Why is the General Ophthalmic Services (GOS) Contract that underpins primary eye care in the U.K. contrary to the public health interest?

The model for delivery of primary eye care in Europe varies from country to country with differing reliance on ophthalmologists, optometrists and dispensing opticians. Comparative analysis of models has tended to focus on interprofessional working arrangements, training and regulatory issues, rather than on whether a particular model is effective for delivering public health goals for that country. National Health Service (NHS) primary eye care services in the UK are predominantly provided under a General Ophthalmic Services (GOS) Contract between the NHS and practice owners (Contractors). Over two-thirds of sight tests conducted in England, Wales and Northern Ireland and all in Scotland are performed under a GOS Contract, however many people entitled to a GOS sight test do not take up their entitlement. The fee paid for sight tests conducted under a GOS Contract in England, Wales and Northern Ireland does not cover the full cost of conducting the examination. The shortfall must be made up through profits of sale of optical appliances but this business model can be a deterrent to establishing practices within socioeconomically deprived communities, and can also be a barrier to uptake of sight tests, even though many people are entitled to a NHS optical voucher towards the cost of spectacles or contact lenses. This paper critiques the GOS Contracts within the UK. We argue that aspects of the way the GOS Contract is implemented are contrary to the public health interest and that different approaches are needed to address eye health inequalities and to reduce preventable sight loss.

RCT on gentian violet versus a hydrogel dressing for radiotherapy-induced moist skin desquamation.

OBJECTIVE: Radiotherapy-induced moist desquamation is a significant problem but there is a paucity of randomised data on which to base treatment decisions. The current prospective randomised trial compared gentian violet (GV) to a hydrogel dressing in this context. METHOD: Thirty patients undergoing radiotherapy to the head and neck region or breast who had developed moist desquamation in the radiotherapy field were randomised to treatment with 0.5% aqueous gentian violet (GV) (n=16) or a hydrogel dressing (n=14). The area of desquamation was regularly measured until healing or withdrawal from the study. RESULTS: The likelihood of healing with the hydrogel was greater than GV with a hazard ratio for healing of 7.95 (95% CI 2.20-28.68; p=0.002). The median time to healing for hydrogel was 12 days but had not been reached for GV by 30 days. Over the first 14 days the median'area under curve' of moist desquamation for GV was 82.6 cm2 (range 31.8-320.7 cm2) and that for hydrogel 20.0 cm2 (range 3.8-301.0 cm2) (difference significant at p=0.003). Ten of 16 patients treated with GV withdrew from the study (due to stinging in five and failure to heal in five) compared with two of the 14 treated with hydrogel (difference significant at p=0.021). CONCLUSION: Hydrogel dressings are more likely to heal radiotherapy-induced moist desquamation and are better tolerated than GV.

Neonatal 6-hydroxydopamine lesions of the frontal cortex in rats: persisting effects on locomotor activity, learning and nicotine self-administration.

Dopaminergic innervation of the frontal cortex in adults is important for a variety of cognitive functions and behavioral control. However, the role of frontal cortical dopaminergic innervation for neurobehavioral development has received little attention. In the current study, rats were given dopaminergic lesions in the frontal cortex with local micro-infusions of 6-hydroxydopamine (6-OHDA) at 1 week of age. The long-term behavioral effects of neonatal frontal cortical 6-OHDA lesions were assessed in a series of tests of locomotor activity, spatial learning and memory, and i.v. nicotine self-administration. In addition, neurochemical indices were assessed with tissue homogenization and HPLC in the frontal cortex, striatum, and nucleus accumbens of neonatal and adult rats after neonatal 6-OHDA lesions. In neonatal rats, frontal 6-OHDA lesions as intended caused a significant reduction in frontal cortical dopamine without effects on frontal cortical 5-HT and norepinephrine. The frontal cortical dopamine depletion increased 5-HT and norepinephrine levels in the nucleus accumbens. Locomotor activity assessment during adulthood in the figure-8 maze showed that lesioned male rats were hyperactive relative to sham-lesioned males. Locomotor activity of female rats was not significantly affected by the neonatal frontal 6-OHDA lesion. Learning and memory in the radial-arm maze was also affected by neonatal frontal 6-OHDA lesions. There was a general trend toward impaired performance in early maze acquisition and a paradoxical improvement at the end of cognitive testing. Nicotine self-administration showed significant lesion x sex interactions. The sex difference in nicotine self-administration with females self-administering significantly more nicotine than males was reversed by neonatal 6-OHDA frontal cortical lesions. Neurochemical studies in adult rats showed that frontal cortical dopamine and DOPAC levels significantly correlated with nicotine self-administration in the 6-OHDA-lesioned animals but not in the controls. Frontal cortical 5-HT and 5HIAA showed inverse correlations with nicotine self-administration in the 6-OHDA-lesioned animals but not in the controls. These results show that interfering with normal dopamine innervation of the frontal cortex during early postnatal development has persisting behavioral effects, which are sex-specific.

