What is Keratoconus?

Keratoconus

Introduction 3

An ophthalmic condition that is characterized by progressive distortion of the corneal surface. This condition is non-infectious, noninflammatory, and involves both corneas. This ectatic condition manifests with a cone-like protrusion of the cornea with an irregular surface. The light passes and reflects through the cornea just like a mirror and if the surface is irregular then the image will be distorted. Therefore, the patients usually experience decreased visual acuity, image distortion, and photosensitivity. 

Unlike other visual problems, keratoconus cannot always be corrected with usual spectacles. Keratoconus typically occurs at puberty and may progress after 30 years of age. Most of the patients may remain asymptomatic due to mild corneal distortion. Keratoconus is a progressive condition so visual problems may develop over time. Early diagnosis and treatments of keratoconus may prevent visual disturbances and loss of vision. 

What are the causes of keratoconus? 2

The exact cause of keratoconus is unknown but the following conditions may increase the chances of disease:

• Wearing rigid contact lenses

• Rubbing of eyes (chronic)

• Atopic/allergic disease

• Connective tissue disorders

• Down syndrome 

• Family history of keratoconus 

What Are The Signs And Symptoms Of Keratoconus?

Keratoconus may remain asymptomatic for extended periods. This condition is bilateral but may be asymmetric. If visual distortion or blurriness is noticed, glasses may or may not help.  A patient of keratoconus may present with the following signs and symptoms depending upon the degree of corneal distortion:

• Blurring of vision 

• Formation of glares and halos around light

• Seeing ghost-like images

• Sensitivity to light 

• Decreased vision in low light conditions 

• Itchy eyes

• Headache

• Pain behind eyes

• Multiple failed attempts at spectacle correction

Severe keratoconus may be associated with:

• Increased corneal irregularity (checked by an ophthalmologist)

• Increase in severity of existing symptoms 

• Corneal scarring

How Is Keratoconus Diagnosed? 1

Unlike other eye diseases, keratoconus doesn’t require laboratory investigations. Diagnosis of keratoconus is made with the help of the following:

• History

• Slit lamp eye examination 

• Retinoscopy

• Corneal tomography

• Corneal topography

• Biomechanical devices

• Tear fluid level

What Is The Treatment Of Keratoconus? 1,2

The management of keratoconus depends on the stage of disease and progression. If keratoconus is not progressing then management aims to correct visual disturbances.  If keratoconus is progressing then treatment aims to stop the progression. If the disease is diagnosed at an early stage then minimally invasive treatment options can lead to good results. 

1. Custom contact lenses to fit a patient’s corneal surface may provide some control of the disease. 

2. For mild to moderate keratoconus, Rigid Gas Permeable contact lenses are used for visual improvement. The tear layer between the cornea and contact lens may negate the surface irregularities but these rigid contact lenses can be difficult to wear for longer durations. 

3. Corneal collagen cross-linking is an outpatient procedure that increases the corneal rigidity and slows the progression of keratoconus. Studies show that corneal collagen cross-linking decreases the need for future invasive treatments. 

4. Corneal collagen cross-linking can also be combined with laser ablation of the corneal surface to improve outcomes. This technique is being used outside of the USA. 

5. Intracorneal ring segments may be applied to flatten the corneal surface

6. If symptoms are severe and not resolved with treatments as mentioned above then a corneal transplant is the last resort.

Keratoconus is a progressive distortion of the corneal surface that can result in visual disturbances and even blindness. If diagnosed at an early stage then keratoconus has a good prognosis. If you’re facing any of the aforementioned signs or symptoms, contact your ophthalmologists for a full evaluation.

References 

1. NCBI - WWW Error Blocked Diagnostic. (n.d.). NCBI. Retrieved August 12, 2022, from https://www.ncbi.nlm.nih.gov/books/NBK470435/

2. Yeung, K. O. K. D. (2022, March 9). Keratoconus: Practice Essentials, Background, Pathophysiology. Medscape. Retrieved August 12, 2022, from https://emedicine.medscape.com/article/1194693-overview

3. What Is Keratoconus? (2022, March 25). American Academy of Ophthalmology. Retrieved August 12, 2022, from https://www.aao.org/eye-health/diseases/what-is-keratoconus

Author

Eye Surgeons Associates Drs. Zuhair H. Peracha, Manal H. Peracha-Riyaz, Eric Zuckerman, Matthew Pieters, and Leila Siblani are dedicated to excellence in eye care and service. We utilize the latest treatment methods and procedures, including routine eye care, cataract surgery, glaucoma treatment, retinal disease management, diabetic eye treatment, and eyelid surgery.