Central Corneal Thickness Among Filipino Patients in an Ambulatory Eye Surgery Center Using Anterior Segment Optical Coherence Tomography

Figures & data

Table 1 Baseline Characteristics of the Study Population (N: 369)

Characteristics	Summary Measures
Age in years	54.09 ± 15.99
Sex of the patient
Male	146 (29.57%)
Female	223 (60.43%)
Degree of affectation
Unilateral	31 (8.40%)
Bilateral	338 (91.60%)
Presence of diabetes
Yes	77 (20.92%)
No	291 (79.08%)
Presence of hypertension
Yes	91 (24.73%)
No	277 (75.27%)

Table 2 Clinical Characteristics of Each Eye Measurement (N: 723)

Characteristics	Summary Measures
Degree of affectation
Left eye	358 (49.52%)
Right eye	365 (50.48%)
Glaucoma medications
No	622 (86.03%)
Yes	101 (13.97%)
Number of medications	0 (0 to 5)
Topical
Beta-blockers	54 (7.47%)
Carbonic anhydrase inhibitors	24 (3.32%)
Prostaglandins	71 (9.82%)
Alpha-adrenergic agonists	41 (5.67%)
Miotics	6 (0.83%)
Oral
Acetazolamide	9 (1.24%)
Central corneal thickness (CCT)	535.59 ± 34.06
Intraocular pressure (IOP)	17.42 ± 5.02
Glaucoma diagnosis
Normal - Glaucoma Suspect (GS)	320 (44.26%)
Ocular Hypertension (OHT)	78 (10.79%)
Open Angle Glaucoma (OAG)	77 (10.65%)
Normal Tension Glaucoma (NTG)	19 (2.63%)
Primary Open Angle Glaucoma (POAG)	58 (8.02%)
Angle Closure Glaucoma (ACG)	239 (33.06%)
Primary Angle Closure Suspect (PACS)	176 (24.34%)
Primary Angle Closure (PAC)	26 (3.60%)
Primary Angle Closure Glaucoma (PACG)	37 (5.12%)
Secondary Glaucoma (SG)	9 (1.24%)

Table 3 Measurements of Each Variable Across Glaucoma Diagnosis

Characteristics	Normal-GS	OAG	ACG	SG	p-val
Number (Percentage)	320 (44.26%)	77 (10.65%)	239 (33.06%)	9 (1.24%)
Age in years	48.93 ± 17.10	57.16 ± 15.14	61.73 ± 10.39	55.22 ± 20.64	<0.01
Sex of the patient
Female	198 (61.88%)	24 (31.17%)	71 (71.55%)	6 (66.67%)	<0.01
Male	122 (38.13%)	53 (68.83%)	68 (28.45%)	3 (33.33%)
Degree of affectation
Unilateral	10 (3.13%)	5 (6.49%)	32 (13.39%)	3 (33.33%)	<0.01
Bilateral	310 (96.88%)	72 (93.51%)	207 (86.61%)	6 (66.67%)
Presence of diabetes	56 (17.50%)	17 (22.08%)	57 (23.85%)	6 (66.67%)	<0.01
Presence of hypertension	48 (15%)	33 (42.86%)	77 (32.22%)	5 (55.56%)	<0.01
Glaucoma medications
No	320 (100%)	35 (45.45%)	201 (84.10%)	3 (33.33%)	<0.01
Yes	–	42 (54.54%)	38 (15.90%)	6 (66.67%)
Topical
Beta-blockers	–	27 (35.06%)	18 (7.53%)	2 (22.22%)	<0.01
CA inhibitors	–	9 (11.69%)	11 (4.60%)	2 (22.22%)	<0.01
Prostaglandins	–	31 (40.26%)	27 (11.30%)	2 (22.22%)	<0.01
Alpha agonists	–	14 (18.18%)	21 (8.79%)	3 (33.33%)	<0.01
Miotics	–	–	6 (2.51%)	–	–
Oral (Acetazolamide)	–	–	7 (2.93%)	2 (22.22%)	<0.01
Central corneal thickness	532.26 ± 34.86	535.87 ± 34.45	531.72 ± 30.13	532.78 ± 35.64	0.81
Median (Range)	533 (430–644)	534 (456–650)	530 (460–610)	526 (500–620)
Intraocular pressure	15.34 ± 2.91	20.62 ± 5.53	17.27 ± 4.87	23 ± 9.08	<0.01
Median (Range)	15 (8–21)	19 (13–48)	16 (10–41)	23 (14–37)

