Most people have heard of glaucoma, and you’ve almost definitely heard of cataract surgery, but what’s the real difference between cataracts vs glaucoma? Both cataracts and glaucoma are reasonably common eye conditions but are also very distinctly different. Keep reading to find out what you should know about cataracts vs glaucoma.
Cataracts vs Glaucoma
What are cataracts?
Cataracts are an opacity or haze in the crystalline lens of the eye. At birth, this lens is nice and transparent (barring congenital cataract). However, over the course of time or due to other factors, the lens can become cloudy or develop opacities that block the transmission of light through to the light-sensing retina. The only definitive treatment for cataracts is cataract surgery.
In most cases, cataracts are associated with increasing age and are an entirely normal development. These are known as age-related or senile cataracts.
Cataracts can also be present at birth (congenital cataracts) or be due to other causes such as ocular injury or infection, as a complication of surgery for something else such as a retinal detachment repair, or linked to other diseases such as diabetes.
The symptoms of cataracts can be difficult to identify as they’re somewhat non-specific – that is, other diseases can cause similar symptoms.
In the early stages, cataracts don’t cause any significant symptoms at all. However, as the cataract progresses and the opacities become denser, or the lens becomes cloudier overall, you may begin to notice symptoms such as:
- Hazy sight
- Poorer contrast sensitivity
- Increased difficulty reading in dim lighting
- Increased glare sensitivity
- Increased difficulty driving at night
- Changes to your colour perception
- Frequent changes to your spectacle prescription
Cataract surgery is typically not indicated until these symptoms become bothersome and can no longer be managed with something simple such as updating your glasses or using a reading lamp.
What is glaucoma?
Glaucoma is a type of optic neuropathy, which refers to a disease of the optic nerve. The optic nerve is responsible for carrying neural impulses from the retina to the visual areas of the brain. Damage to this nerve, even if every other part of your eye is healthy, would result in impaired sight.
Most cases of glaucoma are due to an elevated pressure of the eye, known as intraocular pressure. Elevated intraocular pressure is always present in a type of glaucoma called angle closure glaucoma. However, another type of glaucoma, open-angle glaucoma, can occur even in the presence of pressures within normal range; this is typically termed low tension or normotension glaucoma. All therapies for glaucoma, including glaucoma surgery, are aimed at reducing the intraocular pressure in order to protect the optic nerve.
There are almost no symptoms of glaucoma, which is why a significant proportion of adults are thought to be unaware that they’re developing the disease. Concerningly, glaucoma results in a slow, progressive, and permanent loss of sight. This loss begins in the periphery of your field of view. If glaucoma surgery or other glaucoma treatment is not initiated in time, your visual field could constrict into tunnel vision or result in total loss of sight.
The exception to this is acute angle closure when the intraocular pressure spikes very high. This can result in a painful, red eye, haloes around lights, and is associated with nausea and vomiting.
Cataracts vs Glaucoma Treatment
For the treatment of cataracts, cataract surgery is the only option. Cataract surgery is the most common ophthalmic procedure in the world. During this operation, an incision is made in the cornea under topical anaesthesia. Through the incision, tools can be inserted to access the cataract to fragment it into smaller pieces, which are then removed from the eye. An artificial intraocular lens is inserted in the place of your natural lens. One of the benefits of cataract surgery, other than getting rid of the cataract, is that the intraocular lens can be calculated to correct your eye’s prescription. This means that you can be free of glasses and contacts after your cataract surgery, whether for far-distance sight, near-reading sight, or both.
Conversely, glaucoma surgery doesn’t tend to be the first-line treatment for glaucoma. Instead, many patients with open-angle glaucoma are commenced on pressure-lowering eyedrops rather than glaucoma surgery. If eyedrops are ineffective or cause intolerable side effects, a laser procedure tends to be the next option before glaucoma surgery is considered. This laser procedure aims to stimulate increased fluid outflow through the eye’s drainage channels, which reduces the intraocular pressure. In some situations, cataract surgery can also be an effective treatment for glaucoma because extracting the cataract assists in increased fluid drainage. If this is the case, your surgeon may suggest cataract surgery even if your cataracts are not particularly symptomatic.
If eyedrops and laser therapy are both ineffective at slowing or stopping the progression of optic nerve damage, your ophthalmologist may recommend glaucoma surgery. Glaucoma surgery encompasses a number of procedures, such as inserting a shunt or stent or creating another channel to encourage the outflow of aqueous fluid and reduce the intraocular pressure.
Because nothing can restore sight that is lost from glaucomatous optic neuropathy, it’s important to initiate appropriate treatment as soon as possible, whether with eyedrops, laser therapy, or glaucoma surgery. As with all surgical operations, glaucoma surgery can be associated with some risk of complications, such as inducing inflammation or the intraocular pressure dropping too low. However, if your surgeon believes glaucoma surgery to be the best option for you, it will only be if the benefits of managing glaucoma and preserving your remaining sight outweigh the potential risk of complications.
Contact us now on (03) 9070 5753 for a consultation.
Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.
What’s the Difference Between Glaucoma and Cataracts?
Current Options for Surgical Treatment of Glaucoma.