The Hoya ULT-2000 and ULT-3000 universal light-transmission meters:a comparison using spectrophotometric data and Australian Sunglass Standard 1067–1990.

The Hoya ULT-2000 has been shown previously to be a valid method of assessing uniformly tinted sunglass lenses with reference to Australian Standard 1067–1983. It is now superseded by the Hoya ULT-3000. The performances of the Hoya ULT-2000 and ULT-3000 were compared in two experiments using lenses calibrated spectrophotometrically. The transmittance of 37 pairs of currendy available uniformly tinted sunglasses'of various materials were assessed according to AS1067-1990 and compared to the values indicated by ULT-2000 and ULT-3000. The validities of near-ultraviolet, luminous and near infra-red transmittance estimates were evaluated using glass neutral density filters (neutral in both the visible and infrared regions) and highly coloured calibrated glass cut-off filters.     

The Hoya Ult-2000 Universal Light Transmission Meter: A Comparison with Spectrophotometric Data

The transmittance properties of 25 commercially available sunglass lenses measured with the Hoya ULT-2000 Universal Light Transmission Meter were compared with the equivalent requirements specified in Australian Standard AS1067-Sunglass Lenses and calculated from data obtained with a Cary 14 spectrophotometer. The validity of readings obtained with the ULT-2000 as a measure of the requirements of AS1067 is discussed and some possible sources of error in the routine use of the instrument are noted.     

A new high-speed pneumatic vitrectomy cutter

PURPOSE: To describe a new high-speed pneumatic vitrectomy instrument capable of 2000 cuts/minute. DESIGN: Observational report. METHODS: A high-speed guillotine vitrector, developed to perform vitrectomy, with the ability to adjust from 1 to 2000 cuts/minute, was used in 80 consecutive vitreoretinal cases with a variety of diagnoses in a hospital setting. RESULTS: The performance was almost vibration-free. The instrument performed efficiently up to 1500 cuts/minute during vitrectomy, maintaining a constant flow rate. Higher cutting rates were used successfully for special indications. No complications were linked to the use of the instrument. CONCLUSION: The instrument was used successfully in 80 consecutive vitrectomies for a variety of diagnoses, performing efficiently up to 1500 cuts/minute, with a constant flow rate without complications. Higher cutting rates (2000 cuts/minute) were used successfully for special indications.     

Clinical assessment of two new contrast sensitivity charts

BACKGROUND: Contrast sensitivity measurement in UK clinical practice is most commonly performed with the Pelli-Robson chart. AIMS: To compare the repeatability of two new contrast sensitivity charts and to measure their agreement with the Pelli-Robson charts. METHOD: Contrast sensitivity was measured monocularly using two versions of the Mars letter contrast sensitivity chart, two presentations on the Test Chart 2000 and two versions of the Pelli-Robson chart. Bland-Altman techniques were used to assess repeatability and agreement. RESULTS: 53 subjects were recruited with visual acuity from 6/4 to 6/72. The coefficient of repeatability was 0.182 for the Pelli-Robson chart, 0.121 for the Mars chart and 0.238 for Test Chart 2000. Limits of agreement with the Pelli-Robson chart were -0.29 to +0.15 log units for the Mars letter contrast sensitivity chart and -0.32 to +0.78 log units for the Test Chart 2000. For patients with poor contrast sensitivity, the limits of agreement between the Test Chart 2000 and the Pelli-Robson chart improved from -0.33 to +0.15 log units. CONCLUSION: In a population of hospital ophthalmology patients, the coefficient of repeatability is better for the Mars chart and worse for the Test Chart 2000 when compared with the Pelli-Robson chart. The electronic test chart does not agree well with the Pelli-Robson chart, although this might simply be due to the performance of liquid crystal display screens at low contrast levels. The Mars letter contrast sensitivity chart shows good validity and reasonable agreement with the Pelli-Robson chart.     

