Keratoconus eye disorder is also called KC. Recent advances in management have brought. renewed interest in helping patients who had no hope before. We need to understand the disorder to comprehend best strategy for halting its progression.
What is Keratoconus Eye Disorder?
In simple words Keratoconus eye disease is a defect in the clear part of the eye or the cornea. The cornea is made up of strands of protein called collagen fibrils. Cornea has three main functions. The first is to keep itself clear. It needs to allow the light to pass through without distortion. Cornea needs to converge the light so as to bring it to focus on the macula, In fact the convergence power s stronger than of the natural lens of the eye. It also needs to withstand the pressure of the fluidic internal contents of the eye. Finally, it acts as a protective barrier preventing physical, microbiological, chemical and radiation hazards from reaching deeper parts of the eye.
Gene abnormalities lead to abnormal expression of collagen proteins in the cornea, this makes the collagen less attached to each other. Its like having slippery noodles. When one tries to pile them they slide away. This abnormal cornea is not able to withstand the outward force exerted by the internal liquids of the eye. The fibers start slipping away to the periphery. This starts the bulging of the eye. Gravity now acts force on this weekend bulging cornea, pulling the cone down. The shape of the cornea is altered from a prolate to a cone. This leads to distortion of the incoming light. Instead of getting focused at one point it gets scattered. the information brought from the universe is therefore not transferred properly to the brain,
It is a degenerative disease affecting both eyes. It leads to progressive thinning and bulging of the cornea that results in blurred vision from irregular astigmatism visual loss in early adulthood. It has been the most common cause of corneal transplant in the developed world. The progression may be different in the two eyes. At presentation one eye may be more involved with keratoconus eye disorder than the other. This can lead to a mistaken impression that the disease is present only in one eye.
Symptoms of Keratoconus
Rubbing of the eye is a hallmark of Keratoconus eye disease. The same genetic factors which cause collagen abnormality also cause release of chemical which incite rubbing. These enzymes which weaken the cornea cause irritation leading to rubbing. As the fibers slide weird sensations received by rubbing may be produced. Rubbing also lifts the slippery fibers improving the vision temporarily. A research has even proposed that the disease can be halted by avoiding touching the eye.
Poor vision, headaches, glare, night vision problems will be discussed in detail.
Spectrum of Keratoconus Eye Disorder
The keratoconus eye disorder may have different expression. Axial corneal thinning (apex cone), inferior corneal thinning (dropped cone, pellucid marginal degeneration), or generalized corneal thinning (keratoglobus). It is unclear as of 2017, whether these are variants of KC or distinct conditions. To complicate diagnosis certain eyes can be thin but may not have KC.
Structure and proteomics of Keratoconus Eye Disease
Let’s look at the cause of defects in keratoconus eye disorder in more detail. A theory suggests that epithelium may be abnormal releasing enzymes which degrade the collagen in deeper layers. On microscopy there are breaks in bowmans membrane and thinning of the collagen layers of the stroma of the cornea. Proteoglycans may be increased, decreased on normal. In eyes with keratoconus there is upregulation of decorin and keratocan. There are fewer keratan sulfate chains. The volume of collagen is less. There is altered distribution of collagen type III in scarred regions of KC tissue. Other than this the types of collagen is similar to normal eyes Examination of the tears or corneal tissues from patients with KC has identified differential expression of proteins, cytokines and enzymes compared with controls.
The genetic expression of abnormal proteins leading to a defective structure yields certain signs. An astute clinician can find scissored reflex on retinoscopy, tanning and bulging with haas striae on slit lamp examination. The definitive signs are picked up on corneal topography and pachymetry distribution map.
Stromal thinning, a hallmark of KC, is caused by a reduction in the number of lamellae of collagen I fibres within the affected region rather than compaction of collagen fibrils. has been attributed to collagen degradation by proteolytic enzymes or decreased levels of proteinase inhibitors, it has also been proposed that collagen is not lost but simply redistributed within the cornea by slippage between the lamellae X-ray diffraction studies support the redistribution proposal.
Large family studies and variability between Israel, Mexico and Russia point to a genetic influence. Genome-wide association studies (GWAS) identified a single-nucleotide polymorphism (SNP) within or nearby the following genes/loci; FOXO1, FNDC3B, RXRA-COL5A1, MPDZ-NF1B, COL5A1, and ZNF469.
All family members of keratoconus patients including siblings, parents and children should be screened for keratoconus eye disease. They should also be warned to chose epilasik procedure over lasik eye surgery.
Leber congenital amaurosis, anterior polar cataract, Brittle cornea syndrome, with a 10–300-fold higher prevalence in individuals with Down syndrome and with connective tissue disorders such as Ehlers Danlos syndrome. A thorough eye exam should be performed in al patients of KC to detect other abnormalities.
Living with keratoconus eye disorder can be a challenge. Most eye doctors do not understand the problems faced by people suffering from this corneal bulging disease. KC does not even spare the rich nor famous. Let these celebrities with Keratoocnus be an inspiration for achieving greater heights in your chosen profession.
If you are suffering from keratoconus learn about the latest advances in diagnosing and treatment of keratoconus. You may be able to halt the side effects plaguing your life – consult with a keratoconus surgeon.