Diabetes and Hypertension as Risk Factors for Posterior Subcapsular Cataract
Yes, both diabetes mellitus and systemic hypertension significantly increase the risk of posterior subcapsular (PSC) cataracts, with the combined presence of both conditions conferring an even greater risk than either condition alone.
Risk Magnitude
Diabetes mellitus increases PSC cataract risk with an odds ratio of 1.79, while hypertension increases risk with an odds ratio of 1.49, but when both conditions coexist, the combined risk escalates to an odds ratio of 2.66 1.
- Hypertension is the most prominent single risk factor among cataract patients, present in 43.8% of patients with subcapsular cataracts specifically 2.
- Diabetes mellitus shows a well-established association with PSC cataracts across multiple studies 3, 4, 1.
- The combination of hypertension and diabetes creates a synergistic effect, more than doubling the baseline risk for cataract extraction 1.
Evidence Quality and Consistency
The evidence demonstrates remarkable consistency across multiple case-control studies:
- A 1992 Veterans Administration study found that systemic hypertension significantly increased PSC cataract risk, with diabetes also showing strong association 3.
- However, one 1989 Maryland-based case-control study (n=168 matched pairs) found that hypertension was NOT a risk factor for PSC cataracts, while diabetes was reconfirmed as a risk factor 4. This represents contradictory evidence on hypertension specifically.
- The most comprehensive analysis from 1989 (n=161 cases, 196 controls) demonstrated clear dose-response relationships and combined effects 1.
- The most recent 2019 study (n=812 patients) reinforces hypertension as the predominant risk factor in modern cataract populations 2.
Despite one contradictory study, the preponderance of evidence—including the largest and most recent investigation—supports both diabetes and hypertension as independent PSC cataract risk factors 3, 1, 2.
Clinical Implications
Screening Recommendations
- Screen all diabetic and hypertensive patients for visual symptoms during routine medical visits 1, 2.
- Patients with both conditions require heightened vigilance, as 98.4% of subcapsular cataract patients have at least one cardiovascular or metabolic risk factor 2.
- Be aware that acute hyperglycemia in diabetics can cause transient PSC cataracts with feathery streak-like opacities that may resolve with glycemic control 5.
Management Considerations
- Optimize blood pressure and glycemic control as primary prevention strategies, though direct evidence for cataract prevention through control is limited in these studies 1, 2.
- Consider ophthalmology referral for patients with both diabetes and hypertension who report visual changes, given their 2.66-fold increased risk 1.
- Note that furosemide use in hypertensive patients may further increase cataract risk (OR = 1.95), suggesting alternative antihypertensive agents may be preferable when clinically appropriate 1.
Important Caveats
- Hypertension often progresses undetected for years, making early detection and treatment critical not only for cardiovascular protection but also for potential cataract risk reduction 2.
- In young diabetic patients presenting with acute bilateral PSC cataracts, consider that these may be transient and related to acute hyperglycemia rather than permanent structural changes, warranting glycemic optimization before surgical intervention 5.
- The protective effect of NSAIDs against cataracts appears significant only in hypertensive patients, though this finding requires confirmation 3.