Why Choose
Assoc. Prof. Dr. Efekan Coşkunseven for Keratoconus?

Assoc. Prof. Dr. Efekan Coşkunseven served as an Ophthalmology Specialist at Dünya Göz Hospital for 28 years, from May 1996 to December 2023, and held the position of Head of the Refractive Surgery and Keratoconus Diagnosis and Treatment Center from 2003 to 2023.

In 1998, he became Turkey's first Intacs (intracorneal ring) certified physician.

In 2004, he performed Turkey's first intracorneal ring implantation using the IntraLase femtosecond laser.

Also in 2004, Dr. Efekan Coşkunseven performed Turkey's first corneal collagen cross-linking (CXL) procedure. That same year, he established Turkey's first dedicated Keratoconus Diagnosis and Treatment Center.

In 2009, he introduced topography-guided laser treatments following CXL.

In 2010, he received an award at the American Society of Cataract and Refractive Surgery (ASCRS) Congress for his work on a triple-therapy combination approach involving keratoconus, CXL, and topography-guided laser treatment.

In 2023, he chaired the International Intracorneal Ring Segment Treatment session at the ESCRS (European Society of Cataract and Refractive Surgeons) Congress.

He holds a patent for intrastromal corneal ring segments in keratoconus. He is an internationally certified physician trainer in intracorneal ring procedures and phakic implantable contact lenses. His awards include the ESCRS 500 TICL Award, the Evo Visian 1000 TICL Award in 2016, the Evo Visian ICL Ambassador Award and Evo Visian Excellence Award in 2017, and the Evo Visian Regional Contribution to Scientific Publications Award in 2022.

His research and clinical work on ICRS, CXL, topography-guided laser treatment, keratoconus, and phakic IOL combinations have been presented and published at numerous international congresses and in peer-reviewed academic journals.

He has authored more than 150 international publications on keratoconus, cataract, and refractive surgery, contributed as a co-author to 5 books, and has served as a live surgery presenter, instructor, session chair at international meetings, and reviewer and editor for international journals.

Why Choose
Assoc. Prof. Dr. Efekan Coşkunseven for Keratoconus?

Assoc. Prof. Dr. Efekan Coşkunseven served as an Ophthalmology Specialist at Dünya Göz Hospital for 28 years, from May 1996 to December 2023, and held the position of Head of the Refractive Surgery and Keratoconus Diagnosis and Treatment Center from 2003 to 2023.

In 1998, he became Turkey's first certified Intacs (intracorneal ring) surgeon.

In 2004, he performed Turkey's first IntraLase femtosecond laser-assisted intracorneal ring implantation.

Also in 2004, Dr. Efekan Coşkunseven performed Turkey's first corneal collagen cross-linking (CXL) procedure. That same year, he founded Turkey's first Keratoconus Diagnosis and Treatment Center.

In 2009, he introduced topography-guided laser (TopoLaser) treatments following CXL.

In 2010, he received an award at the American Society of Cataract and Refractive Surgery (ASCRS) congress for his research on a triple-therapy combination of keratoconus treatment, CXL, and TopoLaser.

At the 2023 ESCRS (European Society of Cataract and Refractive Surgeons) meeting, he chaired the International Intracorneal Ring Segments session.

He holds a patent for intrastromal corneal ring segments in keratoconus. He is an internationally certified trainer in intracorneal ring applications and phakic implantable contact lenses. His awards include the ESCRS 500 TICL Award, the 2016 EVO Visian 1000 TICL Award, the 2017 EVO Visian ICL Ambassador Award, the EVO Visian Excellence Award, and the 2022 EVO Visian Regional Contribution to Scientific Publications Award.

His research and clinical work on intracorneal ring segments (ICRS), CXL, TopoLaser, keratoconus, and phakic intraocular lens combinations have been presented and published at numerous international congresses and in peer-reviewed academic journals.

He has authored more than 150 international publications on keratoconus, cataract, and refractive surgery, contributed as co-author to 5 books, and served as a speaker and live surgery demonstrator at international meetings. He has also held roles as session chair, peer reviewer, and editorial board member for international ophthalmic journals.

