PurposeA handheld device (the RETeval system, LKC Technologies) aims to increase the ease of electroretinogram (ERG) recording by using specially designed skin electrodes, rather than corneal electrodes. We explored effects of electrode position on response parameters recorded using this device.MethodsHealthy adult twins were recruited from the TwinsUK cohort and underwent recording of light-adapted flicker ERGs (corresponding to international standard stimuli). In Group 1, skin electrodes were placed in a “comfortable” position, which was up to 20 mm below the lid margin. For subsequent participants (Group 2), the electrode was positioned 2 mm from the lid margin as recommended by the manufacturer. Amplitudes and peak times (averaged from both eyes) were compared between groups after age-matching and inclusion of only one twin per pair. Light-adapted flicker and flash ERGs were recorded for an additional 10 healthy subjects in two consecutive recording sessions: in the test eye, electrode position was varied from 2 to 10–20 mm below the lid margin between sessions; in the fellow (control) eye, the electrode was 2 mm below the lid margin throughout. Amplitudes and peak times (test eye normalised to control eye) were compared for the two sessions.ResultsIncluding one twin per pair, and age-matching yielded 28 individuals per group. Flicker ERG amplitudes were significantly lower for Group 1 than Group 2 participants (p = 0.0024). However, mean peak times did not differ between groups (p = 0.54). For the subjects in whom electrode position was changed between recording sessions, flash and flicker amplitudes were significantly lower when positioned further from the lid margin (p < 0.005), but peak times were similar (p > 0.5).ConclusionsMoving the skin electrodes further from the lid margin significantly reduces response amplitudes, highlighting the importance of consistent electrode positioning. However, this does not significantly affect peak times. Thus, it may be feasible to adopt a more comfortable position in participants who cannot tolerate the recommended position if analysis is restricted to peak time parameters.

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Purpose: To describe and evaluate demographic, clinical features, prognostic factors, and rate of success of surgery and visual outcomes in patients with late presentation of retinal detachment. Methods: A retrospective, comparative, observational case series of patients with late presentation retinal detachment, defined as retinal detachment with the loss of central vision for 4 weeks or more, over a period of 12 months. Results: The mean of onset of central visual loss was 12.7 weeks (SD, 21.3). Proliferative vitreoretinopathy at the first operation was identified in 69% of eyes. The overall primary success rate was 69.2%, significantly less than that was found in outcomes for nonselected retinal detachment (primary success rate, 86%; P = 0.006). The initial best-corrected visual acuity was 20/500, and the final was 20/160 (P = 0.0027). There were no identifiable statistically significant socioeconomic factors related to late presentation. Conclusion: A high rate of established proliferative vitreoretinopathy on presentation was identified, and although cases can be treated with good anatomical results, visual outcomes are often less favorable. Primary surgical success is lower, and more reoperations are required compared with standard retinal detachments.