Impact of seasonal variation in meteorological conditions on dry eye severity

Figures & data

Figure 1 Dry eye prevalence in US and Miami by months, 2010–2013.

Abbreviation: DE, dry eye.

Table 1 DE symptom questionnaire scores by month from 2014 to 2016, including multiple visits

Month (n)	OSDI (range 0–100) mean ± SD	DEQ5 (range 0–22) mean ± SD	NPSI-E (range 0–100) mean ± SD	Evoked pain to wind (range 0–10) mean ± SD	Evoked pain to light (range 0–10) mean ± SD
January (38)	27.61±20.13	9.61±5.98	14.87±15.94	1.42±2.19	1.39±2.11
February (37)	40.41±26.44	$\mathbf{12}.\mathbf{46}\pm \mathbf{5}.\mathbf{21}$	$\mathbf{29}.\mathbf{73}\pm \mathbf{25}.\mathbf{49}$	3.73±3.83	$\mathbf{4}.\mathbf{35}\pm \mathbf{3}.\mathbf{90}$
March (37)	36.72±29.15	11.22±5.75	21.22±20.90	3.05±3.27	3.95±4.05
April (33)	38.79±22.39	12.36±3.94	27.97±21.04	3.21±3.35	3.82±2.96
May (41)	39.29±23.84	11.83±4.61	22.05±22.77	3.24±3.19	3.37±3.39
June (31)	34.82±27.80	11.19±5.41	18.45±20.96	2.61±3.47	2.68±3.27
July (31)	28.18±26.72	9.94±5.40	13.52±20.00	2.19±3.09	2.19±2.96
August (33)	34.44±22.80	11.91±5.47	24.45±24.65	3.27±3.22	3.45±3.54
September (31)	$\mathbf{47}.\mathbf{62}\pm \mathbf{26}.\mathbf{69}$	12.16±4.97	28.07±25.46	$\mathbf{3}.\mathbf{74}\pm \mathbf{3}.\mathbf{22}$	4.06±3.33
October (29)	39.18±25.28	12.17±4.12	27.28±26.49	3.31±3.41	3.14±3.18
November (22)	38.72±27.26	11.09±5.67	19.95±22.94	3.27±3.48	2.82±3.14
December (34)	35.88±28.26	11.09±5.34	21.21±21.76	2.59±3.12	3.29±3.22
Average of all 12 months (n=397)	36.67±25.74	11.42±5.20	22.39±22.69	2.95±3.26	3.22±3.36
CVa (%)	70.20%	45.53%	101.31%	110.50%	104.19%

Notes:

a CV = coefficient of variance = (average of the SDs of the 12 months/average of the mean of the 12 months)

* 100. Bold, three highest values; Red, maximum value.

Abbreviations: DEQ5, Dry Eye Questionnaire 5; NPSI-E, Neuropathic Pain Symptom Inventory-modified for the eye; OSDI, Ocular Surface Disease Index.

Figure 2 Monthly distribution of the selected DE symptoms and signs among Miami veterans, 2014–2016.

Abbreviations: DE, dry eye; DEQ5, Dry Eye Questionnaire 5; NPSI, Neuropathic Pain Symptom Inventory; OSDI, Ocular Surface Disease Index.

Table 2 DE tear film parameters by month from 2014 to 2016, including multiple visits

Month	Osmolarity (mOsm/L) mean ± SD	TBUT (seconds) mean ± SD	Corneal staining mean ± SD	Schirmer (mm wetting) mean ± SD
January	298.26±14.06	10.17±4.85	1.97±2.02	12.35±9.17
February	302.39±16.44	9.30±4.93	2.14±3.01	14.86±9.12
March	309.44±13.44	10.91±5.66	1.38±1.83	$\mathbf{15}.\mathbf{03}\pm \mathbf{8}.\mathbf{09}$
April	306.03±15.41	9.61±4.51	2.24±2.99	12.87±6.71
May	303.44±12.93	9.38±3.97	$\mathbf{2}.\mathbf{93}\pm \mathbf{2}.\mathbf{91}$	12.30±6.27
June	$\mathbf{310}.\mathbf{68}\pm \mathbf{16}.\mathbf{36}$	10.07±4.85	1.52±2.20	12.84±7.35
July	304.33±15.55	10.84±3.42	1.52±1.82	13.68±8.58
August	<r>310.00±24.94	9.96±5.02	1.70±1.93	12.42±6.73
September	306.30±16.21	10.51±3.61	1.58±2.31	14.45±7.81
October	309.21±15.95	$\mathbf{11}.\mathbf{49}\pm \mathbf{3}.\mathbf{94}$	1.29±1.61	13.97±7.16
November	305.50±13.00	9.21±5.12	2.09±1.90	11.68±5.43
December	310.06±15.73	10.96±6.84	2.29±3.28	12.59±7.25
Average of all 12 months	306.06±16.04	10.19±4.81	1.91±2.43	13.29±7.59
CVa (%)	5.24%	47.19%	127.17%	57.13%