About

Keratoconus Treatment

Keratoconus is a progressive eye disease in which the cornea — the transparent outermost layer of the eye — gradually thins and assumes a cone-like shape. This abnormal curvature prevents light from refracting properly, resulting in blurred or distorted vision. Keratoconus typically develops in early adulthood, and the rate of progression varies from person to person.

The thinning and irregular shaping of the cornea leads to visual disturbances such as myopia and astigmatism.

As the disease progresses, vision may no longer be adequately corrected with glasses or standard soft contact lenses.

Keratoconus most commonly affects both eyes, although the severity may be greater in one eye

than the other.

Keratoconus Videos

Why Early Diagnosis Matters
in Keratoconus

Why Are Regular Eye Examinations
Important in Keratoconus?

What Measures Can Be Taken
to Prevent Keratoconus
from Reaching
an Advanced Stage?

What Problems Does
Keratoconus
Cause?

Keratoconus: Causes and Risk Factors

01

Genetic Factors

Keratoconus may have a genetic predisposition. Individuals with a family history of keratoconus carry a higher risk of developing the condition.

For this reason, genetic factors are thought to play a significant role in the disease.

02

Eye Rubbing Habit:

Frequent and vigorous eye rubbing is one of the significant factors that increase the risk of keratoconus. The habit of rubbing the eyes is particularly common in individuals with allergic eye disease or chronic eye itching. Over time, this habit can lead to progressive weakening and thinning of the corneal structure.

03

Environmental and Hormonal Factors

Keratoconus tends to begin during puberty and may progress through early adulthood.

This suggests that hormonal changes may play a role in the development of keratoconus.

Additionally, certain environmental factors — such as prolonged exposure to UV light — may increase the risk of keratoconus.

04

Association with Connective Tissue Disorders

Individuals with certain connective tissue disorders — such as Marfan syndrome and Ehlers-Danlos syndrome — carry a higher risk of developing keratoconus.

These conditions can weaken the collagen structure, leading to progressive deterioration of the cornea.

Keratoconus Treatment Options

1. Keratoconus Glasses and Contact Lenses

Glasses: In the early stages of keratoconus, patients can often achieve good vision with glasses. However, as the disease progresses and corneal surface irregularity increases, glasses alone become insufficient.

Contact Lenses: Contact lenses are generally the first choice for correcting vision in keratoconus. Depending on the stage of the disease and the individual eye structure, different lens types may be preferred. These include rigid gas-permeable contact lenses, hybrid contact lenses, scleral contact lenses, and specialized soft silicone hydrogel contact lenses designed for keratoconus. By reducing corneal surface irregularities, these lenses help improve visual quality. The most suitable lens is determined through a thorough fitting process conducted together with the patient.

2. Keratoconus Corneal Cross-Linking (CXL)

Corneal cross-linking is performed to increase the structural strength of the cornea. By applying riboflavin (vitamin B2) drops and ultraviolet (UV-A) light, the collagen cross-links within the cornea are reinforced. Cross-linking is the most effective method available for halting the progression of keratoconus.

Advantages: It can stop disease progression, particularly when applied at an early stage. A modest improvement in visual quality may also be achieved.

3. Intracorneal Ring Segments and CAIRS (Keranatural) Treatments:

a)Intracorneal Ring Segments (ICR): In moderate stages of keratoconus, ring segments (such as Intacs or Keraring) can be implanted within the cornea. These rings help reshape the cornea into a more symmetric profile, thereby improving visual quality.

  • Advantages: By preserving the central cornea, they can enable better vision with contact lenses or glasses. The procedure is reversible for most patients.

b) CAIRS Segments (Keranatural): CAIRS segments are derived from human donor corneas, and their preparation varies depending on the surgeon's preference and available resources. There are two main sources and preparation pathways:

  1. Pre-packaged segments from dedicated eye banks: Eye banks such as Lions VisionGift supply pre-cut, sterilized stromal segments (e.g., KeraNatural®) that arrive ready for use. These implants, which have an extended shelf life, eliminate the need for intraoperative customization and reduce variability in graft quality.
  2. Custom-prepared donor tissue: Corneal rims obtained from eye banks are processed manually by the surgical team. After removing the epithelium, Descemet's membrane, and endothelium, the remaining stromal tissue is cut using a trephination technique to form ring segments. These segments can then be trimmed and customized according to the patient's corneal topography. Surgeons can adjust everything from arc length and thickness to taper and curvature, depending on the location and severity of the cone.
  • Advantages: By preserving the central cornea, they can enable better vision with contact lenses or glasses. The procedure is reversible for most patients.