Abbreviations: GS, glaucoma suspect; OAG, open angle glaucoma; ACG, angle closure glaucoma; SG, secondary glaucoma; CA, carbonic anhydrase.

Table 4 Measurements of Each Variable Across Open Angle Glaucoma Subgroups, Ocular Hypertension Group and Normal-Glaucoma Suspect Group

Characteristics	Normal-GS	NTG	POAG	OHT	p-val
Number (Percentage)	320 (44.26%)	19 (4%)	58 (12.21%)	78 (16.42%)
Age in years	48.93 ± 17.10	61.37 ± 14.38	55.78 ± 15.90	47.32 ± 14.46	<0.01
Sex of the patient
Female	198 (61.88%)	10 (52.63%)	14 (24.14%)	39 (50%)	<0.01
Male	122 (38.13%)	9 (47.37%)	44 (75.86%)	39 (50%)
Degree of affectation
Unilateral	10 (3.13%)	1 (5.26%)	4 (6.90%)	4 (5.13%)	0.52
Bilateral	310 (96.88%)	18 (94.74%)	54 (93.10%)	74 (94.87%)
Presence of diabetes	56 (17.50%)	2 (10.53%)	15 (25.86%)	12 (15.38%)	0.31
Presence of hypertension	48 (15%)	8 (42.11%)	25 (43.10%)	11 (14.10%)	<0.01
Glaucoma medications
No	320 (100%)	13 (68.42%)	22 (37.93%)	63 (80.77%)	<0.01
Yes	–	6 (31.58%)	36 (62.07%)	15 (19.23%)
Topical
Beta-blockers	–	4 (21.05%)	23 (39.66%)	7 (8.97%)	<0.01
CA inhibitors	–	2 (10.53%)	7 (12.07%)	2 (2.56%)	<0.01
Prostaglandins	–	4 (21.05%)	27 (46.55%)	11 (14.10%)	<0.01
Alpha agonists	–	2 (10.53%)	12 (20.69%)	3 (3.85%)	<0.01
Central corneal thickness	532.26 ± 34.86	521.58 ± 27.49	540.55 ± 35.41	561.15 ± 31.27	<0.01
Median (Range)	533 (430–644)	515 (468–574)	540 (456–650)	558 (511–643)
Intraocular pressure	15.34 ± 2.91	15.53 ± 1.90	22.29 ± 7.64	22.67 ± 2.54	<0.01
Median (Range)	15 (8–21)	15 (13–20)	20 (13–48)	23 (16–28)

Abbreviations: GS, glaucoma suspect; NTG, normal tension glaucoma; POAG, primary open angle glaucoma; OHT, ocular hypertension; CA, carbonic anhydrase.

Table 5 Measurements of Each Variable Across Angle Closure Glaucoma Subgroups and Normal-Glaucoma Suspect Group