Clinical evaluation of the model AT-45 silicone accommodating intraocular lens: results of feasibility and the initial phase of a Food and Drug Administration clinical trial.

OBJECTIVE: To evaluate the clinical outcomes in cataract patients after implantation of an accommodating intraocular lens, designed to move forward and backward along the visual axis. DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Sixty-two patients scheduled for small-incision, extracapsular cataract extraction by phacoemulsification. METHODS: Twenty-eight eyes of 14 patients in the feasibility phase of the study and 48 eyes of 48 patients in the next phase of study underwent cataract extraction and implantation of the AT-45 accommodating intraocular lens. Prospective follow-up was analyzed at 1 month after surgery and compared with baseline characteristics 1 month and 3 to 6 months after surgery. MAIN OUTCOME MEASURES: Postoperative distance (uncorrected and best corrected), near (uncorrected, through the distance correction, best-corrected, i.e., with add), and intermediate (through the distance correction) visual acuity. RESULTS: All patients with monocular pseudophakia had best-corrected distance visual acuity of 20/40 or better. Patients with bilateral pseudophakia had best-corrected visual acuity of 20/25 or better when tested binocularly. The results from 28 eyes of 14 patients participating in the feasibility study were combined with those from 48 eyes of 48 patients included in the next phase of the AT-45 study. Uncorrected distance visual acuity was 20/40 or better in most patients (90%, or 56 of 62 eyes implanted and available for follow-up). Ninety-seven percent of patients (60/62) had uncorrected near visual acuity of 20/30 or better. Forty-eight eyes had intermediate visual acuity measured at 28 inches without 'add', and 44 of them (92%) achieved 20/30 or better. No complications or adverse events were reported. CONCLUSIONS: The AT-45 accommodating intraocular lens, designed to allow movement along the visual axis of the eye by using the natural physiology of the intact ciliary muscle after cataract removal, provides patients with excellent uncorrected distance, intermediate, and near visual acuity and should be considered as a modality to allow the majority of pseudophakic patients to see at all distances without glasses.

Biological evaluation of ring- and side-chain-substituted m-iodobenzylguanidine analogues.

A number of ring- and side-chain-substituted m-iodobenzylguanidine analogues were evaluated for their lipophilicity, in vitro stability, uptake by SK-N-SH human neuroblastoma cells in vitro, and biodistribution in normal mice. As expected, the lipophilicity of m-iodobenzylguanidine increased when a halogen was introduced onto the ring and decreased with the addition of polar hydroxyl, amino, and nitro substitutents. Most of the derivatives showed reasonable stability up to 24 h in PBS at 37 degrees C. While N(1)-hydroxy-N(3)-3-[(131)I]iodobenzylguanidine and 3,4-dihydroxy-5-[(131)I]iodobenzylguanidine generated a more nonpolar product in addition to the free iodide, 3-[(131)I]iodo-4-nitrobenzylguanidine decomposed to a product more polar than the parent compound. The specific uptake of 4-chloro-3-[(131)I]iodobenzylguanidine, 3-[(131)I]iodo-4-nitrobenzylguanidine, and N(1)-hydroxy-N(3)-3-[(131)I]iodobenzylguanidine by SK-N-SH human neuroblastoma cells in vitro, relative to that of m-[(125)I]iodobenzylguanidine, was 117 +/- 10%, 50 +/- 4%, and 12 +/- 2%, respectively. The specific uptake of the known m-iodobenzylguanidine analogues 4-hydroxy-3-[(131)I]iodobenzylguanidine and 4-amino-3-[(131)I]iodobenzylguanidine was 80 +/- 4% and 66 +/- 4%, respectively. None of the other m-iodobenzylguanidine derivatives showed any significant specific uptake by SK-N-SH cells. Heart uptake of 4-chloro-3-[(131)I]iodobenzylguanidine in normal mice was higher than that of m-[(125)I]iodobenzylguanidine at later time points (11 +/- 1% ID/g versus 3 +/- 1% ID/g at 24 h; p < 0.05) while uptake of 3-[(131)I]iodo-4-nitrobenzylguanidine and of N(1)-hydroxy-N(3)-3-[(131)I]iodobenzylguanidine in the heart was lower than that of m-iodobenzylguanidine at all time points. In accordance with the in vitro results, none of the other novel m-iodobenzylguanidine derivatives showed any significant myocardial or adrenal uptake in vivo.

