ABSTRACT
Glaucoma
is one of the leading causes of irreversible blindness worldwide, affecting
millions of people. It is characterized by a heterogeneous group of conditions
that cause damage to the optic nerve, often associated with increased
intraocular pressure (IOP). This article reviews the main causes of glaucoma,
such as genetic factors, age and systemic conditions, as well as current
treatments, including pharmacological therapies, laser procedures and
surgeries. A global and interdisciplinary approach is essential for the
effective prevention and management of the disease. Research highlights
promising advances in personalized treatments and a deeper understanding of the
underlying mechanisms of glaucoma, emphasizing the importance of public health
strategies to reduce its prevalence.
Keywords:
Glaucoma; Blindness; Irreversible; Neurodegenerative; Optic nerve
INTRODUCTION
Glaucoma is a chronic neurodegenerative disease that
represents a significant global public health challenge. According to the World
Health Organization (WHO), it is estimated that 80 million people worldwide are
affected by glaucoma, with projections indicating an increase due to population
aging1,2. The primary hallmark of
glaucoma is progressive damage to the optic nerve, leading to visual field loss
and potentially progressing to irreversible blindness if not adequately
treated. Although elevated IOP is the main risk factor, many cases occur in
individuals with normal intraocular pressure3,
highlighting the disease's multifactorial complexity. Risk factors such as
advanced age, family history, myopia, ethnic background and systemic conditions
like diabetes and hypertension contribute to glaucoma susceptibility4. The disease can also be classified into
different types, including open-angle glaucoma, angle-closure glaucoma,
congenital glaucoma and secondary glaucoma, each with distinct
pathophysiological mechanisms5. The
primary goal of glaucoma treatments is to reduce IOP to prevent further optic
nerve damage6. Approaches include the
use of eye drops, laser therapies and surgical procedures such as
trabeculectomy and drainage devices7.
Recently, research into neuroprotective therapies and regenerative medicine has
shown significant advances in glaucoma management8.
OBJECTIVE
This
study aims to analyze the main causes of glaucoma on a global scale and review
current treatments, highlighting their effectiveness, limitations and barriers
to access, with a focus on blindness prevention.
MATERIALS
AND METHODS
This
study consists of a bibliographic review based on articles indexed in the
PubMed, Scopus and Web of Science databases.
DISCUSSION
Glaucoma is a multifactorial disease with
widely studied but not fully understood causes. Among genetic factors,
mutations in the MYOC gene, which encodes myocilin and the OPTN gene, related
to optineurin, have been linked to hereditary forms of primary open-angle
glaucoma (POAG). Population studies show that individuals of African descent
are more predisposed to POAG, while primary angle-closure glaucoma (PACG) is more
common in Asian populations. These racial factors underscore the importance of
tailoring therapeutic approaches to population characteristics. Systemic risk
factors such as diabetes and hypertension also play significant roles. Studies
suggest that chronic hyperglycemia can damage retinal ganglion cells,
contributing to optic neuropathy. Myopia, in turn, is associated with
anatomical changes that increase glaucoma susceptibility. Additionally, factors
such as corticosteroid exposure, intraocular inflammation and ocular trauma
deserve attention as they can trigger secondary glaucoma cases9.
Significant advances have been made in
pharmacological treatments. Prostaglandin analogs, such as latanoprost and
bimatoprost, remain the first-line treatment due to their effectiveness in
lowering IOP. However, adherence to treatment remains a challenge, primarily
due to side effects and the need for daily application. Laser procedures, such
as selective laser trabeculoplasty, offer minimally invasive solutions,
especially for patient’s intolerant to medications10. Recent studies suggest that laser trabeculoplasty can be an effective
initial treatment option. In refractory cases, surgeries such as trabeculectomy
and drainage devices remain the gold standard, although they carry risks like
infections and hypotony11,12. An area of growing interest is
neuroprotection. Therapies aimed at protecting retinal ganglion cells and the
optic nerve have been explored in preclinical and clinical studies. Compounds
such as citicoline and brimonidine show promising potential, though further
research is needed for validation13. Despite advances, challenges persist. Low
treatment adherence, particularly in low-income regions, limits the
effectiveness of interventions. Additionally, the lack of early diagnosis
remains a critical barrier14, as glaucoma is often asymptomatic in its
early stages. Awareness campaigns and population screening can play a vital
role in improving this scenario15.