Clinical comparison of the Keeler Pulsair 2000, American Optical MkII and Goldmann applanation tonometers

The aim of our study was to evaluate the performance of both the Keeler Pulsair 2000 and the American Optical (AO) MkII non-contact tonometers (NCT) and compare these to the reference Goldmann standard using the same group of patients. Forty-five patients (89 eyes) receiving medical treatment for primary open angle glaucoma had their intraocular pressure (IOP) measured with each instrument in a random order using five experienced observers. In the IOP range of the sample (6–27 mmHg) the difference between means for each tonometer was small. The Pulsair 2000 (mean = 19.06 mmHg, SD 6.28) read slightly higher than Goldmann (mean = 18.01 mmHg, SD 4.88), whereas the AO MkII read slightly lower (mean = 16.27 mmHg, SD 5.93). However, all differences were statistically significant ( P < 0.001, repeat measures ANOVA). Correlation coefficients for Pulsair 2000 versus Goldmann was r = 0.82 and for AO MkII versus Goldmann was r = 0.85. In addition, the repeatability for each NCT was assessed using 10 consecutive measurements on a further 10 subjects. The Pulsair 2000 showed significantly greater variation of IOP (mean SD 3.43 mmHg) than the AO MkII (mean SD 1.76 mmHg), confirming the need for taking at least four readings per eye with the Pulsair 2000. These variations are greater than that generally observed with Goldmann, and possible explanations why this occurs are discussed. In conclusion, subject to these limitations, both NCTs should be useful for measuring IOP as part of a screening protocol for glaucoma.     

Light-induced damage of the retina through slit-lamp photography

Background: I report on two patients who suffered severe loss of visual acuity after slit-lamp photography of the anterior eye segment. Methods: Both patients were pseudophakic and pictures were taken to document the degree of posterior capsule opacification via retroillumination with dilated pupils. Both patients had excellent visual acuity at the time of photography was taken and experienced reduction of to hand movement afterwards. A Zeiss 75 SL device was used for the slit-lamp photography. In cooperation with Carl Zeiss Jena the slit lamp was investigated. Results: Ophthalmoscopy and angiography after photography discovered a central macular defect, similar to a photocoagulation. The visual acuity did not recover. Conclusion: Under certain circumstances slit-lamp photography of the anterior eye segment can lead to severe light-induced damage of the retina. Received: 19 April 2000 Revised: 8 August 2000 Accepted: 17 August 2000     

Diffuse lamellar keratitis complicating laser in situ keratomileusis: post-marketing surveillance of an emerging disease in British Columbia, Canada, 2000-2002

PURPOSE: To describe a surveillance system and summarize data between January 2000 and December 2002 regarding diffuse lamellar keratitis (DLK), a complication of laser in situ keratomileusis (LASIK) surgery. SETTING: Community-based clinics in British Columbia, Canada, in which LASIK surgery is performed. METHODS: Monthly, all clinics in which LASIK is performed reported the number of LASIK procedures and nonnominal cases of DLK (by grade and onset date) to the British Columbia Centre for Disease Control. Diffuse lamellar keratitis outbreaks were investigated, and prevention and control measures were recommended. RESULTS: From 2000 to 2002, approximately 72,000 LASIK procedures were performed, with a mean DLK incidence rate of 0.67% (95% confidence interval, 0.61-0.73). The overall proportion of DLK cases attributed to outbreaks was 64%, decreasing from 72% in 2000 to 40% in 2003. CONCLUSIONS: An effective DLK surveillance program was implemented at all laser refractive clinics in British Columbia. Reported DLK incidence was 0.67 cases per 100 procedures, with 64% occurring in outbreaks.     

Comparisons of Clinical Features in Japanese Patients with Behçet’s Uveitis Treated in the 1990s and the 2000s

ABSTRACT

Purpose: We investigated clinical characteristics of ocular Behçet’s disease (BD) patients treated in the 1990s and the 2000s.

Methods: We retrospectively examined records of 68 newly arrived patients with ocular BD followed for more than 4 months during the 2000s and compared to those of 107 patients during the 1990s. Patient profiles, ocular and systemic symptoms, frequency of ocular attacks, BD ocular attack score 24–6 months (BOS24-6M), best-corrected visual acuity (BCVA), and immunomodulatory treatment were noted.

Results: Clinical characteristics in the 2000s showed increases in iridocyclitis type, intestinal-, vasculo-, and neuro-BD cases, oral corticosteroid, methotrexate, and infliximab therapy usage, cataract and glaucoma surgery, and pseudophakia, and decreases in BOS24-6M and cyclophosphamide usage. BCVA of 20/30 or better at the final visit was slightly increased in the 2000s.

Conclusions: Milder ocular BD tendency was seen in cases in the 2000s, whereas the incidence of special type of BD might be increasing.     

