No abstract

The use of 95% ranges for TRV to establish the smallest measured visual acuity change that can be reliably detected ensures a high specificity but does not take account of sensitivity. Use of change criteria derived from published 95% ranges results in a sensitivity of approximately 50% (assuming identical levels of TRV). Sensitivity may be improved by using a change criterion that is smaller than the minimum change sought, providing the change criterion is still at least as large as the 95% range for TRV, so that specificity is maintained. Reducing TRV allows smaller changes in acuity to be reliably detected.

Background/aims-The advantages of logMAR acuity data over the Snellen fraction are well known, and yet existing logMAR charts have not been adopted into routine ophthalmic clinical use. As this may be due in part to the time required for a logMAR measurement, this study was performed to determine whether an abbreviated logMAR chart design could combine the advantages of existing charts with a clinically acceptable measurement time. Methods-Thetest-retest variability, agreement (with the gold standard), and time taken for "single letter" (interpolated) acuity measurements taken using three prototype "reduced logMAR" (RLM) charts and the Snellen chart were compared with those of the ETDRS chart which acted as the gold standard. The Snellen chart was also scored with the more familiar "line assignment" method. The subjects undergoing these measurements were drawn from a typical clinical outpatient population exhibiting a range of acuities. Results-The RLM A prototype chart achieved a test-retest variability of +/−0.24 logMAR compared with +/−0.18 for the ETDRS chart. Test-retest variability for the Snellen chart was +/−0.24 logMAR using clinically prohibitive "single letter" scoring increasing to +/−0.33 with the more usual "line assignment" method. All charts produced acuity data which agreed well with those of the ETDRS chart. "Single letter" acuity measurements using the prototype RLM charts were completed in approximately half the time of those taken using the ETDRS and Snellen charts. The duration of a Snellen "line assignment" measurement was not evaluated. Conclusion-The RLM A chart oVers an acceptable level of test-retest variability when compared with the gold standard ETDRS chart, while reducing the measurement time by half. Also, by allowing a faster, less variable acuity measurement than the Snellen chart, the RLM A chart can bring the benefits of logMAR acuity to routine clinical practice. (Br J Ophthalmol 2001;85:432-436)

This bleb grading system is reproducible clinically and photographically. High levels of agreement between scores for photographs versus slit lamp examination were found for most categories, with good interobserver agreement for both photograph and slit lamp grading. Further refinement of scoring and reference photographs is required for optimization, especially for grading of bleb morphology.

Sub-titleSelf-measurement using Icare Home showed good agreement with Goldmann applanation tonometry. Icare Home self-measurement was well accepted and reliable results obtained by 3 in 4 subjects, suggesting potential use for home measurement of intraocular pressure.

SummaryA study was conducted at the Moorfields Community Eye Clinic at Ealing Hospital to determine the positive predictive value (ppv) of optometric referrals for suspected glaucoma. The information reported in the referrals and the reasons given for referral were also assessed and evaluated in relation to the ppv. Information was gathered through prospective analysis of patient clinic notes. Ninety patients were referred over a six-month period of which 87 fulfilled the inclusion criteria. The optometrist referral letters for 79 of these patients were supplied by the GP. Results indicate a ppv of 0.43. The reason for referral in the majority of cases (48%) was raised IOP alone. However the most frequently reported mode of practice was a combination of disc and IOP assessment (57%). In line with other research our study demonstrates that referral accuracy improves as the number of suspicious findings increases. In addition those referrals reporting all three tests (IOP measurement, optic disc assessment and perimetry) are shown to have the highest ppv.

Purpose: In the UK, the majority of cases of chronic open angle glaucoma are detected by community optometrists following a routine sight test. However, there is potential for variability in case finding strategies used. The aim of this study was to carry out a national web-based survey to determine current diagnostic tests used by optometrists in glaucoma case finding. Methods: Optometrists on the Association of Optometrists (AOP) electronic database were invited to participate. The survey was open for 16 weeks between April and July 2008. Results: A total of 1875 optometrists were eligible to enter the survey, of which 1264 answered the questions relating to diagnostic equipment. Respondents were asked to indicate their usual method of examining the optic nerve head. Direct ophthalmoscopy only was used by 25% with the majority (62%) using a combination of direct and slit-lamp binocular indirect methods. The vast majority of optometrists (78%) used non-contact tonometry to measure intraocular pressure, with only 16% routinely using a Goldmann or Perkins applanation tonometer. The perimeter most frequently used was either one of the Henson range of instruments (39%) or the Humphrey Field Analyser (22%). A smaller number of optometrists (<5%) had access to more specialised imaging equipment, such as HRT, GDx or OCT. Conclusions: The results of the survey demonstrate that UK optometrists are well equipped to carry out case finding for chronic open angle glaucoma, although there is a lack of standardisation with respect to equipment used.

Beta radiation has a long history as a treatment modality in ophthalmology. It is a convenient and practical method of applying radiation and has the advantage of minimal tissue penetration. There has been a recent resurgence in the use of beta radiation in other areas in medicine, such as the prevention of restenosis after coronary artery stenting. Beta radiation has been shown in vitro and in vivo to inhibit proliferation of human Tenon's fibroblasts, which enter a period of growth arrest but do not die. Effects on the cell cycle controller p53 have been shown to be important in this process.In ophthalmology, beta radiation has been used widely for the treatment of pterygium and is under evaluation for treatment of agerelated macular degeneration and for controlling wound healing after glaucoma drainage surgery. In this latter role, beta radiation may be particularly appropriate for use in developing countries to improve the results of trabeculectomy while potentially avoiding some of the side effects of other antimetabolites.