4.Topography-Guided Laser Treatment: This procedure uses a specialized excimer laser device that acquires a topographic map of the eye and applies that data to correct corneal steepening. This treatment is particularly effective when combined with cross-linking — either performed simultaneously or six months apart. The most recent scientific studies indicate that treatments performed six months apart yield more predictably planned outcomes. Combining cross-linking, ring segment implantation, and topography-guided laser therapy can produce excellent results. Our related study was awarded Best Paper at the American Society of Cataract and Refractive Surgery (ASCRS) meeting in 2010.

5. Implantable Contact Lens (ICL) Implantation
For more than 25 years, implantable contact lens surgery — placing a new lens inside the eye without removing the eye's natural lens — has been performed worldwide and in Turkey for the treatment of high myopia, hyperopia, and astigmatism. This approach is also used to treat high myopia and astigmatism that develop as a consequence of keratoconus. Particularly when combined with cross-linking to halt disease progression, ring segments to correct corneal steepening, and topography-guided laser treatment, this method consistently delivers excellent outcomes.

6. Corneal Transplantation (Keratoplasty) in Advanced Stages

    • In advanced keratoconus, when the cornea becomes severely thinned, develops scar tissue, or no longer responds to other treatments, corneal transplantation may be necessary. Healthy donor corneal tissue is transferred to the patient through surgical techniques such as penetrating keratoplasty (full-thickness corneal transplantation) or deep anterior lamellar keratoplasty (DALK).

    • Advantages: These procedures can provide long-term good visual outcomes in patients with advanced keratoconus.

Advanced Keratoconus Treatments

As keratoconus progresses, more invasive treatments may become necessary. When glasses and contact lenses are no longer sufficient,

surgical intervention is considered.

1. Keratoplasty (Corneal Transplantation):

Keratoplasty is a treatment used in advanced stages of keratoconus. When the corneal tissue has sustained extensive damage, corneal transplantation may be required. The procedure involves removing the damaged cornea and replacing it with a healthy donor cornea. In patients with severe visual impairment, keratoplasty can produce a significant improvement in vision.

Penetrating Keratoplasty: The full thickness of the corneal tissue is replaced.

Lamellar Keratoplasty: Only the outer layers of the cornea are replaced.

2. Femtosecond Laser-Assisted Keratoplasty:

Corneal transplantation can now be performed with laser assistance. Femtosecond laser technology enables more precise incisions during the procedure, which accelerates the recovery process and contributes to more successful outcomes.

Recovery Process:

Recovery following corneal transplantation can be lengthy. Vision improvement takes time; however, when the treatment is successful, patients experience a meaningful gain in visual quality.

The most appropriate treatment is determined by your ophthalmologist based on the stage of keratoconus, corneal thickness, and your individual visual requirements. Regular follow-up examinations and early diagnosis are essential in preventing vision loss.

Quality of Life After Keratoconus Treatment

Living with keratoconus can be challenging, particularly in advanced stages. Daily activities — reading, working at a computer, driving — can be significantly affected by the visual disturbances the condition causes. Quality of Life After Treatment:

 

1. Improvement in Visual Quality

Most patients achieve clearer, sharper vision following treatment. Options such as spectacles, contact lenses, or corneal collagen cross-linking (CXL) can improve visual function and make everyday tasks more comfortable.

Intracorneal ring segments can also enhance visual quality, particularly in patients with moderate-stage keratoconus.


2. Fewer Visual Limitations

As treatment reduces corneal irregularities, patients find it easier to carry out daily activities. Tasks such as driving, reading, and working at a computer become noticeably more manageable.

Improvements in night vision quality, in particular, help patients see more comfortably when driving after dark or in low-light environments.

