Corneal crosslinking for the treatment of keratoconus: results in

the initial 50 cases

Pierre Fournié, Jean-Louis Arné, François Malecaze

Purpan Hospital, Toulouse, France

The authors acknowledge no financial interest

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Treatment Procedure

1. Topography: 1. Topography: progressive type of progressive type of keratoconuskeratoconus >1D in 6-12 >1D in 6-12 monthsmonths >2D in 12-24 >2D in 12-24 monthsmonths2. Pachymetry: 2. Pachymetry: Corneal thickness Corneal thickness > 400 > 400 mm

3. Partial 3. Partial epithelium epithelium removalremoval8-9 mm8-9 mm

4. Apply 4. Apply Riboflavin: 1 Riboflavin: 1 drop every drop every minute for 20 minute for 20 minmin

5. Slit lamp 5. Slit lamp inspection inspection (blue light)(blue light)““yellow flare”yellow flare”

6. UVA (370nm)6. UVA (370nm)3 mW/cm3 mW/cm22

1 drop of 1 drop of Riboflavin every Riboflavin every 2 min for 30 2 min for 30 minmin

Preoperative Data

Treated eye (CXL) Contralateral eye

number 53 eyes (of 53 patients)

age 24.74±7.92 (range 17 to 40)

6M follow-up 53

12M follow-up 36

24M follow-up 15

BSCVA (decimal) 0.53±0.25 (0.1 to 1) 0.79±0.27 (0.1 to 1)

Kmax (D) 53.42±5.4 (43.49 to 66.1)

48.76±5.1 (41.85 to 65.8)

Cylinder (D) 5.28±2.76 3.67±2.73

Pachymetry () 482±59 471±62

Maximum K values (Kmax)

46474849505152535455

preopn=53

M1n=53

M3n=53

M6n=53

M12n=36

M24n=15

diopters

CXLcontra

p<.05

PreopPreop Post CXL 1 yearPost CXL 1 year Differential mapDifferential map

6 months (n=53) 1 year (n=36)

"Stabilization" Kmax (±1D)

66% (n=35) 61.1% (n=22)

"Regression" Kmax (<1D)

24.5% (n=13) 30.5% (n=11)

"Progression" Kmax (>1D)

9.5% (n=5) 8.4% (n=3)

BSCVA (Decimal)

00,10,20,30,40,50,60,70,80,9

1

preopn=53

M1n=53

M3n=53

M6n=53

M12n=36

M24n=15

CXLcontra

p<.05

05

101520

2530

3540

-3 -2 -1 0 1 2 3 4

lines of visual acuity

% of eyes

34%

sta

bili

zati

on

41% improvement

++ ++

6 months

Cylinder

0

1

2

3

4

5

6

7

preopn=53

M1n=53

M3n=53

M6n=53

M12n=36

M24n=15

diopters

CXLcontra

Pachymetry

420

430

440

450

460

470

480

490

500

preopn=53

M1n=53

M3n=53

M6n=53

M12n=36

M24n=15

CXLcontra

Endothelial Cell Count

2200

2300

2400

2500

2600

2700

2800

2900

preopn=53

M1n=53

M3n=53

M6n=53

M12n=36

M24n=15

CXLcontra

Ocular Response Analyzer

0123456789

preopn=53

M1n=53

M3n=53

M6n=53

M12n=36

M24n=15

CRFCH

p>.05

Conclusions

• In vitro studies show that riboflavin and UVA significantly stiffen the anterior 200-300 m of the cornea

• In our series, Riboflavin/UVA collagen crosslinking appears to be an efficacious procedure in inhibiting the progression of irregular astigmatism due to keratoconus while– stabilizing (±1D in 61.1%) or reducing (at least 1D in 30.5%) the

corneal curvature– and increasing BSCVA (at least 1 line in 41% of eyes)

• ORA failed to demonstrate any statistically significant difference after CXL