Characteristics	Normal-GS	PACS	PAC	PACG	p-val
Number (Percentage)	320 (44.26%)	176 (31.48%)	26 (4.65%)	37 (6.62%)
Age in years	48.93 ± 17.10	60.40 ± 10.53	64.58 ± 9.84	66.08 ± 8.58	<0.01
Sex of the patient
Female	198 (61.88%)	133 (75.57%)	16 (61.54%)	22 (59.46%)	0.01
Male	122 (38.13%)	43 (24.43%)	10 (38.46%)	15 (40.54%)
Degree of affectation
Unilateral	10 (3.13%)	13 (7.39%)	6 (23.08%)	13 (35.14%)	<0.01
Bilateral	310 (96.88%)	163 (92.61%)	20 (76.92%)	24 (64.86%)
Presence of diabetes	56 (17.50%)	45 (25.27%)	7 (26.92%)	5 (13.51%)	0.10
Presence of hypertension	48 (15%)	55 (31.25%)	12 (46.15%)	10 (27.03%)	<0.01
Glaucoma medications
No	320 (100%)	176 (100%)	19 (73.08%)	6 (16.22%)	<0.01
Yes	–	–	7 (26.92%)	31 (83.78%)
Topical
Beta-blockers	–	–	2 (7.69%)	16 (43.24%)	<0.01
CA inhibitors	–	–	–	11 (29.73%)	–
Prostaglandins	–	–	5 (19.23%)	22 (59.46%)	<0.01
Alpha agonists	–	–	2 (7.69%)	19 (51.35%)	<0.01
Miotics	–	–	1 (3.85%)	5 (13.51%)	<0.01
Oral (Acetazolamide)	–	–	–	7 (18.92%)	–
Central corneal thickness	532.26 ± 34.86	531.27 ± 30.71	542.58 ± 27.96	526.22 ± 27.48	0.27
Median (Range)	533 (430–644)	530 (460–610)	540 (500–604)	530 (469–608)
Intra-ocular pressure	15.34 ± 2.91	15.73 ± 2.67	20.35 ± 5.26	22.41 ± 7.59	<0.01
Median (Range)	15 (8–21)	16 (10–24)	20 (12–32)	22 (11–41)

Abbreviations: GS, glaucoma suspect; PACS, primary angle closure suspect; PAC, primary angle closure; PACG, primary angle closure glaucoma; CA, carbonic anhydrase.

Table 6 Correlation Between Intraocular Pressure and Central Corneal Thickness Among Glaucoma Diagnosis

Estimates	Overall	Normal-GS	OAG	ACG	SG
Correlation coefficient (ρ)	0.195	0.158	0.103	0.124	0.299
95% CI	0.12 to 0.26	0.05 to 0.26	−0.06 to 0.26	−0.03 to 0.25	−0.46 to 0.80
p-value	<0.01	0.01	0.20	0.16	0.44

Abbreviations: GS, glaucoma suspect; OAG, open angle glaucoma; ACG, angle closure glaucoma; SG, secondary glaucoma.

Table 7 Correlation Between Intraocular Pressure and Central Corneal Thickness Among Open Angle Glaucoma Subgroups, Ocular Hypertension Group and Normal-Glaucoma Suspect Group

Estimates	Normal-GS	NTG	POAG	OHT
Correlation coefficient (ρ)	0.158	0.407	−0.026	−0.119
95% CI	0.05 to 0.26	−0.06 to 0.73	−0.28 to 0.23	−0.33 to 0.11
p-value	0.01	0.08	0.85	0.30

Abbreviations: GS, glaucoma suspect; NTG, normal tension glaucoma; POAG, primary open angle glaucoma; OHT, ocular hypertension.

Table 8 Correlation Between Intraocular Pressure and Central Corneal Thickness Among Angle Closure Glaucoma Subgroups and Normal-Glaucoma Suspect Group

Estimates	Normal-GS	PACS	PAC	PACG
Correlation coefficient (ρ)	0.158	−0.114	0.555	0.530
95% CI	0.05 to 0.26	−0.26 to 0.04	0.21 to 0.78	0.25 to 0.73
p-value	0.01	0.13	0.01	<0.01

Abbreviations: GS, glaucoma suspect; PACS, primary angle closure suspect; PAC, primary angle closure; PACG, primary angle closure glaucoma.