Notes:

a CV = coefficient of variance = (average of the SDs of the 12 months/average of the mean of the 12 months)

* 100. Bold, three highest values; Red, maximum value.

Abbreviations: DE, dry eye; TBUT, tear breakup time.

Table 3 Multivariable linear regression analysis considering the role of season on DE symptoms and signs while considering contribution of demographics and other comorbidities

Selected covariates	DE symptoms				DE signs
	OSDI	DEQ5	NPSI-E	Evoked pain to wind	Osmolarity (mOsm/L)	TBUT (seconds)	Corneal staining	Schirmer (mm wetting)
Cos (month)	3.25*	0.66*	2.96*	0.49**	0.71	−0.14	−0.11	0.36
	−0.17 to 6.67	−0.03 to 1.36	−0.01 to 5.92	0.05 to 0.93	−1.65 to 3.07	−0.85 to 0.57	−0.45 to 0.23	−0.68 to 1.40
Smoking (0 = nonsmoker; 1 = otherwise)	2.63	0.37	0.66	0.02	1.29	0.42	0.05	−1.06*
	−1.03 to 6.30	−0.36 to 1.10	−2.49 to 3.82	−0.45 to 0.48	−1.41 to 4.00	−0.25 to 1.09	−0.25 to 0.35	−2.13 to 0.02
Race (1 = white, 0 = otherwise)	0.44	−0.04	0.66	−0.24	0.43	1.57***	−0.55**	3.17***
	−4.68 to 5.56	−1.17 to 1.10	−3.97 to 5.28	−0.91 to 0.43	−3.09 to 3.95	0.56 to 2.57	−1.06 to −0.03	1.61 to 4.74
Loge (age [year])	8.36	3.33**	3.64	−1.05	0.37	−2.90**	2.97***	−5.95**
	−4.81 to 21.53	0.13 to 6.52	−8.51 to 15.80	−2.95 to 0.85	−9.99 to 10.74	−5.72 to −0.08	1.46 to 4.48	−10.62 to −1.27
Gender (1 = male, 0 = female)	6.13	1.38*	−0.79	0.35	5.66	−1.54**	0.47	0.55
	−2.24 to 14.50	−0.22 to 2.98	−7.38 to 5.81	−0.71 to 1.41	−2.32 to 13.64	−2.98 to −0.09	−0.42 to 1.37	−2.48 to 3.57
Anxiolytics (1 = yes, 0 = no)	10.07***	1.41**	8.68***	1.16***	2.94	0.79	−0.08	−0.74
	4.29 to 15.86	0.17 to 2.65	3.53 to 13.83	0.39 to 1.93	−0.57 to 6.44	−0.38 to 1.97	−0.61 to 0.45	−2.70 to 1.23
Antihistamine (1 = yes, 0 = no)	2.7	0.67	1.1	0.61	0.78	0.04	−0.01	−0.34
	−3.06 to 8.47	−0.55 to 1.88	−3.56 to 5.76	−0.12 to 1.34	−2.80 to 4.37	−1.11 to 1.19	−0.60 to 0.58	−2.07 to 1.40
Antidepressants (1 = yes, 0 = no)	9.98***	1.56***	8.08***	0.66	−1.27	−0.74	0.24	−1.68*
	4.16 to 15.80	0.39 to 2.73	2.84 to 13.33	−0.17 to 1.49	−4.71 to 2.18	−1.90 to 0.43	−0.28 to 0.76	−3.63 to 0.27
Loge (SD patient-specific constant)	2.77***	1.41***	2.79***	0.85***	2.31***	0.68***	0.56***	1.84***
	2.45 to 3.10	1.25 to 1.57	2.57 to 3.00	0.58 to 1.11	1.89 to 2.73	0.25 to 1.11	0.18 to 0.95	1.68 to 2.00
# Visits/unique patients	396/365	397/365	396/365	397/365	376/351	393/365	395/365	393/365

Notes: Non-standardized beta in the first row; robust 95% CIs in the second row;

* P<0.1,

** P<0.05,

*** P<0.01.

Abbreviations: DE, dry eye; DEQ5, Dry Eye Questionnaire 5; NPSI, Neuropathic Pain Symptom Inventory; OSDI, Ocular Surface Disease Index; TBUT, tear breakup time.

