Table
A Risk factors for cataractw1
Table B Variation in predicted power
(in dioptres) of intraocular lens with different lens formulas ...
Table C Postoperative complications
of cataract surgeryw9
Web references
Table A Risk factors for
cataractw1
| Risk |
Odds ratio
|
| Age |
1.40w2
|
| Sex—women:men, 1.22:1 |
3.03w3
|
| Diabetes mellitus |
2.72w3
|
| Sunlight |
1.10w4
|
| Toxicity to drugs, including steroids,
chlorpromazine, bulsulphan, amiodarone, gold |
3.25 (steroids)w3
|
| Nutrition and socioeconomic status |
1.47-1.90w5
|
| Lifestyle: |
|
| Smoking |
2.35-3.75w3
|
| Alcohol |
1.34-1.57w6
|
| Ocular disease—uveitis, glaucoma,
high myopia |
1.99 (myopia)w2
|
| Ocular trauma |
2.4w7
|
| Dehydration or diarrhoeal crisis |
3.1w8
|
Table B Variation in predicted
power (in dioptres) of intraocular lens with different lens formulas (assuming
an A constant of 118 and mean K reading of 42.5D)
| Axial length (mm) |
SRK-T formula
|
Hoffer-Q formula
|
Holladay-II formula
|
SRK-II formula
|
| 18 |
41.6
|
45.6
|
43.3
|
37.8
|
| 20 |
32.9
|
34.6
|
33.9
|
31.8
|
| 22 |
25.8
|
26.6
|
26.3
|
24.8
|
| 26 |
13.9
|
13.8
|
13.8
|
14.3
|
| 32 |
- 0.3
|
- 1.2
|
- 0.7
|
- 0.7
|
A 2 dioptre difference represents about three lines on
a Snellen visual acuity chart.
Table C Postoperative complications
of cataract surgeryw9
| Early (within 48 hours) |
Signs and symptoms |
Frequency (%)
|
| Corneal oedema* |
Cloudy vision |
9.5
|
| Raised intraocular pressure* |
Pain, ±
nausea and vomiting |
7.9
|
| Uveitis (more than expected) |
Pain, redness |
5.6
|
| Wound leak or rupture |
Watering eye, reduced vision |
1.2
|
| External eye infection |
Redness, discharge |
0.06
|
| Internal eye infection (endophthalmitis)† |
Severe pain, reduced vision |
0.03
|
| Retinal detachment† |
Flashes, floaters, ±
reduced vision |
0.03
|
| Retinal tear |
Flashes, floaters |
0.02
|
| Late (48 hours to 3-4 months) |
Signs and symptoms |
Frequency (%)
|
| Endophthalmitis† |
Severe pain, reduced vision |
0.1
|
| Retinal detachment and tear† |
Flashes, floaters, ±
reduced vision |
0.14
|
*Generally short lived and self-limiting.
†Likely to cause permanent visual loss.
Web references
-
Dolin P. Epidemiology of cataract. In: Johnson GJ, Minassian DC, Weale
R, eds. The epidemiology of eye disease. London: Chapman and Hall
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-
Klein BE, Klein R, Moss SE. Incident cataract surgery: the Beaver Dam study.
Ophthalmology 1997;104:573-80.
-
Delcourt C, Cristol JP, Tessier F, Leger CL, Michel F, Papoz L. Risk factors
for cortical, nuclear and posterior subcapsular cataract: the POLA study.
Am J Epidemiology 2000;151:497-504.
-
West SK, Duncan DD, Munoz B, Rubin GS, Fried LP, Bandeen-Roche K, et al.
Sunlight exposure and risk of lens opacity in a population based study:
the Salisbury eye evaluation project. JAMA 1998;289:714-8.
-
Leske MC, Wu SY, Connell AM, Hyman L, Schachat AP. Lens opacities, demographic
factors and nutritional supplements in the Barbados eye study. Int J
Epidemiology 1997;26:1314-22.
-
Ritter LL, Klein BE, Klein R, Mares-Perlman JA. Alcohol use and lens opacities
in the Beaver Dam eye study. Arch Ophthalmol 1993;111:113-7.
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Wong TY, Klein BE, Klein R, Tomany SC. Relation of ocular trauma to cortical,
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Br J Ophthalmol 2002;86:152-5.
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Zodpey SP, Ughade SN, Khanolkar VA, Shrikhande SN. Dehydrational crisis
from severe diarrhoea and risk of age-related cataract. J Indian Med
Assoc 1999;97:13-5.
-
Desai P, Misassian DC, Reidy A. The national cataract survey 1997/98: a
report of the results of the clinical outcomes. Br J Ophthalmol
1999;83:1336-40.