1. Corneal Iron Ring After Hyperopic LASIK
Grand Rounds April 2005
Jay C. Bradley, MD
David L. McCartney, MD

2. Report of Case: 56 year old male Pre-operative refraction
+6.00 –2.50 x 7
+6.00 –1.75 x 165
Pre-operative pachymetry
OD – 516 μm
OS – 525 μm

3. Operative Summary (2001): LADARVision 4000
Laser-assisted in situ keratomileusis
Blend Radius mm
Zone Size mm
Ablation depth OD – 91.0 microns
OS – 90.8 microns
No flap or ablation complications

4. Follow-up (2004)
Returns to clinic with complaints of decreased near vision OU
Does not use distance Rx
Normal exam except for trace NSC OU and prominent corneal iron ring OU (~ 5 mm diameter)
Patient given Rx for reading glasses

5. Corneal Iron Ring Photo

6. Prior Reports of Corneal Iron Ring After Hyperopic LASIK
Ozdamar A et al. Cornea Mar; 18(2):243-5.
3 patients with pre-op spherical equivalent refraction of to +6.50
Paracentral iron ring OU at 6 – 7 months after surgery
Localized to outside border of central steep zone
No change in ring at 1 year follow-up

7. Prior Reports of Corneal Iron Ring After Hyperopic LASIK
Probst LE et al. JCRS May; 25:
1 patient with pre-op Rx of –1.50 x 153 OD and –1.50 x 165 OS
Paracentral corneal iron ring OU at 6 months after surgery (5 mm diameter)
6.0 mm optical zone with 9.5 mm blend zone
Ring corresponded to base of hyperopic ablation on corneal topography
Increased mean pre-operative SE and ablation depth associated with deposition

8. Histology Hemosiderin deposition in basal corneal epithelial cells
Iron deposits when there is an abrupt change in corneal surface curvature in area of diminished tear flow and hydrodynamic stasis
(Hyperopic PRK)

9. Pathogenesis: Tear-pool hypothesis
Proposed by Gass (1964)
Sequestered iron in the tear film is preferentially deposited in areas of the cornea with pooling of the tear film
Explains Hudson-Stahli lines corresponding to the lid position at rest
Low [iron] in tears, protective effect of mucus, and occurrence of iron lines in eyes without tears question this theory

10. Pathogenesis: Basal-Cell-Migration Theory
Proposed by Rose and Lavin (1987)
Abrasive lid action on corneal surface induces enhanced mitotic activity
Dividing, nonmigrating, basal cells become mature and accumulate iron

11. Pathogenesis: Tear Desiccation Hypothesis
Proposed by Assil (1993)
Iron deposits occur in areas of initial tear breakup

12. Pathogenesis: Senescent Basal Cell Hypothesis
Proposed by Assil (1993)
Iron accumulates in the epithelial cells where there are diminished rates of cell turnover

13. Iron Lines Associated with Rx / Tx Corneal Procedures
Arcuate along anterior suture border after PK
Lamellar keratoplasty
Ring adjacent to margin of donor lenticule after epikeratophakia
Central stellate pattern after RK (~ 80 %)
Inferior line or midperipheral arcuate after intrastromal corneal ring segment (ICRS) placement
Central line after uneventful PRK (myopic and hyperopic)
Small central ring associated with steep central islands after PRK
Myopic and hyperopic LASIK
Overnight orthokeratology
Conductive keratoplasty

16. Iron ring associated with overnight ortho-K

18. Other Corneal Iron Lines
Fleischer ring
Associated with keratoconus
First reported in 1906
Partial or complete ring encircling base of cone
Yellowish to dark brown
Best seen with cobalt blue light

19. Other Corneal Iron Lines
Hudson-Stähli
Iron line along lower third of cornea in otherwise normal eyes
Associated with age
Area of tear pooling when eye lids at rest

20. Other Corneal Iron Lines
Stocker-Busacca line
Associated with pterygia
Anterior to leading edge
Yellow to golden brown

21. Other Corneal Iron Lines
Ferry’s line
Associated with filtering blebs
First reported in 1968

22. Other Corneal Iron Lines
Elevated corneal scars
Salzmann’s nodular degeneration
Corneal foreign body
Coats’ white ring
Juvenile corneal arcus lipoides

23. Coat’s White Ring

24. Salzmann’s Nodular Degeneration

25. Importance of Corneal Iron Lines
Diagnosis of associated ocular condition
Identification of corneal donor tissue with prior refractive surgery (ie LASIK flap)
Possible estimation of optical size and centration of ablation with hyperopic LASIK

26. Any Questions?