bluuebunny/crossref_metadata_2025_split huggingface dataset:
Barrier activity of fractionated human serum
Authors: Langford‐Smith J , Gillies M , Billson F 
Published: November 2007

ABSTRACTPurpose:Breakdown of the blood‐retinal barrier is a major cause of visual loss in diseases such as diabetic retinopathy, age‐related macular degeneration and retinal vein occlusion.Methods:Human serum, fractionated by gel filtration, was screened for factors that enhance barrier activity by measuring electrical resistance across monolayers of human umbilical vein endothelial cells.Results:Two peaks of barrier‐enhancing activity were detected. The larger peak was broad, contained a preponderance of albumin and increased barrier activity to 183% of controls. The barrier‐enhancing properties of the larger peak, however, appeared to be associated with proteins in general and not just albumin. The fractions associated with elution of the larger peak induced maximal increase in resistance in under I h, relative to controls. The smaller peak was associated with molecular weights much smaller than those of proteins.
A multiple‐frequency, multiple‐region pattern electroretinogram investigation of non‐linear retinal signals
Authors: Maddess T , Bedford S , James AC , Rose KA 
Published: November 2007

ABSTRACTIt has been proposed that the spatial frequency doubled (FD) illusion may originate from Y‐like non‐linear retinal ganglion cells. If the contrast of multi‐frequency stimuli is increased, Y cells show a phase advance in the self‐sum frequencies but not in other output frequencies. We looked for these effects with a multi‐region pattern electroretinogram (PER.G) displaying the sum of two temporal frequencies in each visual field location. Regional variation was found in the recorded sum and difference frequencies. The results indicate that PERG signals become dominated by responses from Y‐like cells when the FD illusion is seen.
Development of spatial resolution, contrast sensitivity and binocularity in normal and strabismic kittens
Authors: Li XR , Crewther SG , Westbrook A , Crewther DP 
Published: November 2007

ABSTRACTThe purpose of the present experiment was to evaluate visual acuity, contrast sensitivity and binocularity in teno‐tomized, strabismic kittens of various ages.
Postoperative suture manipulation for control of corneal graft astigmatism
Authors: Hirst Lawrence W , McCoombes John A , Reedy Manjula 
Published: November 2007

Abstract Purpose: To assess the effect on post‐keratoplasty astigmatism of postoperative manipulation of a single running suture. Methods: All corneal transplant patients in whom a single 10/0 nylon running suture was placed between November 1990 and April 1996 were included in a prospective study of the effect of manipulation of the suture at the earliest possible time after surgery when the keratometry became possible by virtue of the epithelial surface integrity and where this revealed astigmatism of greater than 2 D. Results: One hundred and ninety eyes underwent suture manipulation and were followed up. Follow up on 30 eyes was discontinued. Repeat manipulation of the running suture was the most common reason for discontinuation of follow up. The remaining patients were followed for a mean (± SD) 415.5 ± 326.4 days. Mean astigmatism of 7.8 ± 3.1 D was reduced to 1.7 ± 2.0 D immediately after manipulation, but regressed to 3.0 ± 1.9 D (n= 76) by 1 year. The suture was removed in 32 patients. Twenty‐five eyes had post‐removal astigmatism measurements. In these 25 eyes, astigmatic error appeared not to revert to premanipulation levels. The only significant complication was one broken suture at manipulation. Conclusions: Early suture manipulation is effective in reducing suture in post‐keratoplasty astigmatism, but some regression is seen.
Lacrimal canalicular obstruction associated with topical ocular medication
Authors: McNab Alan A 
Published: November 2007

