1. The Differences of Depth Parameters of Deposits Depending on the Morphology in Granular Corneal Dystrophy Type Ⅱ by Fourier Domain Optical Coherence Tomography Jin Pyo Hong,MD 1, Jae Lim Chung,MD 1, Jung Won Park,MD 2, Tae-im Kim,MD,PhD 1, Kyoung Yul Seo,MD,PhD 1, Eung Kweon Kim,MD,PhD 1 1 Corneal Dystrophy Research Institute, Department of Ophthalmology, College of Medicine, Yonsei University, Seoul, Korea 2 Daegu Yonsei Eye Clinic, Daegu, Korea Authors have no financial interest

2. Purpose Granular corneal dystrophy type Ⅱ (GCD Ⅱ )  Arg124His mutation in the Bigh-3 gene  Histologic feature of hyaline granules and amyloid lattice lines  Granular deposits as the earliest manifestation  Lattice deposits as later presentation  Diffuse haziness as getting older Surgical treatment of GCD Ⅱ  Phototherapeutic keratectomy(PTK)  Penetrating keratoplasty(PKP)  Lamellar keratoplasty(LKP) The depth of different deposits according to the patterns  Should be identified before surgery  Critical to decide which treatment modalities  Such as PTK, PKP, LKP

3. Purpose Fourier domain optical coherence tomography, RTVue- 100 ® (Optovue Inc, Fremont, CA)  High speed, high resolution tomography scanning  5 μm depth resolution  Layer by layer assessment  26,000 A scan/second  0.04 second of one B scan acquisition Purpose of this study  To evaluate the differences of depth parameters depending on morphology of deposits using Fourier domain optical coherence tomography, RTVue- 100 ®

4. Methods Patients  54 patients were evaluated  Heterozygous GCD Ⅱ by gene analysis  No history of uveitis, glaucoma, other ocular surface disease, previous operation Methods  Standardization of measuring CCT for RTVue-100® with ultrasonic pachymeter 20 normal subjects (40 eyes) 13 GDCII patients (23 eyes)  3 Classifications of deposits detected by RTVue-100® Granular, lattice, diffuse haziness  Recurrent deposit after refractive surgery  Two points for each different deposits per one patient

5. Methods Classification  Type I – diffuse haziness  Type II – granular deposits Type IIa – round granulated Type IIb – round spiculated  Type III – lattice deposits Type IIIa – spiculated lattice Type IIIb – conventional lattice (with long branches) Parameters  Following parameters measured from Bowman’s layer perpendicularily Distance of upper surface from Bowman’s layer(USBL) Distance of lower surface from Bowman’s layer(LSBL) Thickness of deposits(TD) LSBL TD USBL Bowman’s layer

6. Results Standardization of measuring CCT for RTVue-100 ® with ultrasonic pachymeter CCTRTVueUltra sonop Normal subjects (n=40) 526.3±26.7525.6±26.20.149 GCDII patients (n=23) 528.6±35.5522.5±35.10.295 p0.7230.655 Type I  diffuse haziness (white arrow)

7. Results Type IIa  Round granulated (white arrow) Type IIb  Round spiculated (white arrow)

8. Results Type IIIa  Spiculated lattice (white arrow) Type IIIb  Conventional lattice (white arrow)

9. Results Recurrent deposits after LASIK

10. Results The various parameters of deposits Diffuse haziness (n=58) Granular deposits (n=59) Lattice deposits (n=74) P USBL0065.4±48.0<0.001 LSBL47.7±10.291.3±39.5313.3±71.4<0.001 TD47.7±10.291.3±39.5246.2±71.9<0.001 The differences of depth between granular deposits (Type IIa vs Type IIb) Parameters of granular deposits P Round granulated (n=45)Round spiculated (n=14) USBL00- LSBL85.7±22.784.7±17.40.899 TD85.7±22.784.7±17.40.899

11. Results The differences of depth between two different shaped lattice trunks(Type IIIa vs Type IIIb) Parameters of lattice trunks P Spiculated lattice (n=14)Conventional lattice (n=45) USBL62.2±44.564.7±49.90.869 LSBL305.7±56.8321.9±80.30.475 TD242.5±61.3256.4±67.40.494 The differences of depth between trunks and limbs of lattice with long branches (Type IIIb) Parameters of lattice(n=74) P Trunkslimbs USBL67.1±52.5165.0±110.1<0.0001 LSBL321.9±80.3289.4±117.20.208 TD253.0±75.3125.7±40.9<0.0001 Parameters of recurrent deposits after LASIK (n=15) Parametersmean±SD (min – max) Mean depth of center of deposits84.9±43.6 (22 – 191) Mean maximum thickness85.6±24.9 (47 – 125) Mean minimum thickness45.1±18.0 (22 – 85)

12. Conclusion 1st report investigating in vivo the depth of deposits depending on the morphology Three deposits had three distinct depths  Diffuse haziness at the superficial layer  Granules at ant. stroma  Lattice deposits at mid to post. Stroma No differences of depth between two shaped lattice deposits Easily detected by RTVue-100 ® in case slit lamp examination can not reveal the depth Most of all  Guide the treatment modality according to what the main pattern of deposits are in the visual axis, such as PTK, DLKP, PKP by in vivo measuring with RTVue-100 ®