Anatomic factors affecting microkeratome placement in laser in situ keratomileusis(2)(2).

PURPOSE: To identify the significant anatomic factors that affect placement of 2 microkeratomes and compare the ease of their placement. SETTING: The Laser Center, Houston, Texas, USA. METHODS: Anatomic factors affecting microkeratome placement were evaluated in 250 eyes of 137 myopic patients in a prospective consecutive-enrollment study. Anatomic factors measured included vertical orbital width, horizontal interpalpebral fissure (HPF), corneal diameter, and position of the corneal apex relative to the lateral orbital rim (PCL). Vertical orbital width and HPF were measured with a micrometer caliper (Mitutoyo); corneal diameter, with Orbscan topography (Bausch & Lomb Surgical); and PCL, with a Hertel exophthalmometer. Patients were randomly divided into 2 groups (125 eyes/group) to have surgery with the Automated Corneal Shaper((R)) (ACS) (Bausch & Lomb Surgical) or Hansatome (Bausch & Lomb Surgical) microkeratome. Microkeratome placement was graded by 1 surgeon as "easy" (grades 1, 2, and 3) or "difficult" (grades 4 and 5). Results were correlated with anatomic factors to evaluate possible anatomic influences on the difficulty of microkeratome placement. RESULTS: The PCL and vertical orbital width were statistically significant factors in predicting the difficulty of ACS microkeratome placement (P <.05). For the Hansatome microkeratome, since only 1 eye was graded as a difficult placement, the anatomic parameters affecting placement could not be evaluated. There were no statistically significant between-group differences in mean age and means of all anatomic factors measured (independent t test, P >.05). Difficult applanations were encountered in the ACS group (8/125 eyes, 6.4%) more than in the Hansatome group (1/125 eyes, 0.8%), which was a statistically significant difference by the Pearson chi-square test (P <.05). CONCLUSIONS: The PCL and vertical orbital width were significant anatomic factors affecting placement of the ACS microkeratome. The anatomic factors affecting Hansatome microkeratome placement could not be determined. The percentage of difficult placements was significantly lower with the Hansatome than with the ACS.

Diffuse lamellar keratitis related to endotoxins released from sterilizer reservoir biofilms.

