Redesigning services for the management of vitreomacular traction and macular hole.

Vitreomacular traction (VMT) and VMT with macular hole (MH) are serious conditions, being associated with visual disturbance, for example, metamorphopsia, and diminished visual acuity (VA). Pars plana vitrectomy is the routine treatment for symptomatic VMT and VMT+MH. However, ocriplasmin has demonstrated favourable efficacy and safety in specific patient groups with VMT/MH and is now recommended as a treatment option for certain patients by the National Institute of Health and Care Excellence. This means that services for managing patients with VMT/MH may need to be revised, as patients can now potentially receive treatment earlier in the course of the disease. VMT triage clinics could provide a more efficient way of managing VMT/MH patients. Patient assessment should always include high-definition optical coherence tomography, as this is the most accurate means of assessing abnormalities in the vitreoretinal (VR) interface, and an accurate measurement of best-corrected VA. It has been proposed that patients with VMT+MH be managed as a routine 6-week referral, with the complete patient journey-from initial referral to treatment-taking no longer than 6 months. It is important that patients are entered onto VR surgical lists so that there is no delay if ocriplasmin treatment is unsuccessful. Patients will need appropriate counselling about the expected outcomes and possible side effects of ocriplasmin treatment. One-year follow-up data should be collected by treatment centres in order to evaluate the new VMT service.

New range of stand magnifiers based on standardized image position.

Combined Optical Industries Ltd. of Slough, UK, have released a new range of illuminated stand magnifiers. These have been designed with a uniform emerging vergence and are specified in terms of equivalent power according to the new standards. This paper describes these magnifiers in terms of their measured optical and ergonomic properties. The expected enlargement ratios achieved with typical presbyopic additions are tabulated.

Using visual thresholds to establish low vision performance.

Table 6 gives an example of a similar task (N10 print of 75% contrast) but with different requirements of fluency showing how much extra visual performance (acuity threshold, contrast threshold and magnification) is needed to achieve fluent reading. After the clinical assessment of visual function, it should be possible to categorize clients into three different groups on the basis of their threshold visual performance, each needing a different approach depending on their goals and needs as shown in Table 7. These are: Group I: Limited or no survival reading potential. Group II: Survival reading potential but limited likelihood of fluency. Group III: Clear survival reading potential with fluent reading possible if motivated. The author believes that it is always best to start with what the client has to read in order to maintain their independence, rather than what they wish to read for leisure, education or employment. Therefore, it is more successful to concentrate initially on spot/survival reading even if the client seems to have potential for regaining fluency. It should, however, be made clear to the client that this is the approach to be adopted. It is futile for the practitioner, as well as frustrating and demoralizing to the client, to press ahead with complex devices or wasteful trial and error sessions if, at an early stage, it is clear that the client will never return to fluent reading. Instead, it is far better to begin the move to vision substitution (e.g. audio-tapes) for leisure reading at an earlier stage. The overriding influence in low vision management is clearly the motivation of the client.(ABSTRACT TRUNCATED AT 250 WORDS)

The aging eye and vision appliances.

This paper describes some of the potential impact the aging population may have on routine optometric practice from the perspective of the aging normal patient as opposed to the low vision patient. The significance of social aspects, criteria for change and the importance of effective communication are emphasised. The implications of the major aging diseases (stroke, Parkinson's disease and Alzheimer's disease) on the optometric examination is included.

The experience of a university-based low vision clinic.

An open low vision clinic has been in operation at University of Wales College of Cardiff, Department of Optometry for 5 years. This paper describes the demography and visual characteristics of 218 consecutively presenting patients. A detailed survey of the aids prescribed is conducted. A significant proportion of low vision patients required only simple aids (56.8%) and low magnification (71.6%). It is suggested that these patients could be assisted in an optometric practice. In addition, visual acuity, distance or near is not a good indicator of eventual visual performance with an LVA. Therefore, it was concluded that all patients having measurable form vision should receive a low vision assessment.

Modulation transfer functions of low-vision AIDS: comparison with spatial-frequency requirements in low vision.

Modulation transfer functions (MTF's) of 26 low-vision aids (LVA's) were measured by using the EROS solid-state system. The object and image distances of the LVA's were as in normal usage by a patient. The contrast thresholds of patients who use LVA's were also measured. All LVA's measured have more than adequate contrast transmission at the low frequencies that are important for these subjects, but many have wasted transmission at medium and high frequencies. LVA's with poorer high-frequency MTF can be used successfully by low-vision patients. It is suggested that in future design high resolution should be sacrificed for a greater lens diameter while maintaining a high MTF at low spatial frequencies.

Outcome of low vision aid provision: the effectiveness of a low vision clinic.

PURPOSE: Although there is an increasing need for primary low vision (LV) care, few studies have considered the success rates of optometric LV rehabilitation. We considered the objective success and perceived benefit obtained by 57 elderly LV patients. METHOD: Tests of reading speed and questionnaires were administered in the patient's home after initial and follow-up visits to a LV clinic. Additional information was taken from the patient's clinic record. RESULTS: Benefits from attending the clinic were reported by 89.5% of patients and 81% of patients were regularly using low vision aids (LVA's). There was a discrepancy between ability to read 1M print in the clinic (75% of patients) and the reported ability to read regular-sized print at home (35%). Perceived benefit from visiting the clinic was strongly associated with the ability to perform daily living tasks and to read 2M print. There was some association between perceived benefit and frequency of using the LVA's, but not with duration of use. CONCLUSION: The results encourage a change in emphasis during LV assessments from sustained reading to the ability to perform daily living activities.