INCIDENCE OF HERPES SIMPLEX VIRUS KERATITIS AND OTHER OCULAR DISEASE: GLOBAL REVIEW AND ESTIMATES

Figures & data

Table 1. Number of available estimates from the 7 studies meeting quality criteria, and pooling decision.

HSV clinical entity	All cases	New cases	Recurrent cases	Pooling and estimation of global burden done?
Any ocular disease	2	3	2	No; disease definition not specific
Any keratitis	2^a	3	2	Yes; for all categories
Epithelial keratitis	3	2	1	Yes for all and new cases, no for recurrent cases due to only one available estimate
Stromal keratitis	2	2	1	Yes for all and new cases, no for recurrent cases due to only one available estimate
Endothelial keratitis	0	0	0	No; no available estimates
Uveitis	1	2	1	Yes for new cases, no for all and recurrent cases due to only one available estimate
Retinitis	0	3	0	Yes for new cases, no for all and recurrent cases due to no available estimates
Blepharo-conjunctivitis	1	2	1	Yes for new cases, no for all and recurrent cases due to only one available estimate

^aAdditional estimate based on highly probable (only) cases also available but not included in tally.

Figure 1. Flow diagram of HSV ocular disease literature search with number of studies at each stage of the process.

Table 2. Pooled incidence and estimated global burden among 1 month-99 year olds in 2016 for selected clinical entities.

HSV clinical entity	Pooled incidence (95%CI) (cases per 100,000 person-years)	No. of contributing studies	I^2	Cochrane’s Q test	Estimated no. of global cases among 1 month-99 year olds in 2016 in millions (95%CI)
Any keratitis	24.0 (14.0–41.0)	2^28, 36	97.7%	p < .001	1.7 (1.0–3.0)
Any new keratitis	9.2 (6.4–13.2)	3^28, 32, 36	93.6%	p < .001	0.7 (0.5–1.0)
Any recurrent keratitis	14.8 (9.8–22.4)	2^28, 36	93.8%	p < .001	1.1 (0.7–1.6)
All epithelial keratitis	16.1 (11.6–22.3)	3^28, 30, 36	92.6%	p < .001	1.2 (0.8–1.6)
New epithelial keratitis	6.4 (5.2–7.9)	2^28, 32	65.3%	p = .090	0.5 (0.4–0.6)
All stromal keratitis	4.9 (1.4–17.0)	2^28, 36	97.5%	p < .001	0.4 (0.1–1.2)
New stromal keratitis	1.1 (0.4–3.5)	2^28, 32	88.1%	p = .004	0.1 (0.0–0.3)
New uveitis	0.2 (0.0–1.1)	2^28, 32	80.6%	p = .023	0.0 (0.0–0.1)
New retinitis	0.01 (0.01–0.02)	3^15, 16, 32	0.0%	p = .949	0.00 (0.00–0.00)
New blepharo-conjunctivitis	3.2 (1.8–5.5)	2^28, 32	91.1%	p = .001	0.2 (0.1–0.4)

Values do not necessarily sum across rows due to different studies contributing estimates, and potential contribution of endothelial keratitis to estimates for any keratitis. I² is the percentage of the variation between the estimates explained by between-study variation (i.e., it is a measure of the heterogeneity between studies). Cochrane’s Q test assesses whether the estimates are significantly different between studies. All values shown to 1 d.p., except for pooled incidence estimates and estimated number of global cases for new retinitis which are shown to 2 d.p.