Abstract Aim: To use previously validated image analysis techniques to determine the incremental nature of printed subjective anterior eye grading scales. Annunziato and Efron pictorial, and CCLRU and Vistakon-Synoptik photographic grades of bulbar hyperaemia, palpebral hyperaemia roughness, and corneal staining were analysed. Results: The increments of the grading scales were best described by a quadratic rather than a linear function. Conclusion: The printed grading scales were more sensitive for grading features of low severity, but grades were not comparable between grading scales. Palpebral hyperaemia and staining grading is complicated by the variable presentations possible. Image analysis techniques are 6—35 times more repeatable than subjective grading, with a sensitivity of 1.
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In order to improve and standardise anterior eye evaluations between practitioners, subjective grading scales were first popularised back in the mids. Benefits of Grading Scales The benefits of clinical grading scales include accuracy and consistency in clinical record keeping leading to more meaningful communication of clinical cases to fellow health professionals.
Clinical grading scales also offer practitioners the most effective way of monitoring the health of an eye wearing a contact lens. They allow for an accurate means of detecting change that can occur during lens use and provide the practitioner with the necessary information to intervene to minimise the risk of a chronic adverse reaction to the contact lens.
Table 1 summarises the benefits. Ideally, prior to contact lens wear, the baseline data for a range of clinical variables should be collected and then be continually monitored throughout the course of the patients wearing experience. The latter consists of a series of artist illustrated depictions of 16 different conditions, while the former comprises photographs of 6 conditions, two of which are presented in multiple manifestations.
Figure 2: Efron scale The BHVI photographic scales have been criticised for the lack of perfect homogeneity between images representing the same condition, either in terms of different illumination conditions or variability of size of the area under display. Whilst Efron overcomes these difficulties by encouraging artistic clarity and licence so as to emphasise and isolate the condition that is being evaluated, it is considered by some a departure from the real life situation in as much as different conditions feed and depend on each other and, therefore, occur simultaneously and should appear as such in a single image.
Both clinical grading scales have been published in prominent textbooks and widely distributed around the world, free of charge, by several major contact lens companies. Indeed it is estimated that over , copies of these scales — usually in the form of laminated A4 reference cards but also in large poster format — have been provided to practitioners in the past 20 years.
More recently, other clinical grading scales have been introduced see Figure 3 Figure 3: Examples of more recently introduced grading scales Repeatability Researchers have examined the repeatability of discrete and continuous anterior segment grading. They conclude that grading scales that are too coarse generally allow less sensitivity in the detection of meaningful clinical changes.
Practitioners often overcome this limitation by adopting half-point scales, or by assigning plus and minus symbols next to an integer scale. They also believe that increasing the number of intervals to make the grading scale finer may reduce the degree of concordance between repeated measurements of the same clinical event. Finer scales have the advantage of being capable of recording clinical change more sensitively. By grading to decimal places that are representative of points in between two successive integer points on the scale, 1.
However, there is a limit to such interpolation; 0. The variability of grading scores between practitioners can be wide and they generally tend to form clusters around whole numbers. Evidence suggests that concordance tends to improve with training or practice.
Another concern with existing clinical grading scales is that they do not cover all possible clinical appearances, particularly at the severe end of the scale, and that they may not be linear.
Objective analysis of digital images provides an attractive alternative to the current subjective nature of practitioner grading, and this has the potential to be more sensitive. The subjective judgement that a practitioner makes at the slit lamp is however a complex one to mimic objectively.
The objective grading of ocular redness involves judgement of both the hue and vessel size, relative to the area under question. This is difficult for software to achieve accurately. Approaches to this challenge are still emerging and further developments in this area are anticipated. Figure 4: Computerised grading — note the slider at the bottom of the screen allowing easy adjustments of severity Computerised grading removes the problem of grading between ratings.
