Glaucoma
The Silent Thief of Sight — Early Detection Is Key
Glaucoma — "The Silent Thief of Sight"
Glaucoma is a condition in which the optic nerve is gradually damaged, causing progressive narrowing of the visual field. It is one of the most common causes of irreversible blindness worldwide, and because there are virtually no symptoms in the early stages, it is called "the silent thief of sight."
Once the optic nerve is damaged, recovery is impossible, so the key to treatment is early detection and consistent management to slow the progression of visual field loss as much as possible. Regular glaucoma screening is recommended for anyone over 40.
Types of Glaucoma
The most common form of glaucoma, accounting for approximately 70-80% of all cases. The aqueous humor drainage pathway (trabecular meshwork) is open, but drainage is insufficient, causing intraocular pressure (IOP) to rise gradually, or the optic nerve is damaged even at normal IOP. It progresses very slowly, making it difficult to detect until advanced stages.
- Progresses gradually over years
- Peripheral visual field is lost first
- Affects both eyes, though severity may differ
- Can only be detected early through regular screening
The iris is pushed forward, physically blocking the aqueous humor drainage pathway, causing a rapid rise in IOP. During an acute attack, IOP can surge to 40-80 mmHg, requiring immediate treatment as an ophthalmic emergency.
Acute Angle-Closure Glaucoma Symptoms
- !Sudden severe eye pain and headache
- !Nausea and vomiting
- !Rapid vision loss
- !Eye redness
- !Rainbow-colored halos around lights
- !Fixed, dilated pupil
A form in which the optic nerve is damaged despite IOP being within the normal range (10-21 mmHg). It is particularly common in East Asians, with over 70% of Korean glaucoma patients reported to have normal-tension glaucoma. Since IOP alone cannot diagnose this condition, optic nerve examination and visual field testing are essential.
- Impaired optic nerve blood flow suspected as the main cause
- Associated with low blood pressure, migraines, and Raynaud's phenomenon
- Cannot be detected by IOP testing alone
- OCT optic nerve examination and visual field testing are essential
Symptoms and Risk Factors
General Symptoms of Glaucoma
- Early: Mostly no noticeable symptoms
- Middle: Peripheral visual field gradually narrows
- Late: Tunnel vision (only straight-ahead vision remains)
- Severe: Complete blindness
- The opposite eye compensates, so deterioration in one eye often goes unnoticed
High-Risk Groups for Glaucoma
- Age 40 or older
- Family history of glaucoma
- High myopia (-6D or greater)
- Elevated IOP (21 mmHg or higher)
- Diabetes, hypertension, or cardiovascular disease
- Long-term steroid use
- Thin cornea
Glaucoma Diagnostic Tests
Intraocular Pressure (IOP) Measurement
Precisely measures IOP using Goldmann applanation tonometry or non-contact tonometry. Normal IOP is 10-21 mmHg.
Visual Field Testing
Uses the Humphrey automated perimeter to evaluate the presence and extent of visual field defects. A key test for monitoring glaucoma progression.
OCT Optic Nerve Examination
Precisely measures optic disc and retinal nerve fiber layer (RNFL) thickness using optical coherence tomography to detect early damage.
Gonioscopy
Uses a special lens to observe the structure of the anterior chamber angle (the aqueous humor drainage pathway) and distinguish between open-angle and angle-closure types.
Corneal Thickness Measurement
Corneal thickness can affect IOP readings, so measuring corneal thickness ensures accurate IOP assessment.
Fundus Examination
Evaluates the optic disc shape, cup-to-disc ratio (CDR), and presence of hemorrhages to assess glaucomatous optic nerve damage.
Glaucoma Treatment Options
Medication (Eye Drops)
The primary and first-line treatment for glaucoma. IOP-lowering eye drops are instilled daily to inhibit the progression of optic nerve damage. Various medications including prostaglandin analogs, beta-blockers, alpha-agonists, and carbonic anhydrase inhibitors are used.
Important: Eye drops must be used every day as directed by your doctor. Do not discontinue on your own, even if symptoms are absent, as optic nerve damage may progress.
Laser Treatment
SLT (Selective Laser Trabeculoplasty)
Laser is applied to the trabecular meshwork in open-angle glaucoma to promote aqueous humor drainage. Can be performed on an outpatient basis and is repeatable.
Laser Peripheral Iridotomy (LPI)
A small hole is created in the iris to facilitate aqueous humor flow, used for treatment and prevention of angle-closure glaucoma.
Surgical Treatment
Surgical intervention is performed when medication or laser treatment cannot adequately control IOP.
Trabeculectomy
A traditional glaucoma surgery that creates a new drainage pathway for aqueous humor to lower IOP.
Glaucoma Implant Surgery
A small tube and plate are implanted for aqueous humor drainage. Performed when trabeculectomy has failed or is not feasible.
MIGS (Minimally Invasive Glaucoma Surgery)
The latest minimally invasive surgical technique, causing less tissue damage and faster recovery compared to traditional surgery. Suitable for early to moderate glaucoma and can be performed simultaneously with cataract surgery.
Glaucoma — Early Detection Is the Only Answer
Visual field loss from glaucoma is irreversible, but with early detection and consistent treatment, remaining vision and visual field can be preserved for life. If you are over 40, we recommend a comprehensive glaucoma screening every 1-2 years; if you have a family history or are in a high-risk group, annual screening is advised.