Experience of using myorings for correction of high myopia in patients with thin cornea
I.L. KULIKOVA, L.I. VASILYEVA
Cheboksary Branch of S. Fyodorov Eye Microsurgery Federal State Institution, 10 Traktorostroiteley Pr., Cheboksary, Russian Federation, 428028
Kulikova I.L. ― D. Med. Sc., Deputy Director for Clinical Work, tel. (8352) 36-91-53, е-mail: koulikova@mail.ru
Vasilyeva L.I. ― ophthalmologist, tel. (8352) 36-90-74, e-mail: liana.unishkova@mail.ru
The article presents the clinical functional analysis of the results of MyoRing implantation in patients with high myopia and thin cornea. 48 patients (86 eyes) aged 24-45 years were operated. Weak amblyopia and peripheral horioretinal dystrophy of retina was revealed in this group of patients. Before surgery, the mean spherical component of manifest refraction was -13.4±1.4 D, cylindric -2,5±1.2 D. Mean minimal pachimetry at the center was 464±20 mkm (range 430-498 mkm). Mean keratometry was 44.50±3.0 D (range 36.25-48.15 D). In four years after MyoRing implantation, UDVA was 0.45±0.6 D, CDVA 0.57±0,15D, spherical component was -0.7±0.31 D, cylindrical -0.3±0.15D. Corneal hysteresis (CH) was 9.43±0.01 mm Hg, cornea resistance factor (CRF) was 9.7±0.15 mm Hg. Keratotopographic indices were: ISV=72.05±16, IVA=0.89±0.14 mm, IHA=23.6±13.8 mkm and Rmin=7.7±0.15 mm. Besides high predictability of refractive effect and visual functions, the analysis showed the preservation of biomechanical indices of cornea and insignificant changes of keratotopographic indices in comparison with the norm, which confirms the safety and efficiency of MyoRing implantation in patients with high myopia and thin cornea.
Key words: high myopia, thin cornea, intrastromal corneal MyoRing implant, femtosecond laser.
REFERENCES
- Avetisov S.E. Modern approaches to the correction of refractive disorders. Vestnik oftal’mologii, 2006, no. 1, pp. 3-8 (in Russ.).
- Balashevich L.I. Refraktsionnaya khirurgiya [Refractive surgery]. Saint Petersburg: SPbMAPO, 2002. 285 p.
- Ambrosio R.J., Jardim D., Neeto M.V. Management of unsuccessful LASIK surgery. Comp. Ophthalmol. Update, 2007, vol. 8, pp. 125-141.
- Doga A.V., Kishkin Yu.I., Maychuk N.V. Korrektsiya «sverkhvysokoy» miopii metodom FemtoLASIK [Correction of «ultrahigh» myopia by the FemtolASIK method]. Sovremennye tekhnologii kataraktal’noy i refraktsionnoy khirurgii-2011: sb. nauch. st. Moscow, 2011. Pp. 227-231.
- Kulikova I.L., Pashtaev N.P. The first results of correction of ametropia with the use of femtosecond keratoma. Klinicheskaya oftal’mologiya, 2008, no. 3, pp. 87-90 (in Russ.).
- Aguilar V.L., Alonso M.L., Casanova I.J., et al. Intraocular pressure in myopic patients after Worst-Fechner anterior chamber phakic intraocular lens implantation. J. Refract. Surg, 2003, vol. 19, pp. 131-136.
- Barraquer J.I. Modification of refraction by means of intracorneal inclusion. Int. Ophthlmol. Clin, 1966, no. 6, rr. 53-78.
- Daxer A., Alio L., Pinero P. Clinical outcomes after complete ring implantation in corneal ectasia sing the femtosecond technology. Ophthlmology, 2011, vol. 118, no. 7, pp. 1282-1290.
- Kachalina G.F., Kishkin Yu.I., Maychuk N.V. Posleoperatsionnaya ektaziya rogovitsy: mify i real’nost’ [Postoperative ectasia of the cornea: myths and reality]. Sovremennye tekhnologii kataraktal’noy i refraktsionnoy khirurgii-2010: mezhdunar. nauch.-prakt. konf. 9-ya: materialy. Moscow, 2010. P. 398.
- Donald R.S. Actual and theoretical risks for visual loss following use of the implantable contact lens for moderate to high myopia. J. Refract. Surg, 2003, vol. 29, no. 7, pp. 1323-1332.
- Colin J. Current surgical options for keratoconus. J. Cataract. Refract. Surg, 2003, vol. 29, no. 2, pp. 379-386.
- Fraizl P., Daxer A. Structural transformation of collagen fibrils in corneal stroma during drying: an x-ray scattering study. J. Biophys, 1993, vol. 64, no. 4, pp. 1210-1214.