KeraRings - New clinical pathways in keratoconus

Dan GoreBruce Allan

At diagnosis…

Refractive correction pIOLFine shape correction PRK(≥2 years post CXL)

Gross shape correction ICRS (CDVA <20/20, coma >3µm)

CDVA poor (rigid contact lens dependent)

CDVA good(spectacle dependent)

Shape stabilisation CXL

UDVA good(spectacle independent)

Gore DM, Shortt AJ, Allan BD Eye 2013;27:329-39

KeraRing patients

• 17 eyes of 17 patients• Femtosecond laser channels• 16 keratoconus, 1 post-LASIK ectasia– Age 32 (range 25-47)– Refractive astigmatism 7.88D– UDVA < 20/200– CDVA 20/40

• Follow-up 20 months (range 14-25)

20/1200

20/600

20/480

20/400

20/360

20/200

20/12020/40

20/300

1

2

Uncorrected distance VA (n=10)N

umbe

r of e

yes

20/12020/80

20/6020/40

20/30 20/20

0

4

8

12 Corrected distance VAPre-opPost-op

Num

ber o

f eye

s

p=0.018

p<.001

Change in visual acuity

Coma: Pre-op -4.20µm Post-op -2.75µm (p<.001)

No change

Gain 1 line

Gain 2 lines

Gain 3 line

Gain 4 lines

Gain 5 lines

Gain > 5 lines

0

2

4

6

8

10

12

CDVA

UDVA

Num

ber o

f eye

s

<1

1.01 - 2.00

2.01 - 3.00

3.01 - 4.00

4.01 - 5.00

5.01 - 6.00

6.01 - 7.00

7.01 - 8.00

8.01 - 9.00

9.01 - 10.00

>100

2

4

6

Refractive astigmatismPre-opPost-op

Num

ber o

f eye

s

-8 -6 -4 -2 0 2 4 6

-14

-10

-6

-2

2

6Δ spherical equivalent

Post-op (D)

Pre-

op (D

)

-7.88-4.18

p <.001

Pre -3.62DPost -1.85D

0 2 4 6 80

2

4

6

8Corneal astigmatism (K2-K1)

Pre-op corneal astigmastim (D)Post

-op

corn

eal a

stigm

a-tis

m (D

)

-10-8-6-4-202468 Δ Kmax

Kera

tom

etry

(D)

KmeanPre 49.8DPost 48.6D

• Previously RGP intolerant• Now comfortable in toric SCL• PK/DALK avoided

-1.00/-4.25 x 60 CDVA 20/120

6.00/ -2.00 x 130 CDVA 20/20

Post-op Pre-op

Summary outcomes

• 4 patients progressed = CXL

• 16/18 (89%) pleased with outcome– Central striae, CDVA 6/9, elective DALK– CDVA 20/20 pre & post, cylinder reduced by 6D– 5 patients in toric SCLs previously intolerant of RGPs