The Access To Work scheme is a UK government-funded work scheme that can help your business and your employee if his or her retinitis pigmentosa affects the job.
The scheme is designed as a trusted source of advice for both of you. Importantly, it also provides financial support towards extra work costs which may arise, for example to provide transport, a support worker, special computers or other equipment. In some cases it can also contribute to the cost of commuting.
Rather than duplicate information here, please follow this link to the Direct.Gov internet pages about the scheme. Bear in mind also that such government-funded schemes are subject to change.
You should ensure that your employee is aware of the scheme and your willingness to work together to secure the support you are both entitled to.