Abstract Purpose: To describe the association between the use of various types of topical ocular medications and acquired lacrimal canalicular obstruction in 14 patients. Methods: The records of all patients in the author's practice with either lacrimal canalicular or punctal occlusion associated with the use of topical ocular medication were reviewed. Results: Fourteen cases were identified. The obstructions occurred at any point from the punctum to the common canaliculus, but most commonly occurred 2–5 mm from the lacrimal punctum. There was an association with various degrees of clinically apparent subconjunctival scaring maximal at the inner canthus, rarely to a severe degree, with symblepharon, medial canthal keratinization and cicatricial medial entropion. In some cases, no subconjunctival scarring could be clinically detected. Topical medications used were often multiple and included prednisolone acetate/phenylephrine hydrochloride (n= 5), timolol maleate (n= 5), pilocarpine (n= 3), dipivefrine hydrochloride or adrenaline (n= 3), chloramphenicol (n= 3), tobramycin (n= 3), indomethacin (n= 2), ecothiopate iodide (n= 1), betaxolol (n= 1), dexamethasone (n= 1), tropicamide (n= 1) and the long‐term use of naphazoline and various artificial tear preparations (n= 1). The duration of exposure ranged from 3 weeks to 20 years, with seven patients having used drops for 3–6 weeks. Seven patients had surgical repair, three by dacryocystorhinostomy (DCR) and glass by‐pass tube (all successful), three by canalicular repairs (one failed) and one by DCR and canalicular repair that restenosed at the puncta, who then had successful punctoplasty and silicone intubation. Conclusions: Lacrimal canalicular obstruction may occur after relatively short‐term exposure to topical ocular medications or as part of a more widespread cicatricial reaction in patients on long‐term medication. While a direct causal relationship cannot be confirmed, there appears to be a strong association and the site of the obstructions makes other causes unlikely.
Technetium‐99m (V) dimercaptosuccinic acid uptake by choroidal melanoma before and after iodine‐ 125 brachytherapy
Authors: Kiratli Hayyam , Kiratli Pinar Özgen , Ercan Meral Tayan , Bilgiç Sevgül 
Published: November 2007

Abstract Purpose: The value of the new tumour‐seeking agent technetium‐99m (V) dimercaptosuccinic acid (99mTc (V) DMSA), is assessed by the visualization of choroidal melanoma before and after iodine‐ 125 episcleral plaque brachytherapy. Methods: A prospective study was conducted on 12 consecutive patients with choroidal melanoma that was to be treated with plaque brachytherapy. The pre‐operative mean (± SD) maximal tumour basal diameter was 12.9 ± 2.9 mm and the mean tumour height was 8.2 ± 2.9 mm. Each patient had planar scintigraphy and single‐photon emission computed tomography using 99mTc (V) DMSA 2 days before treatment and 8 months following plaque removal. The calculated tumour to background ratios of these two tests were compared. Results: The pre‐operative tumour to background ratio was 1.8 ± 0.4 and all tumours could be correctly identified. At the time of postoperative imaging, all melanomas showed varying degrees of regression. The mean tumour height was 4.4 ± 2.1 mm. The tumour to background ratio was 1.4 ± 0.3. The difference between the two scintigraphic results was statistically significant (P= 0.002). Conclusions: Technetium‐99m (V) DMSA scintigraphy can accurately detect choroidal melanoma and document tumour response following episcleral radioactive plaque therapy. As such, this test can be an alternative ancillary investigative tool in the rare event of opaque media or diagnostic uncertainty.
Lipaemia retinalis
Authors: El‐Harazi Sherif M , Kellaway Judianne , Arora Anil 
Published: November 2007

Abstract Purpose: To present a patient with the rare condition of lipaemia retinalis and discuss the clinical features of this condition and its association with elevated triglyceride levels. Methods: Clinical evaluation of the patient, including fundus photographs before and after the initiation of a low fat diet, was undertaken. Results: Lowering of serum triglyceride and cholesterol levels was associated with complete resolution of the clinical picture of lipaemia retinalis. Conclusions: Lipaemia retinalis is a rare condition that is related to markedly elevated triglyceride levels. Lowering triglycerides levels leads to resolution of the clinical picture of this disease.
Persistent infra‐orbital nerve hyperaesthesia after blunt orbital trauma
Authors: Tengtrisorn Supaporn , McNab Alan A , Elder James E 
Published: November 2007

Abstract Background: Hyperaesthesia involving the infra‐orbital nerve is rarely associated with orbital floor fracture. Methods: An 11‐year‐old boy and a 34‐year‐old man had persistent and severe hyperaesthesia in the distribution of the infra‐orbital nerve 12 and 26 months, respectively, after blunt orbital trauma. Results: Surgical decompression of the infra‐orbital nerve resulted in rapid and complete resolution of the hyperaesthesia in both cases. Conclusion: Persistent hyperaesthesia of the infra‐orbital nerve is another indication for exploration of the orbital floor following blunt orbital trauma.
Combined astigmatic keratotomy with corneal valvular incision in the treatment of high surgical astigmatism
Authors: Dada T , Tityal JS , Sharma N 
Published: November 2007