OBJECTIVE: To investigate the risk factors and control mechanisms used to control the outbreak of diffuse lamellar keratitis (DLK) associated with laser in situ keratomileusis (LASIK) and examine the relationship between DLK and endotoxins released from sterilizer biofilm reservoirs. DESIGN: Clinic-based cohort and laboratory study. PARTICIPANTS: All patients undergoing LASIK at our clinic from October 7, 1998 through August 31, 1999. The case definition was a diffuse infiltrate in the interface developing within the first week after surgery. INTERVENTIONS: Biofilm control in the sterilizer, changes in sterilizer, distilled water, instruments, and irrigating fluids. MAIN OUTCOME MEASURES: The incidence of DLK after LASIK surgery. RESULTS: There were 983 evaluable patients, with three whose DLK status was not recorded. There were 52 cases of DLK. Burkholderia pickettii was isolated from the sterilizer reservoir. Potential risk factors and associations, for which there was no significant difference, included age and sex of the patients, surgeon, operating suite temperature or humidity, drapes used, saline solutions used, time of day the surgery was performed, and microkeratome use. Sterilizers 1 and 2, before biofilm control, were compared with sterilizer 3, after control. The relative risk was 9.4 (confidence limits [CL], 7.5-11.8) for sterilizer 1 versus 3 and 18. 7 (CL, 11-32) for sterilizer 2 versus 3. Three cases occurred after biofilm control, but were sporadic in nature and associated with epithelial defects. CONCLUSIONS: Clusters of DLK may be related to endotoxins released from gram-negative biofilms in sterilizer reservoirs. We experienced an outbreak of DLK affecting 52 patients and isolated B. pickettii from the sterilizer reservoir. Epidemiologic investigation showed that biofilm control in the sterilizer reservoirs was associated with a significant reduction in the development of DLK. We encourage any clinics that experience a cluster of DLK to consider microbiologic and epidemiologic investigation for the effectiveness of sterilizer biofilm control.

Teaching family practice residents breast cyst aspiration.

OBJECTIVE: To conduct the first study of teaching family practice residents the technique of breast cyst aspiration (BCA) using the Toronto Breast Cyst Aspiration Model (TBCAM) in a workshop. To determine whether this training increases their likelihood of performing the procedure in the future. To discover how residents evaluate the workshop as a teaching method. DESIGN: Prospective parallel-group trial from August to November 1997. Baseline questionnaires were given to both experimental and control groups in August. The experimental group was given a 1.5-hour workshop and a postworkshop questionnaire. Both groups were then given 3-month follow-up questionnaires. SETTING: Family practice residency program at the University of Toronto. PARTICIPANTS: The experimental group consisted of 15 family practice residents from one university-affiliated hospital site. The control group consisted of 54 family practice residents selected from the remaining sites. MAIN OUTCOME MEASURES: Confidence score, likelihood of performing BCA, and effectiveness of the workshop rated on a Likert scale ranging from 1-low to 5-high; and knowledge of BCA rated from 0 to 7. RESULTS: Three months after the workshop, 62% of study subjects and 31% of controls were above the median confidence score of 3.2 (chi 2 3.4, P > .05); 76% of subjects but only 11% of controls were above the median knowledge score of 4 (chi 2 16.67, P < .001); and 75% of subjects and 34% of controls were above the median likelihood to perform score of 3 (chi 2 5.37, P < .05). Most (95%) workshop effectiveness scores were 4s or 5s. CONCLUSIONS: Workshop training resulted in higher confidence, greater knowledge, and more likelihood of performing BCA. The workshop using the TBCAM was evaluated as a highly effective way to teach BCA.

Accuracy of patient positioning during radiotherapy for bladder and brain tumours.

We report the results of a prospective study to quantify inaccuracies in patient set-up during routine radiotherapy for tumours of the brain and bladder, which took place as part of our departmental development. Knowledge of these inaccuracies is required to put into practice the ICRU 50 recommendations regarding clinical target volume and planning target volume. We measured inaccuracies in two dimensions by comparing portal beam films with the simulator check film. Our method used manual measurements, proved to be a very laborious technique, and demonstrated the need for portal imaging. Ninety-five brain and 97 bladder portal films from 30 brain and 30 bladder patients were examined. Displacements greater than 0.5 cm were seen in 13% of brain treatments in the supero-inferior direction and 1% in the anteroposterior direction. With bladder treatments, displacements greater than 0.75 cm were seen in 12% in the supero-inferior direction and 5% in the lateral direction. These results are consistent with other previous studies. We identified a very small systematic error in the department, which was not [corrected] considered to be clinically significant. These results are discussed with reference to other similar studies and the ICRU 50 recommendations.

Radioiodinated antibody targeting of the HER-2/neu oncoprotein: effects of labeling method on cellular processing and tissue distribution.

