Use Of Presbymax Reversal For Advanced Keratoconus Managment In Patients Using The Schwind Amaris

When dealing with advanced keratoconus patients who are not able to achieve CDVA of logMAR 0.2 or better when corneal tissue allows we attempt to use topography or ocular wavefront guided PRK/PTK to enhance the shape of the cornea before CXL to allow patients to use soft contact lenses or eye glasses and still achieve a good degree of visual acuity. Unfortunately when face with keratoconus grade 4 often times the anterior surface is either too distorted to be used to plan a treatment or there is not enough tissue for a classical approach to corneal ablation. We wanted to explore the use of presbyopia reversal option to modify the Q value of the cornea to attempt to increase best CDVA while using less tissue than standard guided options.

Svjetlost Eye Clinic, Zagreb, Croatia

We selected 7 eyes with advanced keratoconus and no viable classical topography or ocular wavefront guided options available due to thin corneas or inability to export the images after hydrops damage. The laser was set to the PresbyMAX reversal of monocular non-dominant eye for the eye we wanted to treat, with presby addition being selected between 1.5D and 3D depending on elevation above center point we wished to correct for. Surgery was performed with Amaris and immediately after followed by CXL. CXL was performed based on the new Sub400 protocol by Hafezi et al. due to most of the corneas being well below the usual 400 micron depth.

All 7 eyes treated with this option showed an improvement in CDVA, on average the CDVA in photopic conditions increased from 0.8 logMAR (range 1.3 to 0.5) to 0.3 logMAR (range 0.8 to 0.05). Mean follow up on these cases has been 8 months (range 3 to 12) but based on previous experiences with PRK and CXL we believe these patients will remain stable for a number of years. These patients were mostly recruited from our PKP list and this was an attempt to delay the PKP by doing a last ditch effort to enable some usable vision from their existing corneas. 

In cases where PKP is the only remaining option attempting to use PresbyMAX reversal to modify the Q value of the cornea of advanced keratoconus patients is a viable option that should be tried in an attempt to delay or avoid the PKP. This was originally meant to save a 14 year old boy with HM vision from PKP, today 1 year after the treament the young man has CDVA of logMAR 0.3 with a soft contact lens. We as doctors sometimes need to attempt odd-ball ideas to try and help our patients achieve more quality of vision and life.