Spatiotemporal properties of stereoacuity

This study investigated the effects of spatial and temporal luminance variations on stereoacuity across three experiments. In Experiment 1, the effect of counterphase flicker on performance was examined at five spatial frequencies. Flicker impaired performance at a high spatial frequency, whereas it improved performance at a low spatial frequency. In Experiment 2, the effect of sustained vs. transient temporal modulation on performance was investigated at four spatial frequencies. Relative to sustained modulation, transient modulation impaired performance at high spatial frequencies, but it affected performance little at low spatial frequencies. In Experiment 3, the effect of exposure duration on performance was examined at three spatial frequencies. Decreasing duration impaired performance at a high spatial frequency, but it affected performance less at low spatial frequencies. These results show that spatial and temporal variables interact to govern stereoacuity performance; stereoacuity is good only when tested with high spatial- and low temporal-frequencies.     

Reproducibility with the Keeler Pulsair 2000 non-contact tonometer.

AIMS--The IOP variation on repeated testing with the recently introduced Keeler Pulsair 2000 instrument was investigated. METHODS--One hundred normal individuals (50 male and 50 female) new to the instrument had three sets of IOP recordings within a 15 minute time period. RESULTS--The mean of the first set of IOPs from both right and left eyes was significantly higher than those from subsequent sets (p < 0.0001 for right eyes and p = 0.01 and < 0.0002 for left eyes). This tendency increased significantly with increasing IOP. Second and third IOP sets were, however, similar indicating stabilisation of IOP measurements. The coefficient of repeatability of the instrument between second and third sets was 4.2 mm Hg for right eyes and 3.6 mm Hg for left eyes. CONCLUSION--The Pulsair 2000 passes the British standard for reproducibility of a standard test method.     

视神经肿瘤36例临床分析

分析视神经源性肿瘤患者的病史、临床表现、影像学检查和治疗方法,为其诊断和治疗提供帮助。 方法：对视神经胶质瘤和视神经鞘脑膜瘤患者的临床资料进行分析。 结果：视神经胶质瘤的15例患者中以发现眼球突出为主诉的病例为6例,以发现视力下降为主诉的5例,眼球突出合并视力下降的2例;视神经鞘脑膜瘤组21例患者中以眼球突出为主诉的病例为13例,视力下降5例,眼球突出合并视力下降的3例。超声检查、CT、MRI检查均有典型表现;30例患者经手术治疗,6例经伽玛刀治疗。 结论:视神经源性肿瘤在眼部检查及影像学表现上有一定的特征性,对于辅助诊断具有重要价值;治疗方案应视患者的具体情况综合制定,目前以手术及放射治疗为主。     

Comparison of manual Goldmann and automated static visual fields using the Dicon 2000 perimeter in the detection of chiasmal tumors

We report that changes in the program (software) operating an automated perimeter (hardware) remarkably improved its ability to produce interpretable diagnostic information. A group of 11 postoperative patients with pituitary adenomas and other chiasmal tumors having stable visual field defects demonstrated by manual kinetic and suprathreshold Goldmann perimetry were re-examined with automated suprathreshold static perimetry performed by the Dicon model 2000 perimeter. During the study a program for two-zone (central and peripheral), three-level suprathreshold static perimetry became available. With optimum test administration and interpretation, the Dicon 2000 perimeter with the two-zone, three-level suprathreshold program can at least equal the performance of an experienced perimetrist using manual Goldmann kinetic and selective static perimetry in the detection of visual field defects resulting from chiasmal tumors. The two-zone, three-level suprathreshold suprathreshold program was superior to a single zone, one-level programs in examining this population.     

Perceived and actual performance of daily tasks: relationship to visual function tests in individuals with retinitis pigmentosa

PURPOSE: To investigate the functioning in daily task performance of individuals with retinitis pigmentosa (RP). Goals were (1) to quantify the relationships among clinical tests of vision, self-reports, and evaluations of actual task performance to predict difficulty in these tasks; and (2) to validate self-report questionnaire data about daily task performance with observations and measurements of actual task performance conducted by a certified low-vision specialist. DESIGN: A cross-sectional study and survey. PARTICIPANTS: Sixty-two individuals with RP (mean age, 37 years) participated in the study. METHODS: We obtained data about task performance from subjects' reports about their daily performance as assessed by a 53-item questionnaire and from a specialist's rating about actual ability on a 64-item battery of tasks, including ones similar to those assessed with the questionnaire. MAIN OUTCOME MEASURES: Clinical measures of vision included visual acuity, visual fields using Goldmann perimetry, letter contrast sensitivity, and cone and rod electroretinogram (ERG) function. The questionnaire and functional tasks were clustered into three categories: "reading," "mobility," and "peripheral detection." RESULTS: Self-report was correlated significantly with actual task performance. Task performance was correlated significantly with clinical test performance. Moderate or worse difficulty in performance was observed only for visual acuity worse than 20/40; log contrast sensitivity less than 1.4; a visual field area smaller than 2000 deg(2) (area equivalent to a 50-degree diameter of visual field to the Goldmann II-4-e target); and ERG amplitudes less than 10 microvolts for 32-Hz light-adapted white flicker. CONCLUSIONS: Despite the significant correlations, there remains variability in task performance that is unaccounted for in some individuals with low levels of clinical test performance. The assessment of actual task performance validated the use of self-reports in individuals with RP.     

