Ophthalmological manifestations of multiple sclerosis

Optic neuritis, as a result of the formation of demyelination plaques in the optic nerve, is one of the commonest early symptoms of multiple sclerosis. Hence, it is important that optometrists are aware of the symptoms of optic neuritis and of the conditions with which it can be confused. However, only a proportion of patients with optic neuritis will develop the symptoms of multiple sclerosis. The first part of the article describes the symptoms and differential diagnosis of optic neuritis and its relationship with multiple sclerosis. In the second part of the article, the variety of visual changes and symptoms which can be observed in multiple sclerosis patients will be described.

AIDS: neurological and ophthalmological aspects

Although overt ocular symptoms are not often encountered in AIDS patients, many exhibit subtile neuro-ophthalmic signs and symptoms. This article describes the neuropsychiatric symptoms as well as the neuro-ophthalmic conditions which have been reported recently in AIDS patients. The degree to which optometrists may be vulnerable to the AIDS virus from contact with patients in practice will also be discussed.

Assessing visual fields for driving in patients with paracentral scotomata

Background: The binocular Esterman visual field test (EVFT) is the current visual field test for driving in the UK. Merging of monocular field tests (Integrated Visual Field, IVF) has been proposed as an alternative for glaucoma patients. Aims: To examine the level of agreement between the EVFT and IVF for patients with binocular paracentral scotomata, caused by either ophthalmological or neurological conditions, and to compare outcomes with useful field of view (UFOV) performance, a test of visual attention thought to be important in driving. Methods: 60 patients with binocular paracentral scotomata but normal visual acuity (VA) were recruited prospectively. Subjects completed and were classified as “pass” or “fail” for the EVFT, IVF and UFOV. Results: Good agreement occurred between the EVFT and IVF in classifying subjects as “pass” or “fail” (kappa?=?0.84). Classifications disagreed for four subjects with paracentral scotomata of neurological origin (three “passed” IVF yet “failed” EVFT). Mean UFOV scores did not differ between those who “passed” and those who “failed” both visual field tests (p?=?0.11). Agreement between the visual field tests and UFOV was limited (EVFT kappa?=?0.22, IVF kappa 0.32). Conclusions: Although the IVF and EVFT agree well in classifying visual fields with regard to legal fitness to drive in the UK, the IVF “passes” some individuals currently classed as unfit to drive due to paracentral scotomata of non-glaucomatous origin. The suitability of the UFOV for assessing crash risk in those with visual field loss is questionable.

How accurate are photographic surrogate markers used to detect macular edema in the English national screening programme?

DESIGN. Retrospective analysis PURPOSE. Macular oedema is not directly visible on two dimensional digital photographs such that surrogate markers need to be used. In the English National Screening Programme these are exudate within one optic disc diameter (DD) of the fovea, group of exudates within two DD of the fovea and haemorrhages or microaneurysms (HMA) within one DD of the fovea with best corrected visual acuity (VA) worse than 6/9. All patients who present with any of these surrogate markers at screening are referred to an ophthalmology clinic for slit lamp examination. The purpose of this audit was to determine how many patients with positive maculopathy diagnosis on photography were truly identified by optical coherence tomography (OCT) with macular oedema. METHODS. Data was collected from patients attending digital diabetic retinopathy screening. Patients who presented with surrogate markers for macular oedema also had an OCT scan. The fast macula scan on the Stratus OCT was used and an ophthalmologist reviewed the scans to determine whether macular oedema was present. RESULTS. Maculopathy by exudates: Of 155 patients 45 (29%) showed thickening on the OCT of these 12 required laser. Those who also had pre-proliferative retinopathy (n=20) were more likely to have macular oedema (75%) than those with background diabetic retinopathy. Maculopathy by HMA and VA worse than 6/9: Of 66 patients 11 (16.7%) showed thickening on the OCT. 5 (7.6%) of these had macular oedema, 5 (7.6%) epi-retinal membrane, and 1 (1.5%) age related macular degeneration. None of these patients required laser. CONCLUSIONS. The likelihood of the presence of macular oedema and requiring laser treatment is greater with macular exudation than HMA within one DD and reduced VA. Overall the surrogate markers used show low specificity for macular oedema, however combining OCT with photography does identify those with macular oedema who require a true referral for an ophthalmological slit lamp examination.

The management of ocular allergy in community pharmacies in the United Kingdom

Background Ocular allergies frequently present in pharmacy practices. However, research into the actual management of ocular allergy in pharmacies is lacking. Objective To determine and quantify history and symptom questioning of a patient with presumed allergic conjunctivitis and management strategies employed by pharmacy staff in the UK. Method A mystery shopper technique was used to simulate an episode of allergic conjunctivitis in 100 community pharmacies across the UK. Results The mean number of questions asked by pharmacy staff to the patient was 3.5 ± 2.6, with a range of 0-10. The most common question was whether the patient had a history of allergies (45 %).Ninety-one percent advised on treatment, with the remaining 9 % directly referring to the patient's general practitioner (n = 4) or pharmacist(n = 4), but only two to their optometrist. The most common treatment suggested was sodium cromoglycate 2 % (50 %). However, many pharmacies advising treatment did not ask the patient's age (37 %), if they wore contact lenses (43 %), or gave dosage advice (43 %). Only 5 % of pharmacies advised follow up and 14 % suggested visiting a general practitioner and 1 % an optometrist if symptoms did not resolve with treatment. Conclusion There is a need for improved ophthalmological training for pharmacy staff with respect to the management of allergic conjunctivitis. © Springer Science+Business Media Dordrecht 2012.