This may involve the use of movie sequence of images, a CD for the Efron gratings, a phone app, or computer software programs. The app enables levels of severity to be compared side-by-side in 0. A report can then be exported for practice records without collecting patient personal data. Figure 5: A modern grading scale adapted for smartphone use Nowadays, many practitioners record clinical information electronically by entering data into defined fields within computer-based clinical management software programs — a practice that in effect prompts practitioners to capture all relevant aspects of the presenting signs and symptoms.
For example, there may be specific fields for each eye, separate fields for slit lamp findings and previously drawn sketches of the eye, over which text or drawings can be interposed.
Paper records may also have specific sections for recording clinical information, as well as previously drawn ocular sketches for annotation. Practitioners who use photography to document complications admit, in many cases, to also use grading scales. This duplicitous practice represents a conservative approach to record keeping and suggests that many practitioners consider the recording of clinical grades and clinical photography to be complementary approaches.
What can we do to improve clinical grading? Individually, our grading is repeatable, so we should continue to use the scales in the way we are doing now. What we are not that good at, however, is being consistent with our colleagues. If we are working in settings where patients are being seen by multiple practitioners, it is critical that the same scales be used and the same rules applied, to ensure that numbers assigned to appearance by different practitioners match.
Grading scale grades are not interchangeable, with scales starting either at grade 0 or 1 and with a wide range of values for the highest grade. Practitioners must record the grading scale used, and ideally standardise this within an individual practice or corporate groups.
Table 2 summarises some key points to consider. Two important recent studies help us to reach a more standardised approach. Word description, sketches and grading scales were used more for recording the anterior eye health of contact lens wearers than other patients, but photography was used by a similar number. Description, sketches and grading scales were used more for recording the anterior eye health of contact lens patients than other patients, as was photography. Figure 6: Grading scales used Most practitioners graded to the nearest whole unit The average time taken to record anterior eye health was 6.
Figure 7: Increments of scales used The study reached a number of important conclusions summarised in Table 3. A second study was by Efron et al. The response rate was 31 per cent. Conclusions of this second study were that optometrists grade a diverse array of anterior eye conditions, the three ocular conditions that were found to be the most frequently graded were corneal staining, papillary conjunctivitis and conjunctival redness.
This is perhaps not surprising, given that these are common complications often related to patient symptoms and also the subject of extensive discussion in the literature and at conferences. Another interesting finding was that grading scales are more likely to be used by optometrists who have recently graduated, have a postgraduate certificate in ocular therapeutics, see more contact lens patients or use other forms of grading scales.
The primary reason cited for not using grading scales was a preference for recording clinical data using other means, such as sketches, photographs or written descriptions. These alternative approaches to record keeping can all be considered as representing good clinical practice. The view expressed by a small minority of optometrists was that grading scales constitute an unreliable or inaccurate method of recording clinical data is contrary to published evidence.
Included in the improved version will be high definition images and compatibility with iPads as well as iPhones. Lens Anterior Eye. Caroline Christie is an independent optometrist specialising in contact lenses.
Deciphering Corneal Staining Scales
Corneal staining is a valuable clinical tool for assessing corneal epithelial integrity at the slit lamp. Recent reports of clinically significant corneal staining with silicone hydrogel lenses have highlighted the importance of understanding the interaction of lenses, lens care solutions and the corneal surface. Understanding these relationships and integrating the study findings into the current body of knowledge requires comparable data from multiple studies. This is difficult to achieve when investigators use different patient populations, different scales to generate staining scores and different benchmarks for staining intensity and clinical severity.
Efron Grading Scales
The primary reason cited for not using grading scales was a preference for recording clinical data using other means, such as sketches, photographs or written descriptions. Clcru and Efron pictorial, and CCLRU and Vistakon-Synoptik photographic grades of bulbar hyperaemia, palpebral hyperaemia roughness, and corneal staining were analysed. Variability of clinical researchers in contact lens research. Am J Ophthalmol ; Palpebral hyperaemia scale images were well described by colour extraction techniques. Colour extraction has face validity 28 and examines global relative colouration red for hyperaemia and green for staining.