Monoclonal antibody (MAb) internalization can have a major effect on tumor retention of radiolabel. Two anti-HER-2/neu MAbs (TA1 and 520C9) were radioiodinated using the iodogen, N-succinimidyl 5-iodo-3-pyridinecarboxylate (SIPC), and tyramine-cellobiose (TCB) methods. Paired-label studies compared internalization and cellular processing of the labeled MAbs by SKOv3 9002-18 ovarian cancer cells in vitro. Intracellular radioiodine activity for 520C9 was up to 2.6 and 3.0 times higher for SIPC and TCB labeling, respectively, compared with iodogen. Likewise, intracellular activity for TA1 was up to 2.3 and 2.9 times higher with the SIPC and TCB methods compared with iodogen labeling. Unfortunately, similar advantages in tumor accumulation were not achieved in athymic mice bearing SKOv3 9008-18 ovarian cancer xenografts.

Draping technique to isolate lashes and achieve maximum exposure.

A surgical draping technique is presented that decreases surgical time, maximizes surgical site exposure, and decreases the risk of infection. It was also designed to enhance patent comfort.

Blocking [211At]astatide accumulation in normal tissues: preliminary evaluation of seven potential compounds.

Normal tissue accumulation of 211At must be minimized during targeted radiotherapy with 211At-labeled compounds. Therefore, we investigated the ability of seven compounds to block normal organ uptake of [211At]astatide in mice: potassium iodide, sodium thiocyanate, sodium perchlorate, sodium periodate, cysteine, 2,3-dimercapto-1-propanesulfonic acid, and meso-2,3-dimercaptosuccinic acid. The monovalent anions I-, SCN-, and ClO4- reduced 211At uptake in stomach and thyroid, while thiocyanate and cysteine were the only compounds to significantly reduce activity levels in lungs and spleen. This study suggests that blocking agents may help reduce normal organ radiation doses in endoradiotherapeutic procedures with 211At-labeled radiopharmaceuticals.

Corneal endothelial changes after divide and conquer versus chip and flip phacoemulsification.

PURPOSE: To evaluate changes in central corneal endothelial cells and corneal thickness after divide and conquer phacoemulsification and chip and flip phacoemulsification. SETTING: Houston Eye Clinic, Houston, Texas, USA. METHODS: Forty-four eyes were randomly assigned to one of two groups to have divide and conquer (D/C Group) or chip and flip (C/F Group) phacoemulsification with implantation of a posterior chamber, foldable, silicone intraocular lens performed by one surgeon. Of these, 41 eyes of 37 patients (22 D/C Group, 19 C/F Group) met the inclusion criteria. All surgeries were uneventful. A complete eye examination including specular microscopy and pachymetry was performed preoperatively and 1 week and 1 and 3 months postoperatively. RESULTS: There were no significant between-group differences in any of the following means: sex; age; time at 70% phaco power; total phacoemulsification time. No correlation was found between ultrasound time and increased corneal thickness except for a significant increase in percentage of hexagonal cells in the C/F Group at 1 month. The only statistically significant between-group differences were greater endothelial cell loss in the C/F Group at 1 month and the percentage change in hexagonal cells at 1 week (1.1% increase, D/C Group; 10.7% decrease, C/F Group). CONCLUSION: The divide and conquer technique led to less endothelial loss and hexagonal cell change than the chip and flip technique, although at 3 months the differences were not significant.

Ocular integrity after refractive procedures.

PURPOSE: The purpose of the study was to determine the integrity of human eyes after refractive procedures. METHODS: Whole human globes underwent either radial keratotomy (RK) with eight incisions, automated lamellar keratoplasty (ALK), photorefractive keratectomy (PRK), or excimer laser assisted in situ keratomileusis (LASIK). Eyes then were subjected to quantitatively increasing levels of trauma until rupture occurred. RESULTS: All eyes operated on required less energy to rupture as compared with that of control eyes. The mean number of trials required for rupture is as follows (energy doubled with each successive trial): normal, 4.29; LASIK, 3.80; ALK, 3.67; PRK, 3.60; and RK, 2.83. The level of energy required to rupture normal, ALK, PRK, and LASIK eyes was not significantly different. All RK eyes ruptured at incisions. Most ALK, PRK, and LASIK eyes ruptured near the flap edge or limbus. Most normal eyes ruptured with both corneal and scleral involvement. Age of tissue donors at the time of death and time elapsed between death and procedure were not significantly different between groups (P = 0.88 and 0.79, respectively). CONCLUSIONS: The energy required to rupture ALK, PRK, and LASIK eyes is not significantly different from that for normal eyes. The RK eyes ruptured with significantly less energy than did normal eyes. All RK eyes ruptured at incision sites.

