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Keratoconus

Keratoconus is an eye disease that is usually seen in early adulthood and lasts ‎until the third decade of life. As a result of this disease, the normal shape of the ‎cornea with a rounded and spherical shape, becomes conical, protruding and ‎the patient's vision gradually decreased. Keratoconus is a progressive disease ‎that is occurred in one or both eyes but often is bilateral.‎

This protrusion is most often in the lower half of the cornea and initially ‎causes astigmatism. (Of course, not all cases of astigmatism are due to the ‎keratoconus.) In mild cases or in the early stages of keratoconus, visual acuity ‎can be partially corrected with glasses. As the disease progresses, vision is ‎improved only by the use of a hard contact lens and gradually, due to the ‎intolerance of the hard lens, surgical procedures such as intra-corneal looping ‎and finally corneal transplantation should be used.‎

In the past few years, a method has been used to slow the progression of the ‎disease called cross-linking surgery or corneal fixation.‎

To increase vision in cases that the glasses are not responsive, use a hard ‎contact lens, ring or cornea transplant.‎

  • Cross-linking surgery advantages
  • Description of the operation
  • Cross-linking surgery candidate
  • Complications
  • Keratoconus treatment for
    increasing patient's visual acuity
  • Keraring and INTACS rings
  • Myoring ring

Reducing the speed of keratoconus progression.‎

This operation done without anesthesia and it lasts about 40 minutes.

In this action the eye and surrounding area is first disinfected and the eye ‎surface becomes numb with using the drops. The patient will not feel pain ‎during surgery. The surgeon then removes the superficial corneal layer ‎‎(epithelium) using a surgical tool.‎

Riboflavin (Vitamin B2) is drip in the eye every 3 minutes for up to half an ‎hour. Finally, the eye is exposed to ultraviolet radiation. With the help of ‎riboflavin, this radiation creates transverse bonds between the strands and ‎layers of the collagen layer of the cornea, which ultimately increases corneal ‎stiffness. Finally, the surgery site is covered with a soft bandage lens and ‎Surgery ends.‎

‎1- Patients recently diagnosed with keratoconus.‎

‎2- Young and middle-aged people whose disease is progressive.‎

‎3- Also, those who contact lens do not fit well on their eyes.‎

‎4- The patient should have a definite diagnosis of keratoconus and documented ‎evidence of disease progression.‎

‎5- The corneal thickness should be at least 400 microns.‎

Risk of corneal infection may occur in any operation that sanitation is ‎essential.‎
‎1- Treatment with hard contact lenses
‎2- Surgery treatment

a) Ring insertion b) Corneal transplantation

Another surgical treatment of keratoconus is the insertion of a ring in the ‎corneal thickness.‎

The intra-corneal rings are divided into two groups, a piece (segmental) or ‎complete (currently myoring).‎

The most common segmental rings are Keraring and INTACS rings.‎

Description of the operation

After creating a tunnel in the corneal thickness that is created by a diamond-‎blade device or by a femto laser, the lens is inserted into the corneal thickness ‎and reduces the corneal curvature by extending it to the central part of the ‎cornea. So, irregularities corneal surface is reduced. These rings are made of ‎special plastic that is compatible with the cornea.‎

Advantages

‎1- By regularizing the corneal surface, corneal curvature curves to normal ‎resulting in improved visual acuity and contact lens tolerance.‎

‎2- The cornea stabilizes and delays or eliminates the need for corneal ‎transplantation.‎

‎3- For patients with mild to moderate keratoconus (KCN) have a clear cornea, ‎giving better vision with or without glasses.‎

‎4- The operation is performed with anesthesia and the patient does not need to ‎be anesthetized.‎

‎5- An alternative to corneal transplant for patients who do not have severe ‎keratoconus.‎

‎6- Reverse this action by removing the ring from the cornea.‎

‎7- Usually two rings are needed to correct the cornea.‎

Disadvantages

‎1- In some cases, the amount of correction is not as expected.‎

‎2- The possibility of gradual removal of the ring from the cornea, especially if ‎you rub the eye. (Intersection performed)‎

Complications

‎1- Infection

‎2- Inflammation

‎3- The deposition of calcium materials around the ring

The duration of the operation:‎ 1:15

Description of the operation

In this method, a pocket maker or femtosecond laser is made incision at 300 ‎microns from the surface of the cornea, and then the complete myoring ring is ‎inserted into the corneal thickness.‎

Myoring surgery advantages‎

‎1- For patients with moderate to severe keratoconus (KCN) have a clear ‎cornea, giving better vision with or without glasses.‎

‎2- The operation is performed with anesthesia and the patient does not need ‎to be anesthetized.‎

‎3- Replacement for hard contact lense or corneal transplant for patients who ‎have severe keratoconus.‎

Disadvantages‎

In some cases, the amount of correction is not as expected. However, almost ‎all patients see well than before surgery.‎

Complications‎

‎1- Infection

‎2- Inflammation

‎3- The deposition of calcium materials around the ring

NOTE: In cases that the corneal thickness is less than 380 microns due to ‎keratoconus, it is not possible to insert a ring.‎

The duration of the operation: ‎1:50‎

DNN