Effect Of Prolonged Monocular Occlusion On Latent Nystagms

The authors recorded nystagmus during seeing with one eye in eight patients with latent nystagmus (LN) before and after two or three days of prolonged occlusion of the better eye (POBE). Before POBE, the slow-phase speed of the nystagmus (SPS) was usually higher when the better eye was covered. After POBE, the SPS during cover of the better eye had decreased and the SPS during cover of the poorer eye had increased (please note the time difference between ‘prolonged occlusion’ and ‘cover'). However, the sum of the two speeds (absolute values, for they were opposite in direction) remained the same in all cases. This indicates that the principal component of the LN, the difference between LN with right-and LN with left-eye cover, remained the same, but a drift towards the poorer eye had been added that decreased the SPS during cover of the better eye and increased the SPS during cover of the poorer eye. In three patients who had oscillopsia during POBE, the oscillopsia gradually decreased over days during POBE, indicating that the drift changes slowly, over a period of days. As regards occlusion therapy in children with amblyopia and latent nystagmus, based on these findings, it seems advisable to occlude the better eye during days per week, rather than during hours per day: Then there is more time for the nystagmus to decrease, so that amblyopia therapy can be more effective

In Graves' disease, increased muscle tension and reduced elasticity of affected muscles is primarily caused by active muscle contraction

In three patients with Graves' disease of recent onset, length-tension diagrams were made during surgery for squint under eyedrop anesthesia, while the other eye looked ahead, into the field of action, or out of the field of action of the muscle that was measured. The affected muscles were found to be very stiff when the other eye looked straight ahead. Unexpectedly, the affected muscle did not shorten any further (one case) or only 6-7 mm (two cases) when the other eye looked into the field of action of the muscle, whereas it lengthened 9-10 mm when the other eye looked out of the field of action of the muscle. This means that the raised muscle tension and reduced elasticity of affected muscles in these cases of Graves' disease of recent onset are caused by active muscle contraction. It has been found previously that hyperthyroidism, induced in rats, casues transitions from slower to faster myosin-heavy chain (MHC) types. The findings seem compatible with a transition of slow into fast muscle fiber types in Graves' disease

Increased muscle tension and reduced elasticity of affected muscles in recent-onset Graves' disease caused primarily by active muscle contraction

In 3 patients with Graves' disease of recent onset, length-tension diagrams were made during surgery for squint under eyedrop anesthesia. The affected muscles were found to be very stiff when the other eye looked straight ahead. It was expected that these stiff muscles would be able to shorten to some extent but would be unable to lengthen, due to fibrosis of the muscle. We found that the affected muscles did not shorten very much when the other eye looked into the field of action of the muscle. Unexpectedly however, they lengthenend considerably when the other eye looked out of the field of action of the muscle. This finding implies that the raised muscle tension and reduced elasticity of affected muscles in these cases of Graves' disease of recent onset were primarily caused by active muscle contraction, not by fibrosis

Making room for manoeuvre: addressing gender norms to strengthen the enabling environment for agricultural innovation

Local gender norms constitute a critical component of the enabling (or disabling) environment for improved agricultural livelihoods – alongside policies, markets, and other institutional dimensions. Yet, they have been largely ignored in agricultural research for development. This viewpoint is based on many years of experience, including a recent major comparative research initiative, GENNOVATE, on how gender norms and agency interact to shape agricultural change at local levels. The evidence suggests that approaches which engage with normative dimensions of agricultural development and challenge underlying structures of inequality, are required to generate lasting genderequitable development in agriculture and natural resource management

Force-length recording of eye muscles during local-anesthesia surgery in 32 strabismus patients

Abstract. Force-length recordings were made from isolated human eye muscles during strabismus surgery in local, eye-drop anesthesia in 32 adult patients. From each muscle three recordings were made: (1) while the patient looked with the other eye into the field of action of the recorded muscle, (2) looked ahead, and (3) looked out of the field of action of the recorded muscle. Non-innervated eye muscles (state 3) had an approximately exponential relation between force and length. During contraction evoked by letting the patient look ahead or into the field of action of the muscle (states I or 2), the relation between force and length was grossly linear. The approximate spring constants of horizontal rectus muscles that had not been operated on before ranged from 2 to 4 g/mm. In palsies, the degree of muscle paresis could be quantified accurately using this method and, accordingly, cases of true superior oblique palsy could be well differentiated from strabismus sursoadductorius (= upshoot in adduction) that may mimic a superior oblique palsy. In seven patients with Graves' disease of recent onset, affected muscles were found to be very stiff when the other eye looked ahead. It was expected that these stiff muscles would be able to shorten to some extent but would not be able to lengthen, due to fibrosis of the muscle. We found, however, that the affected muscles lengthened considerably when the other eye looked out of the field of action of the muscle. This implies that, in these cases of Graves' disease of recent onset, the raised muscle tension and reduced elasticity of the affected muscles and, hence, the strabismus were primarily caused by active muscle contraction, not by fibrosis

