[Closed-circuit television systems : Current importance and tips on adaptation and prescription]

Visual rehabilitation of patients with corneal diseases

BACKGROUND

Although most patients with visual impairment due to corneal diseases can be treated successfully with surgery, some require visual rehabilitation to restore reading ability. To evaluate the best LVAs especially in terms of reading speed and characterize this specific patient group we performed a prospective, randomized cross-over trial.

METHODS

All 34 patients underwent a detailed examination (slit-lamp, funduscopy, SD-OCT, ETDRS) as screening. Only patients with corneal diseases without other ocular diseases were included. Reading-speed was assessed with International-Reading-Speed-Texts (IReST) consecutively with five different LVAs (low vision aids) during one day in a randomized cross-over design. Corneal haze was quantified with corneal densitometry (Pentacam).

RESULTS

Patients were either visually impaired (n = 28), severely impaired (n = 4) or legally blind (n = 2). Patients read significantly faster with LVAs (p < 0.0001). Fastest reading speed could be achieved with video magnifier (CCTV). Optical magnifier and portable-electronic magnifier enabled significantly lower reading speeds (p < 0.01). In a subgroup of patients (VA < 3/60,n = 6) black background enabled patients to read significantly faster compared to white background (p = 0.03).

CONCLUSION

Patients with low magnification requirement can be treated successfully with optical LVAs and portable-electronic magnifiers. More severely afflicted patients need a CCTV. Black background enables fastest reading-speeds, probably due to less blinding. Visual impairment can be estimated with corneal densitometry. Our trial confirms the capability of LVAs to successfully restore the reading ability in patients with corneal diseases, which is a crucial part of visual rehabilitation.

TRIAL REGISTRATION

This trial was registered at the German Clinical Trials Register as DRKS00010887 at 09.08.2016.

The assistance of electronic visual aids with perceptual learning for the improvement in visual acuity in visually impaired children

PURPOSE

To investigate the effect of electronic visual aids (EVA) combined with perceptual learning (PL) for the improvement in visual acuity for moderate to severe visually impaired and blind children.

METHODS

Twenty-eight 6- to 14-year-old visually impaired children (19 boys and 9 girls) were divided into two groups: PL under the assistance of EVA (Group A, 14 children) and simple PL without EVA (Group B, 14 children). The content of PL was to search the inversed "E" in the crowding strings and connected with lines, 30 minutes a day for 6 months. EVA can provide 5-10 times magnification on the 4.3-inch screen. Uncorrected distance visual acuity (UCVA), best-corrected visual acuity (BCVA), near visual acuity (NVA) and refractive error were evaluated before and 3 and 6 months after training.

RESULTS

Baseline UCVA, BCVA or NVA was comparable between the two groups. Three months after training, UCVA, BCVA and NVA improved significantly in Group A (p < 0.05). At the end of training, UCVA and BCVA continued progressing in Group A compared to 3 months (p = 0.01, 0.02), but visual acuity did not show significant improvement in Group B during the same time, except that UCVA improved at the first follow-up. Refractive error had no significant change post-training in both groups.

CONCLUSIONS

Visually impaired children can benefit more from the combination of PL with EVA than simple PL, and the improvement in visual acuity accompanied no significant myopic shift. It may provide a new method of treatment and rehabilitation in visually impaired children.