Table 1

Characteristics of included studies

Study	Method	Participants	Intervention	Outcome measures	Effect	Remarks
exp, experimental; HRP, High- resolution perimetry; Ich, intracerebral haemorrhage; Inf, infarction; LH, left-sided hemianopia; OD, right eye; OS, left eye; VRT, vision restoration therapy; VEP, Visual evoked potential; plac.,placebo; RCT, randomised controlled trial; RH, right-sided hemianopia; rm, repeated measures; RMD, repeated-measures design; S, significant; SLO, scanning laser ophthalmoscope; TAP, Tübinger automatic perimeter.
VRT
Reinhard et al (2005)¹³	RMD study	17 patients, time after onset: >1 year, lesion location in central visual pathways	VRT: Nova Vision, 6 days a week, 60 min sessions, length of intervention 6 months	Objective	Objective	Pathology heterogeneous
	rm: 2	Mean age: 49 (range 24–72) years	Fixation control: no	SLO difference of ratio before and after training = E, 0.14E = 1 degree	SLO: no increase in border shift	Outcome not comparable with other studies, no comparison between SLO and HRP/TAP
	Before training		Head and eye movements: no	ADL: text presented in the SLO, reading speed, wpm	ADL: reading speed: 6% improvement: not relevant	No correlation of objective results with subjective reports, no clear data
	After training				Subjective	Good internal validity
	No follow-up			Subjective	2/3 satisfied with training
				Reports of patients	6 satisfied with reading; 4 not satisfied, 4 no reading problem before training
Sabel et al (2004)¹⁴	RMD study	16 patients, post hoc 2 groups, COM (n = 9) and INC (n = 7), time after onset: >1 year, lesion location	VRT: Nova Vision, 6 days, twice a week, 30 min sessions, length of intervention 6 months	Objective	Objective	Pathology: heterogeneous
	rm: 2	Post-chiasmatic	Fixation control: no	SLO difference of ratio before after training = E, 0.14E = 1 degree	SLO: no increase in border shift	Efficacy of VRT depends on which outcome measure is used
	Before training	Mean age: 49.3 (range 24–72) years	Head and eye movements: no	HRP, number of hits	HRP: 5.28–7.01° (0.20°) increase in border shift	Subjective: reading: no clear data
	After training			TAP, number of misses	HRP and TAP: OD 4.56–6.05° (0.20°); OS 4.49–5.47° (0.21°) increase in border shift	No relationship between improvement in perimetric procedures and subjective vision
	No follow-up			Subjective:
				Standardised vision state questionnaire	Subjective:	Good internal validity
				Vision change questionnaire	87.5% satisfied with VRT
				Reports of patients	Vision state questionnaire: 10% improvement
					Vision change questionnaire: 14/15 patients improved
Julkunen et al (2003)⁶	RMD study	5 patients, time after onset: >1 year, lesion location	VRT: developed computer program training, 3 times a week, 60 min sessions	Objective	Objective:	Pathology: homogeneous
	rm: 3	Left occipital inf 1	Length of intervention: 33–47 h (3–4 months)	Kinetic: Goldmann, degrees	Perimetry: yes, VEP: yes	Detailed description of patients
	Before training	Left occipital ich 1	Fixation control: yes	Static: Octopus101, degrees		No clear data of objective outcome measures and subjective data of reading
	After training	Right temporal ich 1	Head and eye movements: no	VEP, latency in ms	Subjective improvement 2, decline 2, no change 1	No general conclusions due to small group
	After follow-up	Left multiple ich 1		Subjective questionnaire		Moderate internal validity
	Follow-up period: 3 months	Right temperooccipital inf extending to thalamus:1
		Age: 18–70 years
Kasten et al (2001)⁵	Randomised trial double blind	22 patients, exp. group (n = 16)	VRT: exp. group: Visure, Seetrain, plac. group: Fixtra, daily, 60 min sessions, length intervention 150 h within 6 months	Objective	Objective	Pathology: heterogeneous
	Follow-up study RCT 1998	Plac group (n = 6), time after onset: >1 year, lesion location	Fixation control: yes	PeriMa, number of stimuli; PeriForm, number of forms; PeriColor, number of colours; TAP, number of hits and misses	Mean (SD) exp.group increase 0.4 (0.9°), plac. group increase 0.13° (0.6°)	Different outcome measures and VRT in comparison with pretreatment and post-treatment periods (Kasten, 1998); hence incomparable with data before- and after training
	Follow-up period:	Post-chiasmatic-optic nerve	Head and eye movements: no	Subjective		No blinding of participants
