Video of the month | July 2024 | ICRS (Intracorneal Ring Segment) implantation in a case of moderate sag keratoconus – when less is more

Presented by: Miltos Balidis MD, PhD, FEBOphth, ICOphth

Edited by: Penelope Burle de Politis MD

Keratoconus is a form of corneal ectasia resulting from abnormal corneal biomechanics.  The irregularity in corneal curvature caused by keratoconus produces optic aberrations that can lower visual acuity and/or significantly compromise vision quality in the affected eyes.

The management of keratoconus includes a variety of conservative and interventional approaches that can be tailored according to the case. Risk factors, presence or absence of disease progression, severity grading, degree of visual impairment and impact in life quality, thinnest corneal pachymetry, corneal scarring due to hydrops, and even the shape and location of the steepest corneal zone, all must be considered while choosing the most suitable therapeutic strategy.

One of the treatment options for moderate asymmetric keratoconus – notably sag type – is the implantation of intracorneal ring segments (ICRS) in order to reduce corneal curvature irregularity, making it more fit for supplementary optical correction – either with glasses or contact lenses.

Intracorneal ring segments and ICRS implantation techniques have been perfected over the years, with progressively better outcomes for both best-corrected and uncorrected distance vision. Most of all, ICRS have helped reduce or at least postpone the need for corneal transplantation in keratoconic eyes.

In this video, recorded in the main operating room of the Ophthalmica Eye Institute, in Thessaloniki, Greece, Dr. Miltos Balidis, MD, PhD, FEBOphth, ICOphth performs an ICRS implantation on a patient with moderate keratoconus in his right eye. The patient was intolerant to contact lenses and BCVA with glasses was no better than 3/10 in that eye.

The surgical steps and timing in the video are as follows: Creation of the intrastromal tunnel with femtosecond laser (00:00 to 00:05). Identification and dissection of the superior entry (up until 00:32). Further tunnel dissection with the tunnel dissector spatula (up to 01:33). Insertion of a Keraring (Mediphacos) ring segment (02:30). Ensuring the correct placement of the ICRS with its entire length inside the tunnel (03:00). Antibiotic drops instillation (03:27).

“Sculpture is the art of the hole and the lump.” (Auguste Rodin)

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