COMPlog

Acuity measurements are fundamental to ophthalmic, optometric and orthoptic practice. Clinicians want precise and reliable acuity measurements with which to diagnose disease or detect change. However, a combination of chart, patient, tester and scoring factors mean that acuity measurements are frequently imprecise, unreliable and therefore of dubious clinical value.

COMPlog is a great solution to this problem!

Unlike other systems COMPlog is not just a computerized test chart. It is a semi automated computerized vision measurement system. It has been designed to produce a precise logMAR and Snellen visual acuity score. In addition to acuity measurement COMPlog provides full refraction and orthoptic test support. As well as automating the acuity measurement process COMPlog allows acuities ranging from 1/60 to 6/3 to be measured from one testing distance. There are multiple published studies documenting the validation of this unique system.

No more logMAR bingo! Accurate logMAR visual acuity testing made easy!

Designed from an ergonomic viewpoint the tests are run through a series of simple mouse clicks or touch screen controls. There are no fiddly infra red remotes controls to battle with or lose. The test proceeds through one of a controllable variety of automated test sequences. The major input is whether the presented letter(s) has been correctly or incorrectly identified. Various different test optotypes are available (Sloan, VOTH, Sheridan Gardner, Landholt C, Tumbling E and Kay Pictures). Other letter sets and test optotypes can be incorporated as required.

The hardware consists of a desktop or laptop PC running a standard primary monitor and a secondary monitor which the patient views. The test results are automatically calculated and presented in any combination of required Snellen and logMAR formats. Test results can be printed, stored on a COMPlog network database or integrated seamlessly into an Electronic Medical Record.

The user just has to click ‘correct’ / ‘incorrect’ according to the patient’s responses.

COMPlog Acuity tests

COMPlog offers two different acuity testing approaches, both of which can be further modified:

• COMPlog Acuity Thresholding
• Test Chart Thresholding

COMPlog Visual Acuity Thresholding

This is a quick and accurate measure of a patient’s VA. The patient is presented with single, crowded letters until they can no longer identify the letter correctly.

At this point, the patient is presented with a line of letters at their lowest threshold. The patient then identifies each letter individually.

The user just has to click ‘correct’ or ‘incorrect’ to score the patient’s VA, which is presented in all common notations. The VA is plotted for each eye as a graph so the user can easier visualise the patient’s progression.

The test algorithm is completely controllable. The number of letters per line, the letter set and line pass or fail criteria can all be varied by the user. This allows testing to be varied from a quick rough-and-ready measure to a slower testing stratagem that delivers a very precise visual acuity result. A further feature is the calculation of a mean acuity from a series of tests. This provides acuity measurements which are more precise and reliable than can be obtained using gold standard ETDRS chart measurement techniques.

When interfaced with Medisoft or any other Electronic Medical Record, the visual acuity scores can be automatically exported to the patient’s record.

COMPlog Acuity Chart

COMPlog Acuity Chart allows a rapid vision to be recorded – the user can just click on individual lines to highlight them for the patient to read.

COMPlog provides a complete solution as it also incorporates refraction and orthoptic test support. Again a touch screen or mouse clicks control the tests which can be easily and rapidly changed. Users can also jump in and out of the refraction module when performing acuity thresholding, thereby providing ergonomic support for optometric refraction and acuity measurements. Tests offered include Duochrome, Fan and Block, moving animations, fixation targets, fixation disparity and UK number plates. Other tests could be incorporated on demand.

Future Developments

Low contrast acuity, stereopsis and colour vision testing are undergoing development and validation.

Reference

1. Computerised Repeating and Averaging Improves Upon Current Gold Standard Visual Acuity Change Detection. Shah N, Laidlaw DA, Shah SP, Sivasubramaniam S, Carbonaro F, Bunce C, Cousens S. Submitted to IOVS 2010

2. Validation of Computerised and printed Kay Picture logMAR Tests Shah N, Laidlaw DA, Khan S. Submitted to Ophthalmic and Physiological Optics 2010

3. Validation of a computerised logMAR visual acuity measurement system (COMPlog): comparison with ETDRS and the electronic ETDRS testing algorithm in adults and amblyopic children. Laidlaw DA, Tailor V, Shah N, Atamian S, Harcourt C. Br J Ophthalmol. 2008 Feb;92(2):241-4.

4. Effect of letter separation on computerised visual acuity measurements: comparison with the gold standard Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Shah N, Laidlaw DA, Brown G, Robson C. Ophthalmic Physiol Opt. 2010 Mar;30(2):200-3.

5. Development of a clinically feasible logMAR alternative to the Snellen chart: performance of the “compact reduced logMAR” visual acuity chart in amblyopic children. Laidlaw DA, Abbott A, Rosser DA.. Br J Ophthalmol. 2003 Oct;87(10):1232-4.

6. Evaluating a new logMAR chart designed to improve visual acuity assessment in population-based surveys. Bourne RR, Rosser DA, Sukudom P, Dineen B, Laidlaw DA, Johnson GJ, Murdoch IE. Eye (Lond). 2003 Aug;17(6):701-6.

7. Improving on ETDRS acuities: design and results for a computerised thresholding device. Rosser DA, Murdoch IE, Fitzke FW, Laidlaw DA. Eye (Lond). 2003 Aug;17(6):701-6.

8. How sensitive to clinical change are ETDRS logMAR visual acuity measurements? Rosser DA, Cousens SN, Murdoch IE, Fitzke FW, Laidlaw DA. Invest Ophthalmol Vis Sci. 2003 Aug;44(8):3278-81.

9. The development of a “reduced logMAR” visual acuity chart for use in routine clinical practice. Rosser DA, Laidlaw DA, Murdoch IE. Br J Ophthalmol. 2001 Apr;85(4):432-6

IP in COMPlog

The IP in COMPlog is owned by Guy’s and St. Thomas’ Hospital NHS Foundation Trust. Medisoft markets COMPlog on behalf of the owners of the product.