Introduction

The macula (macula lutea) is a tiny area in the centre of the retina that determines our ability to see the world clearly and in detail. Thanks to the macula, we can read small print, drive a car, recognise faces, and distinguish the finest shades of colour.

When problems arise with the macula — whether age‑related changes, swelling, or a micro‑tear (macular hole) — the quality of central vision deteriorates significantly. This article explains where the macula is located, how it is structured, what functions it performs, and which diseases can affect it.

What Is the Macula and Where Is It Located?

The macula is a specialised area of the retina, situated on the back wall of the eyeball (the fundus). It appears as a small yellowish area due to a high concentration of light‑sensitive pigment.

Key facts:

• Location: exact centre of the retina.
• Colour: yellowish spot (from Latin macula — “spot”).
• Function: converts light impulses into nerve signals that the brain turns into detailed images.

The Retina and the Ocular Fundus

The retina is the inner layer of the eye responsible for light perception. The macula occupies only a small part of it, but it provides the highest quality and sharpest vision. When an ophthalmologist examines the fundus, they evaluate the condition of the macula first.

Why Is the Macula So Important for Vision?

Without a healthy macula, everyday tasks become extremely difficult. This area of the retina gives us:

• High visual acuity — the ability to see fine details (letters, threads, road cracks).
• Colour perception — distinguishing shades and colour saturation.
• Central vision — the ability to focus directly on the object we are looking at.

If the macula is damaged, peripheral vision may remain good, but a person loses the ability to see what they are looking at directly.

Structure of the Macula

The macula is not just a “spot” — it is a complexly organised structure with several zones:

Fovea (Central Fovea)

Located in the very centre of the macula (diameter about 1.5 mm). This is the key area for sharpest vision. It has the highest density of cones — photoreceptors responsible for colour and detail.

Foveola

A depression inside the fovea (diameter about 0.35 mm). It appears as a small shiny reflex. The foveola provides the maximum possible visual acuity.

Foveal Avascular Zone (FAZ)

An area inside the fovea with no blood vessels. This allows light to reach the photoreceptors without any interference. On angiograms, this zone looks darker than the surrounding tissue.

Parafoveal Zone

The area surrounding the fovea (width about 0.5 mm). This is the thickest part of the retina.

Perifoveal Zone

The outer edge of the macula (diameter about 3.5 mm). A transitional area from central to peripheral vision.

Functions of the Macula

The macula performs several critically important tasks that go far beyond simple “seeing”.

High Resolution

Thanks to the high density of cones in the fovea, the macula allows us to distinguish the finest details: reading small fonts, seeing fabric textures, noticing tiny defects.

Colour Perception

Cones in the macula are specialised to detect different wavelengths of light (red, green, blue). Without a healthy macula, the world becomes dull and colours lose their saturation.

Motion Detection

The macula instantly transmits information about moving objects in the visual field to the brain. This is essential for driving, playing sports, and reacting to rapid changes in the environment.

Binocular Coordination (Stereopsis)

The macula is the fixation point for each eye. The brain combines signals from the right and left maculae into a single three‑dimensional image, allowing us to judge depth, distance, and volume.

Macular Diseases

Diseases of the macula severely reduce quality of life because they affect central vision directly. The most common conditions are listed below.

Age‑Related Macular Degeneration (AMD)

The most common macular disease, especially in people over 65. It involves progressive thinning or abnormal tissue growth in the centre of the retina. Peripheral vision usually remains, but reading, recognising faces, and watching television become impossible.

Macular Oedema

Fluid accumulation within the macula. The most common cause is diabetes mellitus (diabetic macular oedema). It can also occur with retinal vein occlusion, uveitis, after eye surgery, or as a side effect of certain medications. Symptoms: blurred vision, distortion of straight lines.

Macular Hole

A microscopic tear in the centre of the macula. Most often caused by traction (pulling) of the vitreous gel, which is normally attached to the retina. The disease has 4 stages:

• Stage 1 — may be asymptomatic.
• Stages 2–3 — distortion and vision loss appear.
• Stage 4 — significant loss of central vision (a dark spot in the centre).

Epiretinal Membrane (Macular Pucker)

A thin transparent membrane forms on the surface of the macula. Over time, it contracts and wrinkles the retina, causing image distortion (straight lines appear wavy). Early stages may be unnoticed, but as it progresses, reading becomes difficult and a dark spot may appear in central vision.