Increased growth factor activity in the aqueous humour of patients with exfoliation syndrome

Background: To investigate the growth factor activity in the aqueous humour of patients with exfoliation syndrome (XFS). Methods: We collected 154 aqueous humour samples (69 from patients with XFS and 85 from age-matched controls) prior to routine extracapsular cataract surgery. Growth factor activity was investigated using a [3H]thymidine incorporation assay on McCoy cells that assesses DNA synthesis. Albumin concentration was measured by a radio-immunoassay as an index of blood aqueous barrier integrity. N-Acetylglucosaminidase (NAG) activity, a marker of cellular breakdown, was ascertained by a fluorometric method. Results: XFS aqueous samples exhibited significantly higher growth factor activity than to the control samples (P<0.001). Albumin concentration was also higher in the XFS group. NAG activity was similar in the two groups. No relationship between growth factor activity and the other parameters investigated was found. Conclusions: Increased growth factor activity was detected in the aqueous humour of patients with XFS. This finding may be re-lated to the pathogenesis of XFS. Received: 7 December 1999 Revised: 7 February 2000 Accepted: 9 February 2000     

Validity of endothelial cell analysis methods and recommendations for calibration in Topcon SP-2000P specular microscopy

PURPOSE: To report on the calibration of the Topcon SP-2000P specular microscope and the Endothelial Cell Analysis Module of the IMAGEnet 2000 software, and to establish the validity of the different endothelial cell density (ECD) assessment methods available in these instruments. METHODS: Using an external microgrid, we calibrated the magnification of the SP-2000P and the IMAGEnet software. In both eyes of 36 volunteers, we validated 4 ECD assessment methods by comparing these methods to the gold standard manual ECD, manual counting of cells on a video print. These methods were: the estimated ECD, estimation of ECD with a reference grid on the camera screen; the SP-2000P ECD, pointing out whole contiguous cells on the camera screen; the uncorrected IMAGEnet ECD, using automatically drawn cell borders, and the corrected IMAGEnet ECD, with manual correction of incorrectly drawn cell borders in the automated analysis. Validity of each method was evaluated by calculating both the mean difference with the manual ECD and the limits of agreement as described by Bland and Altman. RESULTS: Preset factory values of magnification were incorrect, resulting in errors in ECD of up to 9%. All assessments except 1 of the estimated ECDs differed significantly from manual ECDs, with most differences being similar (< or =6.5%), except for uncorrected IMAGEnet ECD (30.2%). Corrected IMAGEnet ECD showed the narrowest limits of agreement (-4.9 to +19.3%). CONCLUSIONS: We advise checking the calibration of magnification in any specular microscope or endothelial analysis software as it may be erroneous. Corrected IMAGEnet ECD is the most valid of the investigated methods in the Topcon SP-2000P/IMAGEnet 2000 combination.     

Age related differences in learning with the useful field of view

In naturalistic tasks, subjects often interact with a cluttered visual environment in which they need to divide their attention simultaneously among multiple objects and tasks. Previous work examining the effects of aging in tasks that approximate these real world demands have shown that performance often declines with age. For example, when subjects must perform central and peripheral visual tasks simultaneously in a Useful Field of View (UFOV) task, performance on the peripheral task declines relative to when subjects perform the peripheral task alone, and this divided-attention deficit grows decade-by-decade throughout our lifetimes [e.g., Sekuler, A.B., Bennett, P.J., and Mamelak, M. (2000). Effects of Aging on the Useful Field of View. Experimental Aging Research, 26, 103-120]. Here, we investigated the extent to which age-related differences in divided-attention could be overcome with practice. In addition, we assessed how divided attention costs varied when initial performance levels were equated across age groups at the start of practice. Experiment 1 determined the stimulus durations that approximately equated attentional costs for younger and older subjects. These stimulus durations were used in Experiments 2 and 3 to equate task difficulty across age. Experiments 2 and 3 examined the effect of practice for 1-2 weeks. Practice improved performance for both younger and older subjects, and, when older subjects were provided with enough practice, their attentional costs were equivalent to those of younger subjects. Indeed, with enough practice, both younger and older subjects reached a point where they showed no divided-attention deficits, although older subjects may need more practice to reach this point. Finally, the beneficial effects of practice were maintained for at least three months.     