Table S1 Monthly DE visit prevalence (%) in the US and Miami, 2010–2013

Month	US	Miami
January	33.6%	20.9%
February	34.2%	19.5%
March	34.5%	20.2%
April	34.6%	$25.9\%$
May	33.0%	25.2%
June	32.9%	22.5%
July	33.5%	22.8%
August	$34.7\%$	22.2%
September	34.6%	22.6%
October	32.7%	22.3%
November	33.0%	21.8%
December	33.5%	24.3%
Average of all 12 months	33.2%	22.5%
Maximum–minimum valuea	2.0	6.4
Coefficient of varianceb	2.2%	8.4%

Notes:

a Difference between highest and lowest frequency for DE visit prevalence.

b Coefficient of variance = SD/mean

* 100. Values for the months with the highest DE visit prevalence are shown in red.

Abbreviation: DE, dry eye.

Table S2 Descriptive statistics of Miami VA Cohort recruited from 2014 to 2016 by season

	Winter N=100	Spring N=99	Summer N=89	Fall N=77	Total N=365
Age, mean (SD; n)	61.8±11.6	62.3±10.2	62.0±10.4	60.7±9.1	61.8±10.4
Demographics, % (n)
White**	48 (48.0)	51 (51.5)	54 (60.7)	29 (37.7)	182 (49.9)
Black**	48 (48.0)	48 (48.5)	35 (39.3)	48 (62.3)	179 (49.0)
Gender, male	92 (92)	94 (94.9)	78 (87.6)	72 (93.5)	336 (92.1)
Ethnicity, Hispanic	25 (25.0)	29 (29.3)	26 (29.2)	20 (26)	100 (27.4)
Smoking status, % (n)
No	15.0 (15)	18 (18.2)	20.2 (18)	9.1 (9)	15.9 (58)
Past	42.0 (42)	52.5 (52)	35.6 (32)	53.3 (41)	45.7 (167)
Current	43.0 (43)	29.3 (29)	43.8 (39)	37.7 (29)	28.4 (140)
Comorbidities, % (n)
Hypertension	72.0 (72)	74.7 (74)	67.4 (60)	70.1 (54)	71.2 (260)
Hypercholesterolemia	60.0 (60)	61.6 (61)	57.3 (51)	63.6 (49)	60.5 (221)
Diabetes	32.0 (32)	28.3 (28)	25.8 (23)	33.8 (26)	29.9 (109)
Osteoarthritis*	44.0 (44)	49.5 (49)	41.6 (37)	62.3 (48)	48.8 (178)
Sleep apnea	22.0 (22)	23.2 (23)	20.2 (18)	19.5 (15)	21.4 (78)
Benign prostatic hypertrophy*	10.0 (10)	3.0 (3)	2.2 (2)	2.6 (2)	4.7 (17)
Medication use, % (n)
Analgesics	60.0 (60)	50.5 (50)	59.1 (52)	64.9 (50)	58.2 (212)
Antidepressants*	38.0 (38)	48.5 (48)	42.7 (38)	58.4 (45)	46.3 (169)
Anxiolytics**	37.0 (37)	47.5 (47)	37.1 (33)	63.6 (49)	45.5 (166)
Antihistamine**	30.0 (30)	11.1 (11)	23.6 (21)	19.5 (15)	21.1 (77)
Gabapentin/pregabalin*	3.0 (3)	2.0 (2)	0.0 (0)	3.9 (3)	2.2 (8)
Mental health, % (n)
Post-traumatic stress disorder	21.0 (21)	23.2 (23)	13.5 (12)	16.9 (13)	18.9 (69)
Depression*	51.0 (51)	61.6 (61)	56.2 (50)	72.4 (55)	59.6 (217)

Notes:

* P≤0.1;

** P≤0.05. Differences in mean age by season examined by ANOVA. Differences in frequencies of all other variables examined by the chi-square test or Fisher’s exact test, as appropriate.