Abstract Background: Astigmatic keratotomy is used conventionally to correct moderate surgical astigmatism. However, cases with very high surgical astigmatism due to wound compression can show a dramatic response to relaxing keratotomies made in the steeper meridian. The effect obtained cannot be predicted pre‐operatively by using standard nomograms. Methods: Coupled arcuate keratotomies combined with corneal valvular incisions were performed in a case of high astigmatism post‐cataract surgery. Results/Conclusion: Coupled arcuate keratotomies were combined with a corneal valvular incision enabled a surgical correction of nearly 9 D of astigmatism.
Pterygium surgery in Victoria: A survey of ophthalmologists
Authors: Snibson Grant R , Luu Chi D , Taylor Hugh R 
Published: November 2007

Abstract Aim: To determine the surgical approaches and adjunctive therapies currently used by Victorian ophthalmologists for the treatment of primary and recurrent pterygia. Method: Ophthalmologists practising in Victoria were asked to complete a written survey relating to their experience with pterygium surgery. Results: Responses were received from 142 of 165 ophthalmologists surveyed (86%). Of these, 107 (75%) had performed at least one pterygium operation during the preceding 2 years. Excision followed by beta irradiation was the most commonly performed procedure for both primary (57%) and recurrent (35%) pterygia. The next most commonly performed procedure for primary pterygia was excision leaving bare sclera (15%) and, for recurrent pterygia, excision with autologous conjunctival transplantation (26%). Considerable variation was observed in surgical technique, choice of adjunctive therapy, postoperative care and in the surgeons' estimates of the frequency of major complications. Conclusion: Although there is little consensus regarding the surgical management of pterygium, beta irradiation remains the most commonly used adjunctive therapy in Victoria.
Adjunctive intra‐operative local anaesthesia in paediatric strabismus surgery: A randomized controlled trial
Authors: Carden Susan M , Colville Deb J , Davidson Andrew J , McKenzie Ian M , Mackey David A , McKenzie John , Elder James E 
Published: November 2007

Abstract Purpose: The aim of the present study was to test the hypothesis that adjunctive local anaesthesia decreases postoperative pain, vomiting or length of stay in children having strabismus repair Method: A prospective, randomized, triple‐armed clinical trial involving a treatment comparison between topical amethocaine, sub‐conjunctival bupivacaine and, as a placebo, topical normal saline was performed. All treatments were given at the end of surgery before emergence from the anaesthetic. Results: Overall, there was no statistically significant difference between outcome measures in the three trial groups. Using post hoc analysis there was a statistically significant difference between the groups receiving amethocaine and bupivacaine compared with the saline group in terms of the pain score at 120 min postoperatively. This difference has little clinical significance. Conclusions: Neither topical amethocaine nor subconjunctival bupivacaine makes a clinically significant difference to postoperative pain, emesis or length of stay. Moderate dose paracetamol per rectum alone appears to be effective analgesia for strabismus surgery, although it probably masked any small adjunctive effect of the topical anaesthesia used in the present trial.
Motion capture and the ‘Ouchi’ effect
Authors: Hine Trevor J , Cook Michael , Zanker Johannes M 
Published: November 2007

Abstract Purpose: The role of motion contrast and motion capture in the ‘Ouchi’ effect was investigated in a simplified stimulus. Methods: Sinewave gratings were rapidly oscillated vertically within two concentric stationary ‘apertures’, an innerdisc surrounded by an annulus. Results: A strong illusion of relative motion between the disc and annulus is observed in the horizontal direction for 8 and 12 cycles/deg given small orientation differences between the two gratings. Conclusion: These parameters coincide with those of the ‘Ouchi’ effect, suggesting a sharing of the same causal mechanism.
Motion perception in global versus local attentional modes
Authors: Duke CC , Crewther SG , Lawson ML , Henry L , Kiely PM , West SJ , Crewther DP 
Published: November 2007

Abstract Purpose: Global and local attention are two forms of selective visual attention which activate different areas of the cortex. The purpose of this experiment was to test subjects' motion coherence thresholds under conditions of global or local attention. It was hypothesized that thresholds in global attention would be lower than in local attention. Methods: Eleven adult subjects participated in this study. Subjects were required to identify direction of motion at variable coherence levels, while simultaneously identifying either the global or local letter. Three velocities were used for coherent motion (3, 6 and 18°/s). Results: The results showed that letter identification (global or local) did not significantly affect motion coherence thresholds; however; thresholds were significantly higher at 18°/s than in the lower velocities. Conclusions: These results highlight the attentional limitations of visual information shown by increased motion coherence thresholds when two objects must be identified simultaneously in a brief display.
Intracellular structures of retinal vascular endothelium in normal and early diabetic rats
Authors: Yu PK , Yu DY , Alder VA , Su EN , Cringle SJ 
Published: November 2007