Management of dry eye in UK pharmacies

Purpose - To investigate the ability of pharmacy staff in the United Kingdom (UK) to diagnose and treat dry eye. Methods - A mystery shopper technique to simulate a patient with presumed dry eye was used in 50 pharmacy practices in major towns and cities across the UK. Pharmacies were unaware of their involvement in the study. With the exception of a predetermined opening statement to initiate the consultation, no further information was volunteered. Questions asked, diagnoses given, management strategy advised and staff type was recorded immediately after the consultation. Results - The mean number of questions was 4.5 (SD 1.7; range 1–10). The most common question was the duration of symptoms (56%) and the least common was whether the patient had a history of headaches (2%). All pharmacy staff gave a diagnosis, but the majority were incorrect (58%), with only 42% correctly identifying dry eye. Treatment was advised by 92% of pharmacy staff, with the remaining 8% advising referral directly to the patient's GP or optometrist. Dry eye treatments involved topical ocular lubrication via eye drops (90%) and lipid based sprays (10%). However, only 10% gave administration advice, 10% gave dosage advice, 9% asked about contact lens wear, and none offered follow up although 15% also advised GP or optometrist referral. Conclusions - There is a need for improved ophthalmological training amongst pharmacists and pharmacy staff and establishment of cross referral relationships between pharmacies and optometry practices.

Evaluating techniques to improve visual performance with and assessment of premium intraocular lenses

Premium Intraocular Lenses (IOLs) such as toric IOLs, multifocal IOLs (MIOLs) and accommodating IOLs (AIOLs) can provide better refractive and visual outcomes compared to standard monofocal designs, leading to greater levels of post-operative spectacle independence. The principal theme of this thesis relates to the development of new assessment techniques that can help to improve future premium IOL design. IOLs designed to correct astigmatism form the focus of the first part of the thesis. A novel toric IOL design was devised to decrease the effect of toric rotation on patient visual acuity, but found to have neither a beneficial or detrimental impact on visual acuity retention. IOL tilt, like rotation, may curtail visual performance; however current IOL tilt measurement techniques require the use of specialist equipment not readily available in most ophthalmological clinics. Thus a new idea that applied Pythagoras’s theory to digital images of IOL optic symmetricality in order to calculate tilt was proposed, and shown to be both accurate and highly repeatable. A literature review revealed little information on the relationship between IOL tilt, decentration and rotation and so this was examined. A poor correlation between these factors was found, indicating they occur independently of each other. Next, presbyopia correcting IOLs were investigated. The light distribution of different MIOLs and an AIOL was assessed using perimetry, to establish whether this could be used to inform optimal IOL design. Anticipated differences in threshold sensitivity between IOLs were not however found, thus perimetry was concluded to be ineffective in mapping retinal projection of blur. The observed difference between subjective and objective measures of accommodation, arising from the influence of pseudoaccommodative factors, was explored next to establish how much additional objective power would be required to restore the eye’s focus with AIOLs. Blur tolerance was found to be the key contributor to the ocular depth of focus, with an approximate dioptric influence of 0.60D. Our understanding of MIOLs may be limited by the need for subjective defocus curves, which are lengthy and do not permit important additional measures to be undertaken. The use of aberrometry to provide faster objective defocus curves was examined. Although subjective and objective measures related well, the peaks of the MIOL defocus curve profile were not evident with objective prediction of acuity, indicating a need for further refinement of visual quality metrics based on ocular aberrations. The experiments detailed in the thesis evaluate methods to improve visual performance with toric IOLs. They also investigate new techniques to allow more rapid post-operative assessment of premium IOLs, which could allow greater insights to be obtained into several aspects of visual quality, in order to optimise future IOL design and ultimately enhance patient satisfaction.

Is it safe to increase diabetic retinopathy screening intervals in patients with no background diabetic retinopathy?

Introduction. A 4 year retrospective follow up of 996 patients who pre-sented with no DR and 500 with background DR at baseline digital DR screening in 2006. Purpose. To evaluate the safety of increasing screening intervals in patients with no diabetic retinopathy (DR) or with background DR.Methods. A 4 year retrospective follow up of 996 patients who presented with no DR and 500 with background DR at baseline digital DR screening in 2006.results. Background DR Group: Of the 500 subjects that had back-ground DR in 2006, 231 were referred for DR, with an average DR routine referral rate of 12% (46 subjects) per year. nodrgrouP. Of the 996 patients who had no DR at baseline, 51 were referred over the 4 years for sight threatening DR (STDR), of these 45 patients have definite STDR confirmed by ophthalmological examination. 78% of these had type 2 diabetes and mean age at referral was 60 years (25-87). Mean diabetes duration was 10.7 years (3-32), with a mean HbA1c of 7.8% (5.7-11.3%). Eight patients (0.9%) were referred in the first year, 9 (0.9%) in the second year, 19 (1.9%) in the third year and 15 (1.5%) in the fourth year. 86% of referrals were for maculopathy, and all had observable retinopathy and none required ophthalmology clinic assessment or laser treatment.If biannual screening was adopted for patients with no DR at baseline, allowing for patients who subsequently develop background DR and would then revert to annual screening, a total of 7 (0.7%) patients would not have been appropriately referred for STDR and would have waited a further year for identification. None of the 51 referrals across the 4 years required laser treatment apart from just one patient who developed PDR in year 4 (2010) and had background since 2007.conclusIons. It could be recommended that it is safe to screen pa-tients with no DR biannually due to the low risk of developing STDR. However, patients who present with background DR should continue to be screened annually as there is a significant proportion developing STDR and would not be identified at an appropriate screening interval.