Case One

Case History

• 5 y/o female
   
• History of trauma (fingernail) in right eye
   
• Followed by Herpes Simplex Viral infection OD
   
• Meds: Oral acyclovir syrup
   
• No topical medications
   
• Referred by pediatric ophthalmologist for CL fitting

K's and Rx

• OD 45.25 @ 018, 48.12 @ 108
   
• MR: OD +3.50 -3.00 X 020 20/25
          OS -0.25 -0.75 X 083 20/20

Subjective Symptoms

• Glare, halos, monocular diplopia OD
   
• Told no glasses could help
   
• Sees pediatric MDs for occasional flare-ups

Objective Findings?

A. Oblate cornea.

B. Spherical cornea.

C. Induced irregular astigmatism.

D. Induced regular astigmatism.

E. C and D

Assessment

• HSV scarring can result in any form of corneal irregularity
   
• HSV scarring can be epithelial or deep stromal
   
• Superficial scarring/contracture often = high astigmatism
   
• Deep stromal scarring = haze and irregular astigmatism
   
• Isolated peripheral scarring is also possible resulting in focal irregularity
   
• GP lenses create a new smooth optical surface; FL pooling always reveals areas of irregularity

Plan

• Fit our pediatric patient in a GP lens OD to correct anisometropia and irregular astigmatism
   
• Needs a bitoric because of high and relatively regular astigmatism confirmed by topography

Lens Order

• 7.08/7.56 9.5/7.6 -1.50/+1.50
   
• Boston EO, Bitoric Lenticular

 
 
 
Case Two

Case History

• 38 y/o male had RK surgery OU 15 years ago
   
• Has no spectacles, told no spectacles would reasonably correct his vision
   
• Had RK because had frequent and recurrent GPC with soft lenses
   
• Has seen two ophthalmologists in last year, only recommended treatment was pilocarpine drops used prn for improved vision
   
• Last ophthalmologist referred to me for a GP evaluation

K's and Rx

• Uncorrected VA OD 20/50, OS 20/40
   
• OD: 35.50 @ 170/37.50 @ 080
   
• OS: 35.62 @ 164/37.37 @ 074
   
• MR: OD +3.00 -1.50 X 135 20/60
          OS +1.50 -1.75 X 005 20/50

Initial Attempted GP Fit

• Boston ES OU
   
• OD 8.40 9.6/7.0 -6.25
  OS 8.20 9.6/7.0 -6.50
   
• OU Peripheral curves: 7.9/.7   9.5/.3   12.5/.3 reverse geometry design
   
• GP VA OD 20/25+, OS 20/30

Subjective Symptoms

• Improved vision but with halos, glare, occasional monocular diplopia OS
   
• Excessive itching
   
• Significantly worse VA X 30-60 minutes after lens removal

Objective Findings: What is the problem?

• flat fit
   
• steep fit
   
• diameter too small
   
• lens adherence

Assessment

• GP decentration on oblate irregular corneal surface
   
• GP follows steepest hemi-meridian, reverse geometry peripheral curves impinge into patient's optical zone distorting cornea
   
• Excessive central pooling traps bubbles and results in dimple veils
   
• Early GPC - mechanical irritation of thick edge design

Plan Corrective Action

• Flatten lens base curve to improve centration and decrease bubble entrapment
   
• Increase lens OAD and OZD to improve centration
   
• Keep same reverse geometry peripheral curves
   
• Improved centration will decrease corneal distortion in clear corneal zone
   
• Order plus carrier lenticular to decrease edge thickness
   
• Add Crolom drops QID OU

Reorder OS GP

• 8.40 10.2/7.4 -5.50
   
• periphery: 7.9/.8   9.5/.3   12.5/.3

Results

• VA 20/25+2, no itching, mild spectacle blur remains

 
 
 
Case Three

This case is fraught with several controversial LASIK issues, none of which will necessarily be discussed here. The two main controversies are treatment of amblyopic patients (even shallow amblyopes such as in this case) with refractive surgery and the treatment of diffuse lamellar keratitis (DLK). However, the LASIK outcome does present a unique contact lens fitting experience as you will see...