Abstract Purpose: To determine whether the arrangement of microfilaments in retinal vascular endothelium is altered in early diabetes. Methods: F‐actin and nuclei of retinal vascular endothelial cells of normal and diabetic (28 weeks postinduction) rats were examined using confocal microscopy. Results: An increase in the incidence of aberrant F‐actin bundle arrangement in the diabetic retinal arteriole was observed, but there was no disruption of peripheral border F‐actin. The diameter of superficial capillaries was increased in diabetic rats. Conclusion: These changes may be related to the endothelial dysfunction demonstrated in a previous pharmacological study.
Preservation of vasoactive properties of human retinal arteries after cryopreservation
Authors: Su Er‐Ning , Yu Dao‐Yi , Cringle Stephen , Alder Valerie , Yu Paula , Buckland Lisa 
Published: November 2007

Abstract Purpose: Although we have several established in vitro systems for studying the vasoactive properties of the ocular vasculature. the restricted availability of human donor tissue has forced us to rely predominantly on animal studies. Methods: The present paper describes, for the first time, a controlled‐rate cryopreservation technique capable of maintaining vasoactive function in human retinal arteries after extended storage. Results/Conclusion: The response to constrictive (erdothelin‐1) and vasodilatory agents (nimodipine and betaxolol) was comparable with that in fresh pig vessels. It is now possible to obtain multiple segments of retinal artery from a single donor eye and to preserve them for detailed pharmacological assessment.
Patterns of peri‐operative prophylaxis for cataract surgery: A survey of Australian ophthalmologists
Authors: Morlet Nigel , Gatus Barrie , Coroneo Minas 
Published: November 2007

Abstract Background: Although peri‐operative prophylaxis to prevent endophthalmitis is commonly practised by ophthalmologists, no one method has clearly been demonstrated to be more effective than another. We surveyed 570 Fellows of the Royal Australian College of Ophthalmologists to determine what their methods of prophylaxis were and whether these differed for patients who developed endophthalmitis. Methods: The questionnaire asked about the types of antibiotics and other methods of prophylaxis used before, during and after cataract surgery. Of those who reported cases of endophthalmitis, we asked specifically about the methods of prophylaxis used for those patients. Results: The response was 89% and the incidence of endophthalmitis was calculated as 0.11%. There was little difference in the methods of prophylaxis used by those who reported endophthalmitis compared with others, but pre‐operative antibiotics were used more commonly by those who reported the disease (P= 0.06). Surgeons who had practised for 20 years or more reported a lower rate of endophthalmitis than others, as did those who performed more than 300 cataract operations per year. However, the pattern of prophylaxis used by these two sub‐groups was quite divergent. Differences in the methods of prophylaxis had no bearing on the development of endophthalmitis, with the exception that subconjunctival antibiotics were used less often in those patients who developed the disease (P= 0.03). Conclusions: The results of the present study provide no clear answer regarding appropriate peri‐operative prophylaxis. The wide range of prophylactic regimens used suggests that no one method is superior to another. Formal case‐controlled studies are required to identify which method would be most efficacious.
Immunocytochemical localization of basic fibroblast growth factor and glial fibrillary acidic protein after laser photocoagulation in the Royal College of Surgeons rat
Authors: Chu Yi , Humphrey Martin F , Alder Valerie V , FRACS Ian J Constable 
Published: November 2007