Genetic mitigation strategies to tackle agricultural GHG emissions: The case for biological nitrification inhibition technology

Accelerated soil-nitrifier activity and rapid nitrification are the cause of declining nitrogen-use efficiency (NUE) and enhanced nitrous oxide (N2O) emissions from farming. Biological nitrification inhibition (BNI) is the ability of certain plant roots to suppress soil-nitrifier activity through production and release of nitrification inhibitors. The power of phytochemicals with BNI-function needs to be harnessed to control soil-nitrifier activity and improve nitrogen-cycling in agricultural systems. Transformative biological technologies designed for genetic mitigation are needed so that BNIenabled crop-livestock and cropping systems can rein in soil-nitrifier activity to help reduce greenhouse gas (GHG) emissions and globally make farming nitrogen efficient and less harmful to environment. This will reinforce the adaptation or mitigation impact of other climate-smart agriculture technologies

Endophthalmitis after strabismus surgery: incidence and outcome in relation to age, operated eye muscle, surgical technique, scleral perforation and immune state

Purpose: Identify risk factors for endophthalmitis after strabismus surgery (EASS) and relate these to incidence and outcome. Methods: Ophthalmologists, who had operated, diagnosed or treated EASS, completed a case record form with 71 questions in six domains: Preoperative, Surgery, Perforation, Postoperative, Outcome and Experts’ opinion. To estimate the age-specific incidence per number of strabismus operations in the Netherlands during 1994-2013, the age distribution of Dutch cases was compared with the age-specific rates of strabismus surgery in the Dutch Registry of Strabismus Operations and with population data. Exploratory data analysis was performed. The immune state was evaluated in six patients. Five enucleated eyes were studied histopathologically. Results: None of the 26 patients (27 eyes with EASS) were between 9 and 65 years old, except for one patient with retinal haemorrhage followed by endophthalmitis. In the Netherlands during 1994-2013, the rate of EASS was approximately one per 11 000 strabismus operations, but one per 4300 for children aged 0–3 and one per 1000 for patients 65 and older. Endophthalmitis was diagnosed on postoperative day 1–4 in children aged 0–3. In all 15 children aged 0–5, the 16 affected eyes were phthisical, eviscerated or enucleated. The involved eye muscle had been recessed in 25 of 27 cases. It was a medial rectus in 15 of 16 children aged 0–6. It was a lateral (6), inferior (2) or medial (1) rectus in elderly. Scleral perforation went unnoticed in all children (no record in three) and in two of seven elderly (no record in two). Histopathology showed transscleral scarring compatible with scleral perforation in four patients but, in a two-year-old girl who had EASS together with a transient medial rectus palsy, the sclera underneath the former suture tract was not perforated but did contain the long posterior ciliary artery. Conclusions: Endophthalmitis after strabismus surgery (EASS) affects children and elderly, with a grave outcome in young children. It occurs after recession of the medial rectus muscle in children, and it may occur without scleral perforation. Age and perforation influence many other parameters that determine the occurrence and fulminance of EASS

Management of nystagmus in children: A review of the literature and current practice in UK specialist services

Nystagmus is an eye movement disorder characterised by abnormal, involuntary rhythmic oscillations of one or both eyes, initiated by a slow phase. It is not uncommon in the UK and regularly seen in paediatric ophthalmology and adult general/strabismus clinics. In some cases, it occurs in isolation, and in others, it occurs as part of a multisystem disorder, severe visual impairment or neurological disorder. Similarly, in some cases, visual acuity can be normal and in others can be severely degraded. Furthermore, the impact on vision goes well beyond static acuity alone, is rarely measured and may vary on a minute-to-minute, day-to-day or month-to-month basis. For these reasons, management of children with nystagmus in the UK is varied, and patients report hugely different experiences and investigations. In this review, we hope to shine a light on the current management of children with nystagmus across five specialist centres in the UK in order to present, for the first time, a consensus on investigation and clinical management

Mobius Syndrome, A Surprise

Eyestrain; HeadacheA 25-year old male with eyestrain and tension headache. Previous history significant for esotropia.N/AN/ASpongioblastomaN/AN/