Evaluation of Corneal Epithelial Thickness and Dry Eye Disease Tests in Thalassemic Adolescents

Figures & data

Table 1 Demographic and Laboratory Characteristics of Thalassemic Patients

		Thalassemic Patients n=120
Age (years)	Mean±SD	17.54±2.23
	Min-max	14.00–23.00
Duration of thalassemia (years)	Mean±SD	16.09±1.44
	Min-max	14.00–22.00
Serum ferritin level (ng/mL)	Mean±SD	1328.37±433.02
	Min-max	456.00–2000.00
Pre-transfusion haemoglobin level [gm/dl]	Mean±SD	7.50±0.50
	Min-max	6.80–8.50
Liver iron concentration (mg iron/gm dry weight of liver.)	Mean±SD	4.99±2.91
	Min-max	1.50–12.00
	Number (Percentages) of hepatic iron overload severity grades	22 (18.3%); normal 89 (74.2%); mild to moderate 9 (7.5%); severe

Table 2 Comparison Between Thalassemics and Controls Regarding Various Clinical Parameters

		Thalassemia	Control	Independent Sample t-test
				t	P value
Age (years)	Mean±SD	17.54±2.23	16.78±1.28	3.22	0.001
Gender	Female	54 (45%)	58 (48.3%)	0.076*	0.783
	Male	66 (55%)	62 (51.7%)
BCVA	Mean ±SD	0.09 ±- 0.1	0.08 ± 0.09	1.888	0.157
(logMAR)	(range of Snellen acuity ratios)	(20/20-20/30)	(20/20-20/25)
TBUT (sec)	Mean±SD	6.13±1.52	12.34±1.82	−28.69	0.000
Schirmer test (mm/5min)	Mean±SD	12.62±3.20	12.71±2.24	−0.26	0.797
OSDI	Mean±SD	22.38±16.00	11.07±7.27	238.00	0.000
Fluorescein staining	Mean±SD	1.09±1.20	0.15±0.34	140.24	0.000
Lissamine staining	Mean±SD	1.00±1.15	0.13±0.34	139.70	0.000
Superior CET	Mean±SD	46.52±3.11	50.80±3.90	226.67	0.000
Inferior CET	Mean±SD	48.05±3.50	53.58±2.36	208.82	0.000
MSD	Mean±SD	2.85±0.61	1.76±0.47	222.92	0.000

Notes: *Chi-square test. P values were considered significant if <0.05.‎ Significant P values are bold.

Abbreviations: OSDI, ocular surface disease index questionnaire; score range values: 0–12 (no disability) 13–22 (mild dry eye), to 23–32 (moderate dry eye), and 33–100 (severe dry eye); TBUT, tear breakup time; CET, corneal epithelial thickness; MSD, map standard deviation.

Table 3 Correlations Between Corneal Epithelial Thickness (CET), Map, Standard Deviation (MSD), OSDI Scores and Various Clinical Parameters in Thalassemia Group

		Superior CET	Inferior CET	MSD	OSDI Score
Age	r	−0.013	−0.049	0.037	−0.073
	P	0.889	0.594	0.689	0.430
Duration of disease	r	−0.090	0.068	0.125	−0.166
	P	0.328	0.460	0.173	0.069
TBUT	r	0.479	0.345	−0.453	−0.054
	P	0.000	0.000	0.000	0.559
Fluorescein staining	r	−0.538	−0.435	0.524	0.079
	P	0.000	0.000	0.000	0.390
Lissamine staining	r	−0.554	−0.421	0.537	0.066
	P	0.000	0.000	0.000	0.471
Schirmer test	r	−0.036	−0.092	0.005	0.016
	P	0.698	0.320	0.956	0.866
OSDI score	r	0.041	0.074	−0.066	1.000
	P	0.653	0.422	0.473
Superior CET	r	1.000	0.677	−0.852	0.041
	P		0.000	0.000	0.653
Inferior CET	r	0.677	1.000	−0.573	0.074
	P	0.000		0.000	0.422
MSD	r	−0.852	−0.573	1.000	−0.066
	P	0.000	0.000		0.473

Notes: P values were considered significant if <0.05.‎ Significant P values are bold.

Abbreviations: TBUT, tear breakup time; OSDI, ocular surface disease index questionnaire; MSD, map standard deviation.

Table 4 Correlations Between Serum Ferritin Level, Liver Iron Concentration, Corneal Epithelial Thickness Parameters and Various Clinical Tests in Thalassemia Group

		Serum Ferritin Level	Liver Iron Concentration
Age	r	0.042	0.070
	P	0.652	0.450
Duration of disease	r	0.102	0.041
	P	0.267	0.658
TBUT	r	−0.392	−0.319
	P	0.000	0.000
Fluorescein staining	r	0.520	0.539
	P	0.000	0.000
Lissamine staining	r	0.505	0.462
	P	0.000	0.000
Schirmer test	r	0.093	0.159
	P	0.314	0.082
OSDI score	r	0.244	0.333
	P	0.007	0.000
Superior CET	r	−0.610	−0.472
	P	0.000	0.000
Inferior CET	r	−0.393	−0.340
	P	0.000	0.000
MSD	r	0.668	0.518
	P	0.000	0.000

Notes: P values were considered significant if <0.05. Significant P values are bold.

Abbreviations: TBUT, tear breakup time; OSDI, ocular surface disease index questionnaire; CET, corneal epithelial thickness; MSD, map standard deviation.