Quantitative Slit Lamp Observations in Contact Lens Practice

Aftercare of the contact lens wearing patients is very difficult without an adequate means of evaluating change. Descriptive terms, as used by mostpractitioners, to record slit-lamp observations allow flexibility for the variety of clinical presentations. Analysis of clinical observations, the evaluation of changes in ocular structure or condition after contact lens wear, is difficult with only qualitative terms. Semantic (language dependent) difficulties inherent in, often highly individualistic and stylistic, qualitative patient records, may result in poor interpretation of clinical findings at aftercare. Combined with the lack of systematic recording of observations, inappropriate clinical decision making may result. Quantitative (numerical) records are important for experimental and clinical analysis, to avoid these problems. Routine use of a grading system for clinical data collective allows for greater reliability (same result for the same observation), is systematic (logical ordering of observations), semantically independent (not subject to the same degree of interpretation), and analytical (allow quantitative assessment of change at subsequent examination). A recording system is proposed which, when used in conjunction with clinical diagrams, lends itself to simplicity, yet high information content, to enhance and aid clinical decision processes. It is important to keep logical, intelligible patient records, which detail all procedures, results and management decisions. Ethically the practitioner must act in the best interest of the patient, and good aftercare of contact lens patients is very difficult without an adequate means of evaluating change. In addition, patient records are legal documents, and in the event of a case of negligence, a procedure not recorded, in the eyes of the law, was not performed. Taylor and Austen (1986) outline the “minimum contents” and “essential elements” of case records (pp168-171). Slit lamp observations in contact lens practice are those of the anterior eye and contact lens, but the topics discussed here can be generalised to many aspects of optometric and ophthalmic practice. Aftercare of the contact lens patient may be considered the assessment and management of ocular and contact lens condition after commencement of wear. The General Optical Council requires that practitioners provide “adequate continuing aftercare and supervision” (Notice N.22). Supervision requires patient management decisions involving clinical assessment of change, which can only be made with sufficient information regarding the previous ocular and contact lens condition. Managemnt includes: regular monitoring; alterations in wearing schedule, lens maintenance regimen or fitting philosophy; and medical intervention. Many practitioners recording slit-lamp observations use descriptive or qualitative terms. Qualitative terms are very flexible and allow the practitioner to cope with the wide variety of clinical presentations. The inherent difficulty, however, is that such recording is dependent upon the vagaries of language. Words are semantically ambiguous various interpretations may be made of the same word, both in time and between practitioners, leading to difficulties of interpretation at subsequent examination of the patient. The use of qualitative terms can be highly subjective, resulting in poor reliability. In addition qualitative records are non-systematic, and therefore not in a form which can be used readily for data collection or analysis. Analysis includes normal aftercare of a contact lens patient in the evaluation of changes in structure or condition. Information collected in this form cannot be used within an experimental context as the data cannot be entered into a computer and used for analysis or calculation. A quantitative recording system offers many advantages, including simplicity. Although modifying established procedures may not strike the experienced practitioner as a ‘simple matter, I shall endeavour to demonstrate the benefits and ease of applying such a system. Quantitative recording of clinical findings is more reliable, systematic (i.e logically orders observations), semantically independent and analytical,