Ganciclovir for the treatment of anterior uveitis

Background: Ganciclovir, administered systemically or intraocularly, is effective in controlling cytomegalovirus (CMV) retinitis in immunocompromised patients. The efficacy of therapy with this antiviral substance was investigated in an immunocompetent patient with CMV uveitis causing secondary glaucoma. Methods: To identify the presence of an intraocular viral infection, anterior chamber taps to detect the intraocular synthesis of IgG antibodies and PCR testing were carried out. Clinically, the degree of intraocular inflammation and the intraocular pressure (IOP) values were monitored. During this time, the patient was treated systemically with ganciclovir administered orally and intravenously. Results: The intraocular synthesis of IgG antibodies specific for CMV was found in two samples of aqueous humor, but negative for other viruses. PCR testing was negative for HSV, VZV and CMV at each time. During this time, the patient was treated systemically with ganciclovir administered either intravenously or orally. As a response to therapy with ganciclovir, the elevated IOP values decreased to normal and the intraocular inflammation declined. After cessation of ganciclovir administration, the inflammation and secondary glaucoma recurred. Conclusion: In this case of anterior uveitis presumably caused by CMV inducing secondary glaucoma, treatment with ganciclovir led to a decrease of the inflammation and normalization of IOP. It appears that continuous administration may be required to control the infection in an immunocompetent patient. Received: 17 February 2000 Revised: 11 May 2000 Accepted: 8 June 2000     

Exploring the time course of face matching: temporal constraints impair unfamiliar face identification under temporally unconstrained viewing

The identification of unfamiliar faces has been studied extensively with matching tasks, in which observers decide if pairs of photographs depict the same person (identity matches) or different people (mismatches). In experimental studies in this field, performance is usually self-paced under the assumption that this will encourage best-possible accuracy. Here, we examined the temporal characteristics of this task by limiting display times and tracking observers’ eye movements. Observers were required to make match/mismatch decisions to pairs of faces shown for 200, 500, 1000, or 2000 ms, or for an unlimited duration. Peak accuracy was reached within 2000 ms and two fixations to each face. However, intermixing exposure conditions produced a context effect that generally reduced accuracy on identity mismatch trials, even when unlimited viewing of faces was possible. These findings indicate that less than 2 s are required for face matching when exposure times are variable, but temporal constraints should be avoided altogether if accuracy is truly paramount. The implications of these findings are discussed.     

Indocyanine green and fluorescein hyperfluorescence at the site of occlusion in branch retinal vein occlusion

Background: In patients with branch retinal vein occlusion (BRVO), we investigated the presence of indocyanine green (ICG) and fluorescein hyperfluorescence at the site of occlusion. We also assessed the association of this feature with the clinical outcome of these patients. Methods: Both indocyanine green (ICG) videoangiography and fluorescein angiography (FAG) were performed in 21 eyes with BRVO of less than 1 month duration. Deterioration of the disease was defined clinically as an increase in retinal hemorrhages or retinal edema. Capillary nonperfusion was quantified with computer image analysis from the FAG pictures. Results: ICG videoangiography showed focal hyperfluorescence along the venous wall at the site of the affected A-V crossing in 9 of the 21 eyes, and FAG showed this feature in 10 eyes. The ICG hyperfluorescence was more prominently and focally detected than the hyperfluorescence on FAG, which was sometimes diffusely seen throughout the whole occluded area. Eight of the nine eyes showing ICG hyperfluorescence had clinical deterioration with an increase in retinal hemorrhage or edema. This deterioration occurred more frequently in eyes with hyperfluorescence and/or late leakage than in ones without these features. The mean nonperfused area was significantly larger in eyes with hyperfluorescence than in eyes without these features. Conclusion: The ICG hyperfluorescence at the site of A-V crossing is associated with disease deterioration in patients with fresh BRVO. The ICG hyperfluorescence was more easily detectable than the hyperfluorescence on FAG, although the difference in sensitivity between the two methods is not great. Received: 4 April 2000 Revised: 8 August 2000 Accepted: 29 August 2000