106 Jeganathan et al.
Cataract extraction in high myopia must be considered carefully because patients with high myopia are at increased risk of retinal breaks and retinal detachment.51,52
Glaucoma
An association between high myopia and primary open angle glaucoma (POAG) has been supported by numerous case series, case control, and large population-based studies (Table 2).38,53–61,63 The prevalence of myopia with POAG is 4% and may increase to 6–7% with higher degrees of myopia.62 In the BMES, after adjusting for age, gender and other risk factors, glaucoma was two to three times as frequent as eyes with myopia compared with eyes with emmetropia or hyperopia.55 In the Barbados Eye Study, a myopic refraction was one of several risk factors in adult black people with prevalent POAG.38,63 Both the BMES and Barbados Eye Study confirm a dose-response between the level of myopia and prevalence of glaucoma.38,55,63 Severe myopia (< − 4D), not mild myopia, has been shown to be a significant risk factor for subsequent visual field loss in patients with POAG.64 However, in the Ocular Hypertension Treatment Study, high myopia was not predictive of POAG.65 Moreover, individuals with myopia were not found to have a higher incidence or progression of glaucoma in the Ocular Hypertension Treatment Study or Early Manifest Glaucoma Trial.65,66 High myopia is related with higher intraocular pressure (IOP) and occurs more often in glaucoma patients than in the normal population, particularly amongst the elderly.55 In POAG patients with high IOP, higher myopia is thought to be a factor that threatens their quality of life.67 Interestingly, the visual field of myopic eyes more often improves and less often worsens once the IOP has been lowered therapeutically. There is now evidence that myopia is a risk factor for the development of ocular hypertension, based on data of the screening examination for the Early Manifest Glaucoma Trial and other studies.68–70 Structural changes associated with myopia, such as longer axial length, larger and/or tilted optic disc, thinner lamina cribrosa, peripapillary atrophy, and shared alteration in collagen and other extracellular matrix of the optic nerve is postulated to make the upper maculopapillary bundle (lower cecofield) more susceptible to glaucomatous injury.67 Highly myopic patients are also at higher risk of postoperative hypotony maculopathy.71
Table 2. Summary of Published Data on Myopia and Glaucoma
|
|
|
Study |
Sample |
Age |
|
Definition of |
Summary of Main |
Source |
Year |
Place |
Design |
Size (n) |
(Years) |
Methodology |
Myopia |
Findings |
|
|
|
|
|
|
|
|
|
Daubs and |
1981 |
London, |
CCS |
953 |
≥ 40 |
SR OAG-eyes |
High myopia |
OR of OAG = 3.1 (95% CI 1.6, |
Crick53 |
|
United |
|
|
|
with open |
(≤ −5 D) |
5.8) OR of OAG = 1.3 |
|
|
Kingdom |
|
|
|
angles and |
Low myopia |
(1.0, 1.8). Adjusted for age, |
|
|
|
|
|
|
VFD |
(−0.25 D to |
IOP, sex, family history, blood |
|
|
|
|
|
|
|
−5 D) |
pressure, astigmatism, season, |
|
|
|
|
|
|
|
|
health. |
Ponte et al.; |
1994 |
Italy |
PBCS |
264 |
≥ 40 |
Cases: IOP ≥ 24, |
≤ −0.5 D |
OR of glaucoma prevalence = |
Casteldaccia |
|
|
|
|
|
history of |
|
5.56 (1.85, 16.67). Adjusted for |
Eye Study54 |
|
|
|
|
|
glaucoma, |
|
diabetes, hypertension, |
|
|
|
|
|
|
VFD. Controls: |
|
steroids, iris texture. |
|
|
|
|
|
|
IOP ≤20, |
|
|
|
|
|
|
|
|
CDR 0–0.2 |
|
|
Mitchell et al; |
1999 |
Sydney, |
PBCS |
3654 |
≥ 49 |
AR and SR OAG |
High myopia |
OR of OAG prevalence = |
Blue |
|
Australia |
|
|
|
defined as |
≤ −3 D |
3.3 (1.7, 6.4) OR of OAG |
Mountains |
|
|
|
|
|
CDR ≥0.7 or |
Low myopia |
prevalence = 2.3 (1.3, 4.1). |
Eye Study55 |
|
|
|
|
|
CD asymmetry |
(−3 D to |
Adjusted for gender, family |
|
|
|
|
|
|
≥0.3 |
≥ −1 D) |
history, diabetes, hypertension, |
|
|
|
|
|
|
|
|
migraine, steroid use, |
|
|
|
|
|
|
|
|
psedoexfoliation. |
Wu et al; |
1999 |
Barbados |
PBSC |
4709 |
40–84 |
AR OAG-eyes |
≤ −0.5 D |
OR of OAG prevalence = |
Barbados |
|
|
|
|
|
with open |
|
1.48 (1.12,1.95). |
Eye Study38 |
|
|
|
|
|
angles and VFD |
|
|
(Continued )
Myopia Pathological of Morbidity Ocular 107
|
|
|
|
|
Table 2. |
(Continued ) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Study |
Sample |
Age |
|
Definition of |
Summary of Main |
Source |
Year |
Place |
Design |
Size (n) |
(Years) |
Methodology |
Myopia |
Findings |
Grodum et al.56 |
2001 |
Malmo, |
PBCS |
32,918 |
57–79 AR OAG defined |
≤ −1 D |
|
|
Sweden |
|
|
as 2 repeatable |
|
|
|
|
|
|
VFD |
|
Yoshida et al.57 |
2001 |
Yokohama, |
CCS |
64,394 |
≥ 49 AR POAG defined |
≤ −3 D |
|
|
Japan |
|
|
as glaucomatous |
|
|
|
|
|
|
VFD associated |
|
|
|
|
|
|
with abnormal |
|
|
|
|
|
|
optic disc |
|
|
|
|
|
|
and/or disc |
|
|
|
|
|
|
margin |
|
Prevalence of newly diagnosed OAG increased with increasing myopia (p < 0.01), and 1.5% in moderate to high myopia. Adjusted for age, gender, IOP.