	Mean (SD) 23.5 (2.3) months	Mean age		Questionnaire	Subjective	No subjective data from this study
		Exp. group 47.7 (12.9), plac. group 55.3 (range 16.2)			From study 1998	< poor internal validity >
Kasten et al (1998)⁴	Two randomised controlled trials	46 patients	VRT exp. group: Nova Vision, plac. group: fixation training programme,	Objective	Objective	Pathology heterogeneous
	1. Optic nerve	Exp. group (n = 18)	daily, 60 min sessions, length intervention 6 months.	Primary: HRP,	Primary: improvement	Subjective measures: no separate outcome measures optic nerve lesion and postchiasmatic
	2. Postchiasmatic	Plac. group (n = 30), time after onset: >1 year, lesion location	Fixation control; no	Secondary: TAP	Exp HRP: 29.4% border shift 4.9° (1.7), placebo HRP: 7.7%	< good internal validity>
	included: postchiasmatic trial	Post-chiasmatic and	Head and eye movements: no	Subjective	Border shift −0.9° (±0.8)
	No follow-up	Optic nerve		Pre-trial: history interview	Secondary: improvement
		Mean (SD) age		Post-trial: questionnaire	Exp TAP border shift 0.43° (0.34)
		Exp group 47.7 (12.9), plac. group 55.3 (16.2)			Placebo TAP −0.51° (0.34)
					Subjective improvements:
					Exp 72.2%, placebo: 16.6%
Kasten et al (1995)⁸	RMD study	14 patients, time after onset: 0.5–240 months, lesion location:	VRT Visure, Seetrain, Formtrain, daily, 60 min sessions, length intervention 80–300 hours.	Objective	Objective	Pathology heterogeneous
	rm 2	Post-chiasmatic.	Fixation control: no	Static perimetry:	Improvement:	Specific training effect light, form and colour: modality specific
	Before training	Mean age 48.5	Head and eye movements: no	Perimat	Perimat: 41.6% in 9 of 11 patients	Within first 20 hours no training effect, increase effect from 30 hours
	After training			Periform	Periform: 37.4%, depending on hours of training	< moderate to poor internal validity>
	No follow-up			Pericolor:	Pericolor: 25.7%
				Dynamic: TAP	TAP: unclear
				Subjective
				None
Balliet et al (1985)¹²	RMD study	12 patients, time after onset: 5–36 months, lesion location:	VRT Goldmann perimeter, compensation training for patients who failed VRT: Goldmann,	Objective	Objective:	Pathology homogeneous
	rm 2	Occipital.	2–5 days weekly, 60 min sessions, length intervention	Goldmann perimeter	Restitution: Goldmann perimeter: 1°	Used same instrument for test and training (Goldmann), bias on training effect
	Before training	Age: 56–66	2–11 months.	Subjective:	Compensation: 0°	Emphasis on discussing measurement error caused by compensation eccentric fixation and on good fixation control
	After training		Fixation control: yes	Reports of patients	Subjective:	< moderate to poor internal validity>
	No follow-up		Head and eye movements: no		report of patients: no changes in visual field
SCT
Pambakian et al (2004)¹⁰	RMD study	31 patients, time after onset: 3 to >12 months, lesion location:	Compensation training	Objective	Objective	Pathology: heterogeneous
	rm 4	Postchiasmatic	Developed home training on a monitor, daily 40 min sessions, length intervention 1 month	Humphrey	Restitution: 0°	Used same instrument for test and training, bias on training effect
	2 before training	Mean age: 49.7 (range 24–75)		Response time, error rates	Compensation:76% improvement	Controlled for age: elderly patients benefited more from training
	2 after training			ADL: response time	ADL: 31 patients 25% improvement	< moderate internal validity >
	Follow-up: 1 month			Subjective
				Standardised questionnaire Kerkhoff	Subjective:
					Improvement of 27 patients
					S (p = <0.0002)
Nelles et al (2001)⁹	RMD stduy	21 patients, mean time after onset:	VRT and compensation training on a board (CVFT), two daily, 30 min sessions, length intervention 1 month	Objective	Objective	Pathology: no description
	rm: 2	1. 5 months (range 0.5–24),		TAP	Restition: not mentioned	Outcome measure and intervention are alike: bias on training effect
	Before training	no description lesion location.		CVFT	Compensation: improvement	Follow-up effect: no outcome measures
	After training	Mean age: 59.2 (±3.5)		Reponse time, error rates	Group A: NS	<poor internal validity >
	follow-up period	Subgroup		Subjective	Group B: S (p⩽0.02)
	8 months from 15 patients	A: eyes fixating B:exploratory eye movements		Standardised questionnaire Kerkhoff with item reading added	Subjective
					Improvement S(p⩽0.05)
Zihl (1995)²	RMD study	14 patients, mean time after onset:	Compensation training	Objective	Objective:	Pathology: homogeneous