 

3. Long-Term Effects on Health and Quality of Life

For most patients, halting the progression of the disease after treatment leads to a lasting improvement. This helps preserve quality of daily life without the need for continuous monitoring of disease progression.

 

4. Psychological and Social Effects

Patients who have experienced anxiety about their vision often feel more confident and socially engaged after treatment. Improved visual function supports greater participation in both professional and social life.

Enhanced visual quality may also contribute to a reduction in levels of depression and anxiety.

In summary, it is possible to maintain good visual quality after keratoconus treatment through regular follow-up examinations. Because every patient's situation is different, treatment options and post-treatment quality of life may vary depending on individual factors.

Why Assoc. Prof. Dr. Efekan Coşkunseven?

With an experienced specialist team, advanced diagnostic technology, and a patient-centered approach, the clinic offers reliable and effective solutions for high myopia. We develop the most appropriate treatment plan for each patient individually, with the goal of protecting eye health and improving quality of life.

Advantages of choosing Assoc. Prof. Dr. Efekan Coşkunseven:

  • Specialist Expertise: Physicians with extensive experience in treating high myopia.

  • Advanced Technology: Safe, efficient treatments performed with state-of-the-art equipment.

  • Personalized Care: Treatment options tailored to each patient's individual needs.

Patient-Centered Service: Meticulously managed treatment processes designed to achieve the highest level of patient satisfaction.