Table 9 Linear Regression Models for the Different Glaucoma Diagnoses

Predictors	Univariable		Multivariable
	β (95% CI)	p-value	β (95% CI)	p-value
Age in years	−0.36 (−0.21 to −0.52)	<0.01	−0.37 (−0.20 to −0.55)	<0.01
Sex of the patient
Female	Reference		Reference
Male	2.76 (−2.33 to 7.85)	0.29	1.34 (−3.80 to 6.49)	0.61
Use of glaucoma medications
Beta-blockers	2.21 (−7.26 to 11.67)	0.65	−0.09 (−12.16 to 11.98)	0.99
Carbonic anhydrase inhibitors	−6.13 (−20.01 to 7.76)	0.39	−6.01 (−22.86 to 10.84)	0.48
Prostaglandins	−3.00 (−11.36 to 5.36)	0.48	−7.58 (−18.10 to 2.94)	0.16
Alpha agonists	4.39 (−6.36 to 15.15)	0.42	11.79 (−2.44 to 26.02)	0.19
Miotics	−4.96 (−32.39 to 22.47)	0.72	−4.34 (−34.66 to 25.97)	0.78
Acetazolamide	1.20 (−21.24 to 23.65)	0.92	7.60 (−17.85 to 33.05)	0.56
Presence of diabetes	1.92 (−4.25 to 8.08)	0.54	8.97 (2.37 to 15.58)	0.01
Presence of hypertension	−5.11 (−10.91 to 0.70)	0.09	−2.88 (−9.32 to 3.57)	0.38
Intraocular pressure (mm Hg)	1.32 (0.84 to 1.81)	<0.01	0.71 (0.14 to 1.29)	0.02
Diagnosis
Normal Glaucoma Suspect	Reference		Reference
Ocular Hypertension	28.89 (20.75 to 37.04)	<0.01	24.16 (14.99 to 33.32)	<0.01
Normal Tension Glaucoma	−10.68 (−25.91 to 4.55)	0.17	−3.92 (−19.40 to 11.55)	0.62
Primary Open Angle Glaucoma	8.29 (−0.91 to 17.50)	0.08	7.25 (−4.62 to 19.11)	0.23
Primary Angle Closure Suspect	−0.99 (−7.03 to 5.06)	0.75	2.94 (−3.38 to 9.26)	0.36
Primary Angle Closure	10.32 (−2.82 to 23.46)	0.12	13.32 (−0.49 to 27.13)	0.10
Primary Angle Closure Glaucoma	−6.04 (−17.23 to 5.14)	0.85	−4.68 (−19.91 to 10.56)	0.55
Secondary Glaucoma	0.52 (−21.29 to 22.32)	0.96	−8.29 (−31.47 to 14.90)	0.48

Table 10 Comparison of IOP and CCT Values with Previous Studies

Measurements	Badr (2019)^Citation14		Soriano (2007)^Citation27	Sosuan (2021)	p-value
Intraocular Pressure	16.61 ± 3.50		–	17.42 ± 5.02	0.14
Ocular Hypertension	–		23 ± 4	22.67 ± 2.54	0.77
Normal Tension Glaucoma	–		13 ± 4	15.53 ± 1.90	0.01
Primary Open Angle Glaucoma	–		23 ± 7	22.29 ± 7.64	0.70
Primary Angle Closure Glaucoma	–		28 ± 15	22.41 ± 7.59	0.20
Central Corneal Thickness	535.44 ± 39.70		–	535.59 ± 34.06	0.97
Normal-Glaucoma Suspect	534.10 ± 37.40		–	532.26 ± 34.86	0.72
Ocular Hypertension	503.62 ± 44.50		588 ± 28	561.15 ± 31.27	<0.01
Normal Tension Glaucoma	525.50 ± 6.40		526 ± 40	521.58 ± 27.49	0.92
Primary Open Angle Glaucoma	548 ± 56.70		538 ± 33	540.55 ± 35.41	0.01
Primary Angle Closure Glaucoma	535.71 ± 43.80		531 ± 32	526.22 ± 27.48	0.63
Secondary Glaucoma	539.27 ± 25		–	532.78 ± 35.64	0.62

Badr M, Masis Solano M, Amoozgar B, Nguyen A, Porco T, Lin S. Central corneal thickness variances among different asian ethnicities in glaucoma and nonglaucoma patients. J Glaucoma. 2019;28(3):223–230. doi:10.1097/ijg.0000000000001180

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