Radioiodinated antibody targeting of the HER-2/neu oncoprotein.

The HER-2/neu oncogene encodes a 185 kDa phosphoglycoprotein that is overexpressed in breast, ovarian and other cancers. Seven monoclonal antibodies reactive with oncoprotein were labeled with 131I. In vitro experiments with SKOv3 9002-18 cells determined binding affinity, internalization and degradation. The biodistribution of these antibodies in comparison to 125I-labeled nonspecific antibody was measured in athymic mice with SKOv3 9002-18 ovarian carcinoma xenografts. Antibody 520C9 exhibited the highest and most specific retention in tumor, peaking at 17.4 +/- 5.6% ID/g at 24 h.

A comprehensive approach to LASIK.

Candidates for LASIK procedures should have a stable refraction for at least 12 months. The three main contraindications for LASIK include patients with keratoconus or autoimmune disease and active corneal or ocular disease. The proper laser room environment is critical for optimal laser performance. The temperature should be maintained between 18 degrees C and 24 degrees C, and the humidity should be kept below 50%.

Six-month results of the multicenter phase I study of excimer laser myopic keratomileusis.

We report six-month results of the Summit Technology Myopic Keratomileusis Phase I multicenter study. Fifty-seven eyes of 57 patients had keratomileusis to correct high myopia. A microkeratome was used for the primary keratectomy and the excimer laser was used to ablate the stroma of the resected lenticle (cap) or the stromal bed (in situ). At six months, 31 of the 47 eyes available for follow-up (65.9%) had uncorrected visual acuity of 20/40 or better; 16 (34.0%) had uncorrected acuity of 20/25 or better. Thirty-seven eyes (78.7%) maintained the same (+/- one Snellen line) best corrected visual acuity as before surgery; seven (14.9%) lost two lines and three (6.4%) lost more than two lines. In addition to the six-month multicenter study results, we report two year results in a subset of 28 eyes (22 from the multicenter study and six fellow eyes). At six months, 17 of the 24 eyes available for follow-up (70.9%) had uncorrected visual acuity of 20/40 or better and nine (37.5%) had uncorrected acuity of 20/25 or better, including eyes that had worse than 20/80 best corrected visual acuity preoperatively. At 24 months, five of the seven eyes available for follow-up (71.4%) had uncorrected acuity of 20/25 or better. Only one patient lost two lines of best corrected vision at six months and no patient lost more than two lines; at 24 months, all patients maintained (+/- one line) best corrected vision.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative pachometry during automated lamellar keratoplasty: a preliminary report.

BACKGROUND: The hinge technique greatly improves the results of automated lamellar keratoplasty but makes it impossible to measure the thickness of the corneal cap with a micrometer. We developed a technique of measuring cap and stromal disc thickness with a pachometer and compared the results with those obtained with a micrometer. METHODS: Measurements of the thickness of the stromal disc and/or corneal cap were taken with the Mitutoyo micrometer and the Chiron Corneo-Gage System III pachometer in five myopic and three hyperopic cases undergoing automated lamellar keratoplasty with complete cap resection. The intended postoperative refraction was plano. Postoperative refractions were taken at two months. RESULTS: In most cases, the corneal cap measured thinner while the stromal disc measured thicker by the micrometer than by the pachometer because of the hydration status of the stromal bed. In both myopic and hyperopic cases, the thickness measurements taken with the pachometer correlated better with the postoperative spherical equivalent values than those taken with the micrometer. CONCLUSIONS: The thickness measurement of corneal resections by both micrometry and pachometry is greatly influenced by tissue hydration status. When hydration is similar, the pachometer provides more accurate thickness readings than does the micrometer, as determined by correlations with intended refractive results.