Background Information

• 28 y/o WF
   
• PMHx clear
   
• POHx: Strabismus surgery OS as child, worn SCls > 10 years, last X 15 days ago
   
• Meds: OCP
   
• Allergies: +Sulfa
   
• VA (cc)
  • OD: 20/30 (PH 20/20)
  • OS: 20/30 (PH 20/20)
     
• MRx:
  • OD: -3.50-0.25X090 (20/20+)
  • OS: -3.00-0.75X045 (20/25+)
     
• SLE/Entrance Testing:
  • Left hypotropia
  • Otherwise normal
     
• DFE:
  • WNL OD, OS
     
• Impression/Plan:
  • Strabismus and shallow amblyopia OS
  • Proceed with LASIK OS 1st

Initial Surgery

• OS Tx: 8/98
   
• Tx: -2.90 DS
   
• F/U X 3 wks:
  • UCVA: 20/30+ (pre-op BVA 20/25+)
  • MRx: +0.25-0.50X040 (20/25)
     
• Impression/Plan:
  • Proceed to OD 4 days later

LASIK Tx. OD

• POD #1 OD: F/U at referring eye care provider office, told cornea clear, f/u X 1 wk
   
• POD #2: Reports to MEEI with c/o haze/blur OD
   
• UCVA 20/80- (PH 20/25)
   
• SLE: 2+ DLK with minimal flap wrinkles centrally
   
• PF 1% Q1H, Ocuflox QID
   
• F/U 7 times over next 4 weeks
   
• Continued PF 1% X 4 wks with tapering schedule
   
• VA (sc) = 20/30 to 20/40 (PHNI)
   
• Topography: At week 3 shows area of flattening corresponding to previous area of inflammation

Tangential and axial view of the right eye (both images are of OD):

These topographies are 18 months post-resolution of the DLK noted in this case (taken at subsequent follow-up).

• SLE: At 3 weeks, obvious stromal melting noted in central area, essentially bisecting pupil approximately 10% of corneal diameter, 50% of pupil diameter with slit lamp beam.
   
• 4 weeks s/p LASIK OD:
  • UCVA = 20/30 (PHNI)
  • Pt. c/o glare, shadows, blur
  • MRx:
    • +0.50-0.75X045 (20/30)
      or
    • +7.00-0.50X030 (20/30)
       

Either manifest refraction performed on the right eye would yield the same BSCVA endpoint. With retinoscopy, two distinct reflexes were noted, depending upon whether light was shown through area within stromal melt or unaffected, surrounding cornea.

Impression/Plan:

• S/p LASIK with DLK, stromal melting.
• Refer to CL service for GP fitting

How Would You Proceed from Here?

The patient’s main complaints were overall decrease in image quality OD and significant glare/halo OD. My first thought was to trial a conventional GP given that initial refractive error was approx. –3.00 and therefore the optic zone curvature change simply from laser ablation was not significant.

• Trialed several GPs (BC = 7.60, 7.80, 8.00, etc. with varying optic zone diameters) in both conventional and aspheric designs.
   
• Each lens fit produced a typical post-refractive surgery pattern of central pooling with minimal (although present) peripheral alignment.
   
• The problem, however, was bubble formation over the area of stromal melting (the area bisecting the pupil).
   
• Remember my manifest refraction above of +7.00-0.50X030 – significant flattening had occurred in the area of stromal melting leading to the two different refractions as well as the localized area of flattening noted with corneal topography.

Other Options?

Looking at the numeric scale on the topography above, there is (at a maximum) an approx. 4 to 4.5 D difference from the flattest curvature (localized over the area of stromal melt) to the curvature of the unaffected/untreated peripheral cornea. Given this 4 D change in curvature and the bubble formation present in conventional GPs, a reverse geometry lens was fit.

Final Parameters of RGL

• 8.44 BC
   
• 10.0 OAD
   
• 6.0 OZ
   
• 44.0 D Rev Curve (4 D rev. curve)
   
• +0.25 DS
   
• No c/o glare/ghost
   
• Good central and mid-peripheral alignment
   
• Pt. last seen 7/01 and has worn the same lens for the last 1.5 years (two lens changes total over last 3 years). A new lens was ordered and she continues to note glare/halos without her lens, 20/30 UCVA OD (although unhappy with quality of VA) but is overall doing well when the GP is worn.