 disabled readers examined had abnormally poor dark adaptation at peripheral retinal locations consistent with a rod processing-system deficit.

Partial nuclear third nerve palsies

Subnuclear lesions of the third nerve nuclear complex may present with loss of elevation in one eye with contralateral loss of depression. Two patients with these signs are presented.

Congenital ocular motor apraxia: An inability to unlock the vestibulo-ocular reflex

The authors report ten cases of congenital ocular motor apraxia. Two patients had Cockaynes syndrome. One patient had succinic semialdehyde dehydrogenase deficiency. One patient had vermian hypoplasia of the cerebellum. Four patients had precocious head movements with abnormal limb tremor in the first two days of life.Based on their findings the authors postulate that head thrusts are the result of a failure to unlock the vestibulo-ocular reflex from the object of regard rather than a strategy to assist horizontal gaze.

Assessing retinal/neural function in patients with cataract using oscillatory displacement thresholds.

Oscillatory displacement threshold (ODT) measurement has been proposed as a useful means of assessing retinal/neural function behind cataract. In order to examine the qualitative predictive ability of this technique, the influence of age, simulated cataract, and various posterior segment disorders upon ODTs were investigated. In a separate investigation, thresholds were measured in 30 cataract patients on the eve of surgery, and again 6 to 8 weeks postoperatively. ODTs were found to increase with age (p < 0.001) and were highly resistant to the effects of image degradation as produced by simulated cataract. In addition, thresholds were sensitive to the presence of retinal/neural disorders (p << 0.001). Although not completely independent of the presence of cataract, higher ODTs were measured in cataract patients with coexistent retinal/neural dysfunction than was the case for patients with normal posterior segments (p < 0.001). Preoperative ODT measurement may offer a means of distinguishing between the optical and retinal/neural components of visual impairment in patients with cataract.

The pattern of perforating eye injuries in Ireland

BackgroundAlmost all perforating eye injuries present to dedicated eye units. Data from eye units are therefore reliable indicators of the incidence of perforating injuries.AimsTo establish the aetiology and visual outcome of perforating eye injuries presenting to one unit over a twelve-month period.MethodsPatients with eye injury were identified from the operating room register. Case-notes were reviewed and eye examinations were performed to determine current level of vision.ResultsA total of 37 perforating eye injuries were operated on in the 12-month period from January to December 1995. Thirty one patients (83.8%) were male. The mean age was 33.9 years. The chief causes were work related or do-it-yourself (DIY) in 32.4%, miscellaneous accidents in 27.0%, assault in 16.2%, road traffic accidents in 10.8%. Twenty eyes (54.1%) were blind with acuity <6/60 at their most recent review.ConclusionWork-related and DIY injuries are the most common causes of eye perforation. Many of these injuries are easily preventable with appropriate eye protection. The proportion of injuries resulting from road traffic accidents was low. Injuries due to assault are becoming more prevalent and carry a poor visual prognosis.

One-and-a-half syndrome following intravenous morphine injection in a drug user

A 25-year-old man presented with a history of headache; dizziness and diplopia after intravenous injection of dissolved morphine sulphate tablets. He had no other symptoms of cerebellar or brainstem dysfunction. On examination, a left one-and-a-half syndrome, right paralytic pontine exotropia and left partial lower facial nerve palsy were found. Radiological examination with M.R.I, brain scan showed a pontine infarct at the level of the facial and auditory nerve complex. Gradual recovery after dexamethasone therapy.