What to Do If You Suspect a Macular Problem

Any of the conditions described above requires immediate consultation with an ophthalmologist specialising in retinal diseases. Self‑diagnosis and delayed treatment can lead to irreversible central vision loss.

Symptoms to watch for:

• Reduced sharpness of central vision.
• Distortion of straight lines (windows, door frames, lines of text).
• A dark or hazy spot in the centre of your vision.
• Difficulty reading or recognising faces.

If you notice any of these symptoms — do not delay a visit to a specialist.

How Can Valenia Health Services Help?

Valenia Health Services specialises in arranging medical care for international patients in the best clinics of Barcelona. We work with leading ophthalmology centres in the city that successfully treat all types of macular pathology — from age‑related degeneration to macular holes and epiretinal membranes.

What we offer:

• Selection of the best retina specialist for your clinical case.
• Full organisation of diagnostics and treatment in Barcelona — no waiting lists, no language barriers.
• Professional medical translation and support at every stage.
• Transparent pricing — you pay only the clinic’s medical invoice, with no hidden fees.

We do not perform treatment ourselves, but we guarantee that you will see the best specialists in Spain, receive an accurate diagnosis, and get modern treatment.

Conclusion

The macula is a unique and extremely vulnerable structure of the eye. It makes our vision sharp, colourful, and detailed. Any macular disease, even at an early stage, requires specialist attention.

Timely diagnosis and proper treatment, organised in leading ophthalmology centres in Barcelona, can preserve vision for many years.

Contact Valenia Health Services. We will help you preserve your vision.

At Hospital Universitari de Bellvitge, a complex surgical procedure was successfully performed using a pioneering technique that enabled the complete removal of a pancreatic tumor involving major blood vessels. Advanced surgical planning and vascular reconstruction made it possible to preserve blood flow and significantly reduce the risk of complications.

Similarly, Hospital Universitari Vall d’Hebron, one of Spain’s leading oncology centers, applies a multidisciplinary approach to the treatment of locally advanced pancreatic cancer, combining highly specialized surgery with modern systemic therapies.

These advances represent a real expansion of therapeutic options and provide new treatment opportunities for patients who previously could only receive palliative care.

A scientific team has developed a combination therapy involving several drugs that, in preclinical studies, demonstrated the complete elimination of pancreatic tumors in experimental models. Notably, no tumor recurrence was observed after treatment, and side effects were minimal.

This therapeutic approach targets key molecular mechanisms responsible for tumor growth and resistance, including mutations considered central to the development of this type of cancer.

Although these results are currently limited to experimental (non-human) studies, they are regarded by the scientific community as highly promising and provide a strong foundation for future clinical trials.

This breakthrough opens new perspectives and offers hope for the development of more effective treatments in the future.

The patient, a six-year-old girl, was born with a rare condition known as corneal anesthesia, caused by underdevelopment of the trigeminal nerve. As a result, her eyes lacked sensitivity and protective reflexes, such as blinking, leaving them vulnerable to repeated injuries, corneal ulcers and progressive vision loss. Over time, the condition led to the loss of up to 90% of her visual capacity.

After conventional treatment options proved ineffective, the medical team opted for an innovative corneal neurotization technique, a highly specialized surgical procedure available only in a limited number of centers worldwide. The surgery involves transplanting a segment of a peripheral nerve and connecting it to a sensory facial nerve, allowing corneal sensitivity to gradually recover. The intervention was performed in stages, starting with one eye.

Several months after the operation, doctors observed a clear improvement. With the support of specialized scleral contact lenses, the child began to recognize objects and details in her environment. The frequency of ocular complications and emergency visits decreased significantly, and her overall quality of life improved. Specialists believe that further recovery may be possible over time.

This case illustrates why Spain has become an important destination for international patients seeking complex and innovative medical treatments. The combination of cutting-edge technology, multidisciplinary medical teams and experience with rare conditions enables Spanish hospitals to successfully treat patients from abroad, including children with highly complex diagnoses.

For international patients and families, Spain offers not only high medical standards, but also structured care pathways covering diagnosis, treatment and follow-up. Stories like this demonstrate how medical treatment abroad, when properly organized, can make a meaningful difference in patients’ lives and long-term outcomes.

What does this mean?

In particularly complex cases — such as severe dry eye, chemical burns, congenital aniridia, or autoimmune diseases — oral mucosa can be used as an additional covering. This helps improve treatment outcomes and reduce the risk of complications, such as implant extrusion.

Why is this important?

