“Central and Peripheral Corneal Iron Deposits after Implantation of the KAMRA™
(AcuFocus Corneal Inlay)“
G.Nix
1, O.Seyeddain
1, W.Riha
1, M.Hohensinn
1, G.Grabner
1, E. Messmer
2,
A.K.Dexl
11 University Eye Clinic, Paracelsus Medical University, Salzburg, Austria 2 Department of Ophthalmology, Ludwig-Maximilian-University, Munich,
Germany
Methods
We evaluated 32 eyes undergoing KAMRA™
implantation. The intracorneal inlay was implanted by one surgeon (G.G.) in the non-dominant eye by creating a superior hinged flap with the Intralase 60kHz femtosecond laser and placing it over the line of sight intrastromally.
Corneal iron deposits were analyzed with slit-lamp and in vivo confocal microscopy with regard to the postoperative time interval and corneal topography.
Purpose
To describe central and peripheral corneal iron deposits after KAMRA™ implantation in naturally emmetropic presbyopic patients.
Results
Seventeen (53%) of 32 eyes developed brown-colored corneal iron deposits of variable density in the epithelium. One had deposits in the center only (6.0%); eight at the periphery of the inlay (47.0%); and eight over both areas (47.0%). These are best observed in blue light. On confocal microscopy clusters of Iron deposits were located very near to Bowman´s membrane and single dots of iron deposits were found in the remaining part of the epithelium. The median interval between KAMRA™
implantation and the first diagnosis of corneal iron deposits was 22.2 months. Location of this iron deposits correlated positively with the characteristic albeit minimal changes of corneal topography after KAMRA™ implantation.
Conclusions:
This is the first report of the appearance of corneal iron deposits following KAMRA™
implantation in 17 patients. They have no noticeable influence on final visual acuity, either distance or near, corrected or uncorrected. As reported for other corneal iron lines and dots (e.g. the Hudson-Stähli-line, iron deposits with keratoconus, the Fleischer ring, following trabeculectomy, radial keratotomy, epikeratophakia, LASIK and others) the authors suggest that alterations in tear film thickness, possibly its composition and corneal epithelial basal cell storage - as a result of changes of corneal topography - constitute the contributory factor for these specific iron depositions.
S A L K
References:
1. Seyeddain O, Riha W, Hohensinn M, Nix G, Dexl AK, Grabner G. Refractive Surgical Correction of Presbyopia With the AcuFocus Small Aperture
Corneal Inlay: Two-Year Follow-Up;
J Cataract Refract Surg. 2010 Apr. 28: 1─ 9 (Epub ahead of print) 2. Hudson AC. A note on certain peculiar pigmentary markings in the
cornea. R Lond Ophthalmol Hosp Rep. 1911; 18: 198─ 202
3. Stähli J. Über den Fleischerschen Ring beim Keratokonus und eine neue typische Epithelpigmentation der normalen Kornea. Klin Monatsbl
Augenheilkd. 1918; 60: 721─ 741
4. Fleischer B. Über Keratokonus und eigenartige Pigmentbildung in der Kornea. Münch Med Wochenschr. 1906; 53: 625─ 626
5. Steinberg EB, Wilson LA, Waring GO III, et al. Stellate iron lines in the corneal epithelium after radial keratotomy. Am J Ophthalmol. 1984;
98: 416─ 421
6. Grabner G. Eine neue zentrale, epitheliale Eisenablagerung nach
Epikeratophakie bei höhergradiger Myopie. Klin Monatsbl Augenheilkd 1987; 190: 424 ─ 427
7. Ruckhofer J. Klinische und histologische Studien zu den intrastromalen kornealen Ringsegmenten (ICRS®, Intacs®). Klin Monatsbl Augenheilkd.
2002; 219: 557─ 574
8. Yeung L, et al. Central Corneal Iron Deposition After Myopic Laser- Assisted In Situ Keratomileusis. Cornea 2006; 25(3): 291─ 295
9. Fernandes BF, et al. Histopathological study of 49 cases of keratoconus.
Pathology 2008; 40(6): 623─ 626 Fig. 1: HRT II with Rostock Cornea Module
Fig. 3: Iron deposits 24 month after implantation and corresponding corneal topography
Fig. 4: Central and peripheral iron deposits 24 month after implantation
Fig. 5: Central and peripheral iron deposits 18 month after implantation
Fig. 2: Confocal image: Iron deposits in Epithelium
Author Disclosure Block:
G.Nix (F), W.Riha (F), M.Hohensinn (F), O.Seyeddain (F), A.Dexl (F) and G.Grabner (F).
Clinical Study Payments by Acufocus Inc., Irvine, California
