2형 오브스캔 각막지형도를 이용한 원추각막과 원추각막의증의 각막형태비교 1599
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Figure 1. The map of Orbscan II topography in keratoconus. The parameters including central corneal power, anterior and posterior elevation from BFS and central corneal thickness are significantly different from normal eyes. Figure 2. The map of Orbscan II topography in keratoconus suspect. Anterior elevation from BFS is the only significantly different parameter comparing with normal eyes, and central corneal power, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness are the parameters significantly different from keratoconic eyes. 1601
Table 1. Comparison of parameters of Orbscan II system in keratoconic and normal eyes. The parameters including central corneal power, anterior and posterior elevation from BFS and central corneal thickness are significantly different from normal eyes Parameter Keratoconic eye Normal eye p-value Central corneal power (Diopter) 48.81±6.33 (37.60~72.06) 42.48±1.71 (38.98~44.81) Anterior elevation from BFS * (µm) 43.05±27.26 6.80±4.91 Posterior elevation from BFS * (µm) (4.00~125.00) 93.93±54.64 (1.00~14.00) 25.70±7.13 Central corneal thickness (µm) (9.00~225.00) 451.07±61.01 (15.00~41.00) 543.65±44.24 (282.00~560.00) (441.00~611.00) Anterior chamber depth (mm) Corneal diameter (mm) Pupil size (mm) 3.34±0.36 (2.64~4.04) 11.74±0.36 (11.10~12.50) 4.91±1.48 (3.20~10.80) 3.07±0.23 (2.73~3.47) 11.56±0.45 (11.10~13.00) 5.15±1.44 (3.70~8.00) 0.024 0.104 0.564 * : Best-fit sphere. (By Scheffe s method) Table 2. Comparison of parameters of Orbscan II system in keratoconus-suspected and normal eyes. Anterior elevation from BFS is the only significantly different parameter compared with normal eyes Parameter Keratoconus-suspected eye Normal eye p-value Central corneal power (Diopter) 42.74±1.59 (40.32~46.12) 42.48±1.71 (38.98~44.81) 0.999 Anterior elevation from BFS * (µm) 24.28±7.65 6.80±4.91 0.014 Posterior elevation from BFS * (µm) (6.00~37.00) 30.72±19.03 (1.00~14.00) 25.70±7.13 0.591 Central corneal thickness (µm) (1.00~64.00) 501.84±55.34 (15.00~41.00) 543.65±44.24 0.065 (362.00~580.00) (441.00~611.00) Anterior chamber depth (mm) Corneal diameter (mm) Pupil size (mm) 3.27±0.35 (2.45~3.83) 11.81±0.43 (10.80~12.50) 4.95±1.24 3.07±0.23 (2.73~3.47) 11.56±0.45 (11.10~13.00) 5.15±1.44 0.188 0.101 0.662 (3.40~7.80) (3.70~8.00) * : Best-fit sphere. (By Scheffe s method) 1602
Table 3. Comparison of parameters of Orbscan II system in keratoconic and keratoconus-suspected eyes. Central corneal power, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness are the parameters significantly differed from keratoconus-suspected eyes Parameter Keratoconic eye Keratoconus suspected eye p-value Central corneal power (Diopter) 48.81±6.33 (37.60~72.06) 42.74±1.59 (40.32~46.12) Anterior elevation from BFS * (µm) 43.05±27.26 24.28±7.65 0.980 Posterior elevation from BFS * (µm) (4.00~125.00) 93.93±54.64 (6.00~37.00) 30.72±19.03 Central corneal thickness (µm) (9.00~225.00) 451.07±61.01 (1.00~64.00) 501.84±55.34 0.003 (282.00~560.00) (362.00~580.00) Most protruded corneal thickness (µm) Anterior chamber depth (mm) Corneal diameter (mm) Pupil size (mm) 440.05±66.38 (280.00~560.00) 3.34±0.36 (2.64~4.04) 11.74±0.36 (11.10~12.50) 4.91±1.48 (3.20~10.80) 497.38±59.13 (362.00~579.00) 3.27±0.35 (2.45~3.83) 11.81±0.43 (10.80~12.50) 4.95±1.24 (3.40~7.80) 0.001 0.845 0.563 0.924 * : Best-fit sphere. (By Scheffe s method) 1603
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Corneal Topographic Study Using Orbscan II between Keratoconus and Keratoconus Suspect Seung Uk Lee, M.D. 1, Chang Hwan Lee, M.D. 2, Ji-Eun Lee, M.D., Ph.D. 1, Jong Soo Lee, M.D., Ph.D. 1 Department of Ophthalmology, College of Medicine, Pusan National University 1, Pusan, Korea Department of Ophthalmology, Wallace Memorial Baptist Hospita 2, Pusan, Korea Purpose: To compare corneal topographic changes using Orbscn II between keratoconus and keratoconussuspected eyes. Methods: Thirty-seven keratoconus eyes, 17 keratoconus-suspected eyes and 37 normal eyes were evaluated by using Orbscan II corneal topography. We compared central phachymetry, anterior elevation from best-fit sphere (BFS), posterior elevation from BFS, most protruded corneal thickness, central corneal thickness, anterior chamber depth, corneal diameter, and pupil size. Results: Central pachymetry, anterior and posterior elevation from BFS, central corneal thickness, and anterior chamber depth were statistically significantly different between keratoconus and control eyes. Anterior elevation from BFS showed a significant difference between keratoconus-suspected and control eyes. There were statistically significant differences in central pachymetry, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness between keratoconus and keratoconus-suspected eyes. Corneal diameter and pupil size showed no differences among the 3 groups. Conclusions: Suspected keratoconus eyes have a higher value of anterior elevation from BFS on Orbscan II topography as compared with control eyes. Central pachymetry, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness may be helpful in distinguishing between keratoconus and keratoconus-suspected eyes. J Korean Ophthalmol Soc 48(12):1599-1606, 2007 Key Words: Anterior chamber depth, Best fit sphere (BFS), Keratoconus, Keratoconus suspect, Orbscan II corneal topography 1606