Prevalence of POAG is higher in moderate to high myopes
(p < 0.001).
Wong et al; |
2003 Wisconsin, PBCS |
4670 43–86 AR and SR POAG ≤ −1 D |
OR of prevalent POAG for |
Beaver Dam |
USA |
defined as |
myopia = 1.6 (1.1, 2.3). |
Eye Study58 |
|
IOP ≥ 22, |
Adjusted for age and gender. |
|
|
CDR ≥ 0.8, VFD, |
|
|
|
history of |
|
|
|
glaucoma |
|
|
|
treatment |
|
|
|
|
|
|
|
|
(Continued ) |
.al et Jeganathan 108
Table 2. (Continued )
|
|
|
Study |
Sample |
Age |
|
Definition of |
Summary of Main |
Source |
Year |
Place |
Design |
Size (n) |
(Years) |
Methodology |
Myopia |
Findings |
|
|
|
|
|
|
|
|
|
Suzuki et al; |
2006 |
Tajimi, |
PBCS |
119 |
≥ 40 |
AR POAG |
Low myopia |
OR of prevalent POAG = |
Tajimi |
|
Japan |
|
|
|
diagnosed from |
(−3 D to −1 D) |
1.85 (1.03, 3.31) for low |
Eye Study59 |
|
|
|
|
|
IOP, CDR, |
Moderate to |
myopia and 2.60 (1.56, 4.35) |
|
|
|
|
|
|
and VFD |
high myopia |
for moderate to high myopia. |
|
|
|
|
|
|
|
(≤ −3 D) |
Adjusted for age, gender, IOP, |
|
|
|
|
|
|
|
|
corneal curvature, central |
|
|
|
|
|
|
|
|
corneal thickness, diabetes, |
|
|
|
|
|
|
|
|
migraine, hypertension, |
|
|
|
|
|
|
|
|
smoking, family history of |
|
|
|
|
|
|
|
|
glaucoma. |
Xu. et al; |
2007 |
Beijing, |
PBCS |
4439 |
≥ 40 AR and SR |
High myopia |
OR of prevalent POAG in highly |
|
Beijing |
|
China |
|
|
|
POAG diagnosed |
(> −8 D) |
myopic marked myopia = |
Eye Study60 |
|
|
|
|
|
from CDR |
Marked myopia |
2.28 (0.99, 5.25) compared to |
|
|
|
|
|
|
(photos) and |
(< −6 D to −8 D) |
moderate myopia. The OR was |
|
|
|
|
|
|
IOP |
Moderate myopia |
significantly higher than in |
|
|
|
|
|
|
|
(< −3 D to −6 D) |
the group with low myopia |
|
|
|
|
|
|
|
|
(OR 3.5; 1.71, 7.25). |
Casson, et al; |
2007 |
Meiktila, |
PBCS |
2076 |
≥ 40 |
AR POAG |
Myopia < 0.5 D |
Myopia (P = 0.049), increasing |
Meiktila |
|
Burma |
|
|
|
diagnosed from |
|
age, and IOP (P < 0.001) were |
Eye Study61 |
|
|
|
|
|
IOP, CDR, and |
|
significant risk factors for |
|
|
|
|
|
|
VFD |
|
POAG. |
Myopia Pathological of Morbidity Ocular 109
AR: autorefraction, CDR: cup-disc ratio, CI: confidence interval, CCS: case control study, D: dioptres, IOP: intraocular pressure, OR: odds ratio, PBSC: pop- ulation-based cross-sectional study, POAG: primary open angle glaucoma, SR: subjective refraction, VFD: visual field defect.