The ability to see clearly is one of our most precious senses however the human eye is structurally intricate and functionally complex in nature and it can be susceptible to various forms of conditions and diseases including glaucoma and cataracts.
Both glaucoma and cataracts can affect out vision and independence however they are different in many ways. For example, glaucoma is a condition that affects the optic nerve and optic disc at the back of the eye while cataracts is a condition that affects the lens at the front of the eye.
Find out more about glaucoma and cataracts, understand which condition you may have, learn which is worse, and whether it is safe to have cataract surgery with glaucoma.
Glaucoma vs Cataracts: What's the difference?
Cataracts and glaucoma are two of the most common conditions that can threaten our sight, and are leading causes of blindness worldwide.
However, they are fundamentally different diseases in how they affect our vision, how they are diagnosed and how they are managed.
Differences between cataracts and glaucoma include:
Cataract
Clouding and hardening of the natural crystalline lens.
Lens (crystalline lens) at the front of the eye.
Minimal to cloudy, foggy vision, glare sensitivity, even with best corrected glasses.
Some patients notice large changes in their spectacle prescription between checks (“Why aren’t my glasses right?”).
Example of cloudy vision a person see with cataracts.
Visual acuity, refraction, intraocular pressure, dilated fundus examination.
Surgery – very effective, option of monofocal, multifocal, and monovision if suitable.
Surgery effectively treats this condition.
Glaucoma
Irreversible damage to the optic nerve, usually related to raised intraocular pressure (IOP).
Optic nerve at the back of the eye.
Open angle glaucoma – no symptoms to progressively constricted visual field.
Closed angle – can be asymptomatic but usually redness, pain, nausea/vomiting and blurry vision.
Example of peripheral vision loss caused by glaucoma.
Visual acuity, corneal pachymetry, gonioscopy, intraocular pressure, dilated fundus examination, and visual field examination.
Medications with glaucoma eye drops. Surgery to lower intraocular pressure.
Medications effective in intraocular pressure control if taken correctly, surgery can be used to augment the intraocular pressure reduction.
Vision defects depend on the intraocular pressure control.
Open angle glaucoma – generally not, but significant nerve damage can occur within weeks if pressure is elevated.
Closed angle glaucoma – Yes! Seek urgent medical attention.
Which is Worse: Glaucoma or Cataracts?
No one disease is worse than the other, as glaucoma tends to affect the peripheral vision and cataracts affects total vision. However, early detection is key particularly with glaucoma as any vision lost due to damage to the optic nerve is irreversible.
Glaucoma and cataracts can develop together or independently of one another and will affect an individual’s vision differently based upon their environment, sensitivity to blurry vision blur, and the severity of their condition.
The good news is that there are management options for both glaucoma and cataracts, especially if caught early.
Is it safe to have cataract surgery with glaucoma?
In time, most people will need cataract surgery to restore their vision, and this includes patients with glaucoma.
Cataract surgery is generally considered safe for patients with glaucoma however these patients may require extra attention to monitor for changes in intraocular pressure during and after the operation.
Glaucoma procedures such as selective laser trabeculotomy (SLT) can be done before or after cataract surgery. While some patients with glaucoma may benefit from combining cataract surgery with the insertion of stent devices, as these stents assist with the reduction of intraocular pressure.
Other glaucoma surgeries such as glaucoma tube surgery, trabeculectomy, cyclodiode are often performed after cataract surgery.
Glaucoma vs Cataracts: A Quick Summary
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• Impacts the optic nerve at the back of the eye
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• Damage generally caused by raised pressure inside the eye - intraocular pressure (IOP)
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• Early detection critical as no symptoms experienced until permanent vision loss occurs
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• Causes irreversible vision loss and can cause blindness if left untreated
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• Treatment is to lower intraocular pressure to prevent further damage to the optic nerve
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• Rapid or slow progression depending on the type of glaucoma
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• Some cases, especially angle closure glaucoma, are ocular emergencies - they require urgent medical attention to prevent rapid and significant vision loss or blindness
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• Impacts the lens at the front of the eye behind pupil and iris
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• Natural lens of the eye becomes progressively cloudy and inflexible
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• Cataracts generally can be monitored over time by your eye specialist with no significant reduction in good outcomes
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• Vision loss can be restored through cataract surgery
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• Surgery is to replace the cloudy natural lens with a clear artificial lens – intraocular lens (IOL)
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• Cataracts generally progress slowly, becoming cloudier and more visually bothersome