• A more accessible alternative compared to other methods (e.g., osteo-odonto-keratoprosthesis).
• Less steep learning curve for surgeons.
• Provides better cosmetic results.
• Preserves the possibility of future retinal or glaucoma surgeries.

Conclusion

The combination of the Boston keratoprosthesis with oral mucosa represents a simpler, safer, and more aesthetically favorable option for patients who previously had very limited alternatives.

An example of how surgical innovations continue to transform ophthalmology and improve patients’ quality of life.

This recognition solidifies Teknon’s leadership in the field of private healthcare, in a year when it shares the ranking with major reference institutions such as the Hospital Clínic de Barcelona, the Fundación Jiménez Díaz University Hospital, and La Paz Hospital. The publication highlights the advances driven by Teknon, notably the creation of its Oncology Institute, robotic surgery with the Da Vinci system, a hybrid operating room, Spain’s first open high-field magnetic resonance imaging machine, the Heart Institute, and the Neuroscience Institute.

Furthermore, Centro Médico Teknon holds international accreditation from the Joint Commission International, renewed for the seventh consecutive time since 2002—a distinction only awarded to healthcare centers that meet the world’s most demanding standards of quality and patient safety.

In 2024, the hospital celebrated its 30th anniversary, reaffirming its commitment to innovation, treatment personalization, and the well-being of its patients. This new recognition reinforces its position as a leading hospital center in Catalonia and throughout Spain.

The 2025 hospital ranking by Forbes identifies the top 25 leading centers in Spain, both public and private, based on an analysis of various international indices, awards received, level of innovation, recent clinical milestones, and patient ratings. Now in its third consecutive year, this ranking has become a benchmark in the healthcare sector by highlighting hospitals that make a difference through their excellence in care, commitment to research, and ability to incorporate cutting-edge technologies in the service of health.

What determines our eye color?

Our eye color depends on the amount and distribution of a pigment called melanin in the iris — a fibromuscular tissue that forms the pupil diaphragm. There are two types of melanin: eumelanin (dark brown) and pheomelanin (reddish-brown). Depending on how much melanin is present in the iris epithelium and stroma, and the density of these tissues, the eye acquires a specific color.

What are the most common eye colors and why?

Globally, brown is the most common eye color, except in Europe, where a variety of colors such as hazel, green, blue, and gray appear. Initially, it was believed this was linked to genes that control skin pigmentation, but there’s no clear connection in most cases.

Some theories attributed this to genetic mixing with Neanderthals, but the limited gene flow doesn’t explain the high incidence of non-brown eyes in Europe. Other geneticists suggest it’s due to sexual selection: when one sex outnumbers the other, individuals compete for mates using traits like bright or unusual eye colors to attract attention.

Can we change our eye color?

Many people have a cosmetic desire to change their eye color, but achieving it is not simple. There are both reversible and irreversible techniques.

The simplest and most reversible method is cosmetic contact lenses, available in many colors. They provide excellent cosmetic results but must be used carefully to avoid complications such as conjunctivitis or serious corneal infections.

Among permanent solutions, there are surgical methods like keratopigmentation, or corneal tattooing. This involves creating a small circular pocket inside the cornea with a femtosecond laser and filling it with colored pigments, producing a convincing cosmetic effect.

Keratopigmentation is also used therapeutically in pathological eyes to correct iris defects.

Another technique involves iris depigmentation using a special laser that removes melanin and lightens the iris color. Artificial irises were also designed and implanted in front of the natural iris, but most cases had disastrous outcomes.

Are these techniques safe? What are the risks?

Laser depigmentation carries the highest risk. The laser releases pigment into the eye’s aqueous humor, which can clog the drainage meshwork and raise intraocular pressure, potentially causing glaucoma. If uncontrolled, this can lead to irreversible optic nerve damage and vision loss.

Keratopigmentation, being performed on the cornea, may cause minor changes in vision, affect night or peripheral vision, and complicate future intraocular surgeries. Long-term pigment tolerance and degradation are also important concerns. Though less aggressive, it still carries potential risks.

What is the ophthalmology community’s opinion?

Most ophthalmologists oppose elective eye color change surgery on healthy eyes due to the unacceptable risks. Laser depigmentation and artificial iris implants have been largely abandoned due to their serious complications.

In contrast, cosmetic keratopigmentation is being performed in a few international centers. However, the lack of long-term, peer-reviewed studies in prestigious ophthalmology journals — despite some positive conclusions — prevents widespread acceptance.

On the other hand, keratopigmentation for pathological cases is considered fully justified when it solves issues that impair a patient’s visual quality, such as partial or total loss of the iris.