	rm 2	11 weeks (range 6–18), lesion location:	Saccadic eye movements with TAP, searching task with slides, 30 min sessions, length intervention 16 (range 8–23).	TAP	Restorative: no	Emphasis study oculomotor scanning
	Before training	Striate cortex, thalamus, occipito-parietal		Visual scanning: Pupil-corneal-reflection method, search time, length of scanpath,number of fixations.	Visual scanning: improvement three variables S (p⩽0.001)	Damage in occipito-parietal cortex, optic radioation, striate cortex more training sessions necessary than occipital lesions
	After training	Mean age: 44 (range 23–74)		Subjective	Subjective: reduction of complaints	No clear subjective measures
	No follow-up			Complaints before and after training		<moderate internal validity >
Kerkhoff et al (1994)¹	RMD study	22 patients, mean time after onset:	Compensation training	Objective:	Objective:	Pathology: homogeneous
	rm: 3	7.5 months (range 1–37), lesion location:	Training in 3 steps:	TAP	Restitution: mean increase	Left vs right hemianopia, early vs late training no significant differences
	Before training	occipital: 12	large saccades on large screen, visual search with slides, transfer to ADL,	Visual search field: TAP, slides, table test	6.6° (range 2° to 24°)	All patients returned to previous job
	After training	Occipito-temporal: 3	5 days a week, 30 min sessions, length intervention 1–3 months	Subjective	visual search field increase: mean 30°	<good internal validity >
	After follow-up	Temporal: 17		Standardised questionnaire Kerkhoff	search time decrease: S (p = 0.01), reduction of errors: 50%
	Follow-up period:	Mean age: 46 (range 16–77)			Subjective
	3 months (1–12)				significant improvements p-value 0.01
Kerkhoff et al (1992)¹¹	RMD study	122 patients,	Compensation training	Objectieve	Objective:	Pathology: heterogeneous
	rm 3	VFD group (n = 92),	Training in 3 steps:	TAP	Restitution: mean increase: 1.6° (range 1.0° to 30°)	More training sessions necessary during training with head movements.
	Before training	VFD+ group (n = 30),	Large saccades on large screen, visual search with slides, transfer to ADL		Visual search field increase: mean 30°	Time after lesion, etiology, type of visual field defect, visual field sparing and age irrelevant for treatment success
	After training	included VFD group,	5 days a week, 30	Subjective	Subjective	<moderate internal validity >
	After follow-up	mean time after onset: 32.8(range 1–220), lesion location	min sessions, length intervention 6 weeks	None	No data
	Follow-up period:	Postchiasmatic.
	Mean 22 months	Mean age 49 (range 117–74)
SCT focused on reading
Kerkhoff et al (1992)¹⁵	RMD study	56 patients, mean time after onset: 40.2 weeks (range 3–220), no description lesion location.	Compensation training	Objective	Restitution mean increase: 1.6° (range 1.0° to 20°)	Pathology: heterogeneous
	rm 3	Mean age: 46.8 (range 13–74)	Computer-based method with moving text, 5 days a week, 40 min sessions, length intervention 14 sessions in 4–6 weeks.	TAP	Reading time reduction:	Most severely disturbed patients benefited most during training
	Before training			Reading time	S (p⩽0.02)	Reduction reading time irrespective initial reading time before training
	After training			Reading errors	Reading errors reduction:	<good internal validity >
	After follow-up			Subjective data	before treatment: 4.97 (8.1)
	Follow-up period			Standardised questionnaire Kerkhoff	after follow-up: 1.48(1.66)
	mean 22 months				Subjective data
	(6 months –5 years)				not reported
Zihl (1995)¹⁶	RMD study	20 patients,	Compensation training	Objective	Restitution: no	Pathology: heterogeneous
	rm: 2	LH group (n = 10)	Computer based with moving text, 5 days a week. 40 min sessions, mean length intervention LH 11 (range 8–16) sessions, RH 22 (range 9–29).	TAP	Reading speed: wpm	Clear relationship between improvements in reading performance and changes of eye movements parameters
	Before training	RH group (n = 10), time after onset:		Pupil-corneal reflection method	LH 76→113	< moderate to good internal validity >
	After training	LH 3–12 weeks (5.8), RH 4–9 weeks(5.9),			RH 53→96
	No follow-up	No description lesion location. Mean age LH group 39 (range 21–53), RH group 37 (range 19–54)		Subjective data	Perceptual span
				None	LH 3.75°→4.03°
					RH 2.79°→3.74°
					Subjective data
					None