prevalence of corneal astigmatism in cataract surgery candidates in bangkok, thailand kaevalin...
DESCRIPTION
Methods Prospective study Institutional Review Board approved January 2007-October 2009 Cataract surgery candidates Inclusion criteria Presence of cataract Age ≥ 40 years old Exclusion criteria Corneal disease Irregular astigmatism Presence of pterygium Previous ocular surgery Uncooperative patientTRANSCRIPT
Prevalence of corneal astigmatism in cataract surgery candidates
in Bangkok, Thailand
Kaevalin Lekhanont, MD, Wadakarn Wuthisiri, MD, Porntip Chatchaipun, BSc, Anun Vongthongsri, MD
Ramathibodi Hospital, Mahidol University
The authors have no proprietary interest in any product or instrument used in this study
Purpose To evaluate the prevalence and characteristics
of corneal astigmatism in senile cataract patients scheduled for cataract surgery
Methods Prospective study Institutional Review
Board approved January 2007-October
2009 Cataract surgery
candidates Inclusion criteria
Presence of cataract Age ≥ 40 years old
Exclusion criteria Corneal disease Irregular astigmatism Presence of pterygium Previous ocular
surgery Uncooperative patient
Methods Presurgical screening
examinations Keratometry (Topcon-
KR8100) Manifest refraction Best-corrected visual
acuity Slit-lamp examination Applanation tonometry Dilated fundus
examination
Statistical analyses STATA version 11 Mean, SD or median and
range Describing continuous
data Frequency and
percentage Describing categorized
data The level of significance
at P < 0.05
Results 2010 eyes in 1005 patients
Characteristic Value
Mean age (SD) (y) 68.21 (9.19)
Range of age (y) 42-96Gender (male/female) 388/ 617
Median value of corneal astigmatism (D) 0.88 (0-4.5)
Mean keratometry (D) - Steepest meridian - Flattest meridian
44.91 ± 1.5444.02 ± 1.56
Range of keratometry (D) 38-49
Prevalence of corneal astigmatism
Corneal Astigmatism (D)
Prevalence (%) 95%CI
≤0.5 20.97 17.31-25.01
>0.5-1 43.49 38.87-48.19>1-2 28.92 24.78-33.33
>2-3 5.30 3.42-7.78
>3 1.32 0.49-2.86
35.5% of the eyes had corneal astigmatism ≥ 1.25D
Corneal astigmatism in the age groups
Corneal cylinder in 4 age groups
0
10
20
30
40
50
<60 61-70 71-80 >80
Age group (years)
Freq
uenc
y (%
) ≤0.5 D
>0.5-1 D
>1-2 D
>2-3 D
>3 D
Corneal astigmatism increased with age (P <0.01)
Axis distribution
Axis distribution
ATR 62%
Oblique12%
WTR 26%
WTR
ATR
Oblique
[22.06-30.34][8.88-15.02]
[57.61-66.73]
Astigmatic axes in the age groups
Axis of astigmatism in 4 age groups
0102030405060708090
<60 61-70 71-80 >80
Age group (years)
Freq
uenc
y (%
)
WTR
ATR
Oblique
ATR astigmatism increased with age (P <0.001)
Discussion Attempted to determine the prevalence of
different amounts of corneal astigmatism A few such reports are available in the literature Prevalence of corneal astigmatism increased with
age, particularly ATR direction, similar to previous studies
Provide a useful information for cataract surgeon Several options for correcting corneal astigmatism
at the time of cataract surgery may be considered
Studies Ferrer-Blasco et al, 2009
Riley et al, 2001
Gonzalez et al, 2007
Present study, 2009
Eyes/ patients 4540/2415 502/488 N/A 2010/1005
Age 60.59±9.87 74.9±9.8 N/A 68.21±9.19
Sex 68.2% F 62% F N/A 61.37% F
Corneal astigmatism ≥ 1 D
34.8% N/A 63% 37.8%
Mean corneal astigmatism
0.90±0.93 0.9±0.80.75 (median)
N/A 1.05±0.620.88 (median)
Range of astigmatism
0.0-6.75 0.0-6.50 N/A 0.0-4.50
Axis of astigmatism N/A 50% ATR N/A 62% ATR
Mean steepest K (D) 44.08±1.61 44.1±1.7 N/A 44.91 ± 1.54
Range of K (D) 38-48 38.6-50.5 N/A 38-49
Conclusions The prevalence of corneal astigmatism > 1 D
was 35.5% in this study population Emphasize the importance of considering
preexisting corneal astigmatism in senile cataract patients prior to surgery to achieve the optimal postoperative refractive outcomes
Thank you for your attention