Frequently Asked Questions

1Keratoconus: An Overview
Keratoconus is a condition in which the cornea — the transparent front surface of the eye — progressively thins and bulges outward into a cone-like shape. This forward protrusion can cause significant vision loss that cannot be fully corrected with glasses. Keratoconus typically affects both eyes, though one eye is often more severely affected than the other.
2How do patients with keratoconus see the world?
Patients with keratoconus may experience double or blurred vision. They may also notice shadowing in their visual field, difficulty with night vision, or problems with light scattering.
3What are the risk factors for keratoconus?
Certain genetically inherited conditions, such as Down syndrome, Osteogenesis Imperfecta, and Marfan syndrome. Seasonal allergic conjunctivitis (hay fever) during childhood, along with habitual eye rubbing, can act as a trigger for keratoconus in individuals with a susceptible corneal structure. The use of ill-fitting contact lenses can cause degenerative changes in the cornea and may trigger the condition. Congenital ocular anomalies, Prolonged, unprotected lifetime exposure to UV radiation, Reduced collagen levels in the cornea, Night blindness (nyctalopia), Chronic ocular irritation, are among the recognized risk factors for keratoconus.
4Keratoconus: At What Age Does It Appear?
The exact causes of keratoconus are not fully understood, but genetic predisposition and mechanical eye trauma — such as eye rubbing due to allergies — play the most significant roles. For children with a family history of keratoconus, more frequent eye examinations are particularly important: where necessary, tests such as corneal topography can detect subclinical keratoconus early, allowing timely intervention to prevent disease progression. Keratoconus is a progressive condition. It typically begins during adolescence and continues to advance until around the age of 35, after which progression generally stabilizes.
5How is keratoconus diagnosed?
Keratoconus is diagnosed through comprehensive eye examinations and advanced imaging techniques. Your eye doctor will begin with a standard examination assessing visual acuity, astigmatism, and other refractive irregularities. This is followed by corneal topography, pachymetry, and ophthalmoscopic evaluation to analyze corneal thinning, cone-shaped protrusion, and irregular surface characteristics in detail.
6What are the symptoms of keratoconus?
As the cornea progressively bulges forward, myopia and astigmatism typically develop during adolescence, causing a gradual decline in vision. In the early stages of the disease, vision can still be corrected with glasses — though prescriptions change with increasing frequency. As the condition advances, however, high degrees of myopia and astigmatism develop that can no longer be adequately corrected with glasses. Patients often find themselves needing new glasses frequently, yet still unable to see clearly despite wearing them. Alongside these visual symptoms, eye allergies, itching, and light sensitivity are commonly observed. Once glasses are no longer sufficient, specially designed soft contact lenses for keratoconus — or rigid gas-permeable contact lenses — may be used to improve vision. If the disease is left unmonitored and untreated, the cornea can become severely thin, cloudy, and swollen, leading to a significant reduction in vision. At this advanced stage, keratoplasty (corneal transplantation) becomes necessary.
7What should keratoconus patients pay attention to?
People with keratoconus should avoid rubbing their eyes and attend regular eye examinations. In addition, wearing protective sunglasses against sunlight is also important.
8What are the treatment options for keratoconus?
In the early and mild stages of keratoconus, glasses and soft contact lenses are sufficient to improve vision. As the disease progresses, however, the cornea thins and distorts significantly — at this stage, glasses and soft contact lenses are no longer adequate. The following treatment options are used in keratoconus: Corneal collagen cross-linking (CXL) Specialty soft contact lenses Rigid gas-permeable contact lenses Piggyback lens system (rigid gas-permeable lens worn over a soft contact lens) Hybrid contact lenses Scleral or semi-scleral lenses Intracorneal ring segments (Intacs) Corneal transplantation (keratoplasty)
9What is the goal of keratoconus treatment?
Eliminating the disease entirely is not possible. The goal is to correct vision loss and halt the progression of the condition.
10Can every patient use a lens?
According to research, only 20% of the Turkish population can wear contact lenses; the remaining 80% are unable to tolerate them. Patients who cannot wear contact lenses are referred for surgical treatment.
11Is ring segment treatment safe and effective?
When ring segment treatment is performed correctly — with laser-assisted channel creation — it achieves high success rates. Suboptimal outcomes can occur with improper technique, which is why the procedure should be performed by an experienced surgeon.
12How can keratoconus be prevented in children?
Early diagnosis, keeping allergy and itching under control, and regular follow-up can prevent the disease from progressing. This way, children can be protected without the need for other treatments.
13What happens if keratoconus is left untreated?
When left untreated or without timely intervention, keratoconus can progress and lead to a significant reduction in visual acuity; however, appropriate contact lens use and other treatment options can keep its progression under control.
14Which specialists perform keratoconus treatment?
Istanbul stands out for its advanced eye care centers, offering experienced physicians and modern technology for keratoconus treatment. Assoc. Prof. Dr. Efekan Coşkunseven is among the leading figures in this field, recognized internationally for his expertise and contemporary approach to treatment.
15What is hybrid keratoconus treatment?
Hybrid treatment involves applying multiple therapies simultaneously or in stages — both to halt the progression of keratoconus and to improve visual quality. Rather than relying on a single method, a combined approach is tailored to the individual structure of your cornea.
16What is the recovery process like after keratoconus surgery?
- Some burning, stinging, and blurred vision in the first few days after cross-linking is normal. - Some fluctuation in vision during the first few weeks following intracorneal ring segment surgery is to be expected. - Recovery after keratoplasty takes longer (potentially several months) and requires regular follow-up examinations.
17What happens if keratoconus progresses?
As the disease progresses, the cornea continues to thin and the distortion worsens. This can lead to blurred and shadowed vision, light scattering, deteriorating night vision, and — in advanced stages — corneal scarring or rupture. In some severe cases, corneal transplantation may be necessary.
18What should you watch for after cross-linking surgery?
For the first 3 days, avoid touching or rubbing your eye. Use the prescribed drops as directed, keep water away from your eye, and wear sunglasses. For one week, avoid swimming pools and the sea, eye makeup, and contact lens use. Light sensitivity and blurred vision are normal in the first few days. Do not miss your follow-up appointments.
19Does keratoconus cause scratches on the eye?
No. LASIK and similar laser refractive procedures are not suitable for patients with keratoconus. These types of surgeries can further weaken the cornea and may accelerate the progression of the disease.

Turkey's Leading
Ophthalmology Specialist

Eye health is one of the most important factors directly affecting our quality of life. Prof. Dr. Efekan Coşkunseven is one of Turkey's leading ophthalmologists, with more than 20 years of experience in keratoconus, corneal diseases, laser eye surgery, and cataract treatment — having successfully treated thousands of patients throughout his career.

For More Information, Please Get in Touch

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