Abstract Purpose: Argon laser photocoagulation slows photoreceptor degeneration in the Royal College of Surgeons (RCS) rat, as does intravitreal injection of basic fibroblast growth factor (bFGF). We hypothesize that up‐regulation of retinal bFGF is a consequence of laser lesioning in RCS rats. Therefore, we examined the localization of bFGF after laser and correlated this with Müller cell glial fibrillary acidic protein (GFAP) expression, which is known to increase after injury. Methods: A total of 34 RCS rats at postnatal day 23 were anaesthetized (ketamine 40 mg/kg) and their retinas were irradiated with a grid pattern of 40 non‐overlapping argon green lesions with a power of 120 mW for 0.2 s using a 50 μm spot size. At 0,6, 12,24 and 48 h and 7, 14 and 21 days post‐lesion, rats were anaesthetized and their eyes were enucleated and cryostat sectioned and the sections were processed using either an antibody to bFGF or GFAP using the standard avidin‐biotinylated peroxidase complex method. Five age‐matched RCS rats without laser lesions served as controls. Results: Basic fibroblast growth factor immunoreactivity (IR) was normally located within cells in the ganglion cell layer, inner nuclear layer and in retinal pigment epithelium cells and in the extracellular matrix/cell membranes of the outer nuclear layer (ONL). In lasered retinas, there was elevated bFGF‐IR in the coagulated outer segments for the first 24 h. Retinal blood vessels/Müller cells/astrocytes were moderately labelled in and near each lesion immediately after lesion and became more intense after 48 h and persisted for at least 21 days. There was an elevation of bFGF‐IR in the ONL on the lesion flanks at 14 days. Müller cell GFAP‐IR was first detected at 6 h post‐lesion and spread for a considerable distance beyond the lesion site. At 7 and 14 days, Müller cells at the lesion site had sprouted, while those on the flanks were still GFAP‐IR. Conclusions: Following laser lesion there was an increase in bFGF at the lesion core only for the first 24 h. However elevated levels of bFGF were observed in the ONL at 14 days, which extended into the lesion flanks for a similar distance to that over which increased photoreceptor survival is found. These results provide support for the hypothesis that laser lesions induce bFGF and this may be the mechanism whereby photoreceptors are spared. Müller cell activation is consistent with growth factor stimulation, but was more widespread than the bFGF changes in ONL. However blood vessel labelling was similarly widespread and so the responses may be linked between Müller cell GFAP reaction and blood vessel bFGF localization after laser lesions.
Current concepts in monitoring patients on antimalarials
Authors: Easterbrook Michael 
Published: November 2007

Summary1. Patients should be assessed within 6 months after starting antimalarials.2. Appropriate examination should include visual acuity, colour vision testing (Ishihara), Amsler and corneal examination.3. Routine automated perimetry is not indicated.4. Patients with no risk factors need to be examined no more than once a year.
Diode laser cyclophotocoagulation: Dose‐standardized therapy in end‐stage glaucoma*
Authors: Walland Mark J. 
Published: November 2007

Abstract Background: Ciliary body ablation in end‐stage glaucoma has been widely performed with cryotherapy and neodymium: yttrium aluminium garnet (Nd: YAG) laser; both techniques frequently involving considerable pain and postoperative inflammation, with an unpredictable final intraocular pressure (IOP) and a significant risk of phthisis. Diode laser cyclophotocoagulation (cyclodiode laser) has recently been introduced in an attempt to avoid some of these problems. Methods: Thirty patients with uncontrolled IOP and advanced glaucoma were divided on clinical grounds into two groups and were treated with either a half or a full standardized dose of laser (40 × 1500 mW for 1500 ms) and monitored for IOP control, visual acuity, postoperative inflammation and phthisis. Success of IOP control was defined as IOP < 22 mmHg or a decrease in IOP of > 30%; preservation of visual acuity or control of pain in blind eyes was also assessed. Results: A sustained lowering of IOP was achieved in 90% of patients, with a mean follow up of 10.4 months. For the full treatment cases (group A), mean (± SD) pre‐operative and postoperative IOP was 49.4 ± 11.2 and 25.8 ± 17.7 mmHg, respectively (a 48% reduction); 55% of patients achieved IOP < 22 mmHg and 68% gained an IOP reduction of > 30%. For the half‐treatment cases (group B), the mean preoperative and postoperative IOP was 29.4 ± 4.3 and 18.9 ± 5.7 mmHg, respectively (a 36% reduction); 63% of patients achieved IOP < 22 mmHg and 50% gained an IOP reduction of > 30%. Neovascular glaucoma was present in 60% of patients; the full‐treatment subgroup of these patients achieved a mean lowering of IOP of 58%. Of 22 sighted eyes, 11 (50%) recorded no change in vision; seven (32%) eyes lost and four (18%) eyes gained vision; pain control was achieved in six of eight blind eyes (75%). There was no significant postoperative inflammation, one case of hypotony and no suggestion to date of sympathetic ophthalmia. Conclusion: Diode laser cyclophotocoagulation appears to be simple, safe and is frequently successful in the control of IOP in end‐stage glaucoma. Optimum dosage parameters remain to be determined.