As for cosmetic keratopigmentation, since it remains rare and controversial, caution is advised. Long-term results are needed to determine whether the procedure is truly safe and what complication rates exist, so that patients can be properly informed.

Medical article by Dr. Juan Álvarez de Toledo

What Is Buttock Lipofilling?

Buttock lipofilling is a surgical procedure that involves extracting fat from specific areas of the body (such as the abdomen, flanks, or thighs) and injecting it into the buttocks to enhance their shape and volume. This not only improves the silhouette but also sculpts the body by reducing unwanted fat in other areas.

It is a more natural alternative to implants since it uses the patient’s own tissue, eliminating the risk of rejection and promoting faster recovery.

Our technique focuses not only on adding volume to the buttocks but also on harmoniously reshaping the entire area. During preoperative planning, special attention is given to the flanks—sculpting them through liposuction significantly enhances the buttocks’ appearance. The hips are also carefully contoured.

After harvesting and processing the fat, lipofilling is performed to achieve the desired projection and shape of the buttocks.

Benefits of Buttock Lipofilling

• Natural Results – Since the patient’s own fat is used, the buttocks look and feel completely natural.
• Full Body Sculpting – In addition to enhancing the buttocks, the procedure creates a slimmer silhouette by removing excess fat from other areas.
• Minimal Risk of Rejection – The body does not reject its own fat, reducing complications.
• Customizable Outcomes – The procedure is tailored to each patient’s body proportions and aesthetic goals.

How Is the Procedure Performed?

Buttock lipofilling consists of three main stages:

• Liposuction – Fat is gently extracted via cannula from areas like the abdomen, lower back, flanks, or thighs.
• Fat Purification – The harvested fat is processed to remove impurities, leaving only healthy fat cells for transfer.
• Fat Injection – The purified fat is strategically injected into the buttocks to create the desired volume and shape.

The entire procedure is performed under strict sterile conditions, using either general or local anesthesia, depending on the extent of surgery.

Who Is an Ideal Candidate for Buttock Lipofilling?

The best candidates are those who:

• Have excess fat in other body areas.
• Desire a moderate increase in buttock volume.
• Prefer a natural-looking enhancement.
• Are in good overall health without conditions that increase surgical risks.

How Long Do the Results Last?

The results are long-lasting but require proper care. Approximately 70–80% of the transferred fat remains permanently, while the rest may be naturally absorbed in the first few months. Maintaining a stable weight and a healthy lifestyle helps preserve the outcome.

Lipofilling vs. Implants: Which Is Better for Buttock Augmentation?

One of the biggest questions for those seeking a better buttock shape is: Should I choose implants or fat transfer?

• Buttock Implants – Use silicone prostheses for added volume. Suitable for patients with insufficient fat or those seeking a more dramatic enhancement. However, implants may feel less natural and carry risks like displacement or rupture.
• Lipofilling (Fat Transfer) – Uses the patient’s own fat, providing a softer, more natural look and feel. An added benefit is body contouring through fat removal from other areas. Results are more subtle but harmonious.

Both methods have advantages, and the choice depends on aesthetic goals, body type, and the surgeon’s recommendation.

The “World Best Hospitals 2025” ranking is one of the most renowned globally. Its methodology combines:

• The opinions of tens of thousands of healthcare professionals from 30 countries.
• Patient evaluations collected through experience surveys.
• Objective indicators of hospital quality.
• Assessment of the implementation of PROMs (Patient-Reported Outcome Measures), which measure how patients perceive their health status after receiving treatment.

This rigorous process ensures that the hospitals highlighted in the ranking are benchmarks in care excellence, innovation, and patient experience.

Centro Médico Teknon’s prominent position in this ranking reflects the center’s ongoing commitment to implementing cutting-edge medical technology, a multidisciplinary team of renowned specialists, and patient-centered healthcare that focuses on both the technical and human aspects of each process. It also underscores the center’s continuous pursuit of clinical excellence and improved health outcomes.

Centro Médico Teknon is part of Quirónsalud, the leading private healthcare group in Spain. Quirónsalud has the strongest presence in the Newsweek ranking, with a total of 10 hospitals recognized among the top 100 in Spain. Nine of these are in the top 50, confirming the group as an undisputed leader in private healthcare in the country.

For Centro Médico Teknon, this recognition is a source of pride and also a motivation to continue improving. The center remains committed to technological innovation, advancing medical research, enhancing the patient experience, and ensuring the delivery of excellent healthcare services.