It is a progressive corneal disease whose beginning signs can appear around the twenties and which causes a conical bulge of the cornea with the appearance of irregular astigmatism sometimes associated with myopia and causing poor visual quality with glasses.  

SEMI-RIGID CONTACT LENSES OR SCLERAL LENSES:
These are adaptable lenses in case of keratoconus to provide better visual quality than with glasses, these lenses can absorb corneal astigmatism. They are of the classic semi-rigid type or lenses specially designed for keratoconus and requiring personalized measurements, adaptation with regular monitoring. 

CORNEAL CROSS-LINKING:
It is a technique aimed at stiffening and freezing the cornea and stopping corneal bulging by ultraviolet treatment.Corneal Cross-Linking requires the application of riboflavin and ultraviolet light for a few minutes after mechanical or Excimer laser de-epithelialization of the cornea. This intervention can be carried out under topical anesthesia by drops.Postoperative discomfort or pain is present for 24 to 48 hours.In some cases, Corneal Cross-Linking is associated with a surface treatment by Excimer Laser guided by corneal topography (PRK or PTK): TOPOGuided treatment. 

INTRACORNEAL RINGS
- Delayed healing which may lead to blurred vision requiring anti-inflammatory treatment with resorption of the corneal disorder several weeks later.- Rare risk of infection (1/4000) requiring treatment with local antibiotic therapy. - 48-hour post-operative pain reduced by painkillers and a dressing lens. 

INTRACORNEAL RINGS
Intracorneal rings are PMMA rings inserted in the posterior third of the cornea to flatten the most arched part of the cornea suffering from keratoconus with irregular astigmatism.This surgical procedure is performed on an outpatient basis under topical anesthesia by drops and can be combined with Corneal Cross-Linking. It can reduce astigmatism and allow better visual function with glasses or contact lenses.

COMPLICATIONS OF INTRA-CORNEAL RINGS
- Moderate postoperative pain for 24 hours- Halos and glare by light due to rings. This is a rare complication requiring the removal of the intracorneal ring if these visual phenomena are very disturbing. - Displacement of the ring with sometimes corneal lesion. This complication is mainly due to friction which must be avoided after surgery. 

INTRACORNEAL RINGS (KERARING)
These are PMMA intracorneal rings placed at the level of the most arched cornea in order to reduce irregular asigmatism. Depending on the case, one or two rings are necessary.This surgical technique allows the flattening of the cornea and promotes better visual acuity and better tolerance to contact lenses. This surgical technique can be performed on an outpatient basis under topical anesthesia by drops. 

INTRAOCULAR IMPLANT OF THE PHAQUE:
ARTISAN ARTIFLEX VISIAN ICL and TORIC VISIAN ICL type intraocular phakic implants are placed for the correction of residual myopia and astigmatism, after stabilization of the keratoconus by Corneal Cross-Linking or by Keraring. 

CORNEAL TRANSPLANT:
Solution of last resort, in case of very advanced keratoconus or non-stabilization of keratoconus and failure of the adaptation of semi-rigid lenses, Cross-Linking and the possibility of placing intraocular implants.This involves replacing the cornea with a graft. This technique can be performed either by a lamellar graft or a full-thickness graft.The corneal transplant requires the placement of corneal sutures around the edge of the cornea. These stitches can only be removed one year after the operation.The induction of astigmatism and sometimes high myopia are possible, which can be corrected by Lasik or, if the values ​​are very high, by intraocular implants of the ARTISAN or ICL TORIC type.