What are the clinical applications of corneal topography?

The corneal topograph consists of 3 parts: ①Placido's disk projection system: 28 or 34 rings are evenly projected onto the corneal surface from the center to the periphery, so that the entire cornea is within the projection analysis range within. ②Real-time image monitoring system: The annular image projected on the corneal surface can be observed, monitored and adjusted in real time through the real-time image monitoring system, so that the corneal image is photographed in the best condition, and then stored for analysis. ③Computer image processing system: The computer first digitizes the stored images, applies the set calculation formulas and programs for analysis, and then displays the analysis results on the fluorescent screen in different color images. At the same time, the digital statistical results are also displayed together. come out.

Coreal topography analyzes the entire corneal surface, and 256 points on each projection ring are included in the processing system. Therefore, more than 7,000 data points on the entire cornea enter the analysis system. It can be seen that corneal topography is systematic, accurate and precise. Corneal topography is used clinically to diagnose corneal astigmatism, quantitatively analyze corneal properties, and display the corneal refractive index as data or different colors. The difference between the two-axis refractive index is corneal astigmatism. Diagnosis of abnormal corneal curvature. The advent of corneal topography has made it possible to diagnose subclinical keratoconus and early keratoconus, and its keratoconus diagnosis accuracy is as high as 96%. In addition, it can be used for the diagnosis of corneal distortion caused by contact lenses.

Coreal topography can also be used for preoperative examination and postoperative efficacy evaluation of corneal refractive surgery. Before surgery, corneal topography can be used to fully understand the corneal properties, especially astigmatism and exclude keratoconus and contact lenses. Induced corneal distortion; postoperative efficacy is evaluated based on corneal topography. The goal of modern cataract surgery is not only to reduce surgically induced astigmatism but also to neutralize preoperative astigmatism through the surgical incision. Therefore, the surgery can be guided based on the corneal topography examined before surgery. Use corneal topography to accurately diagnose corneal astigmatism after keratoplasty and guide the correction of astigmatism after keratoplasty. According to the corneal topography, the curvature and degree required for patients with refractive error can be calculated, and the data lens can be used to guide the wearing of corneal contact lenses, improving its accuracy.

Different radii of curvature on the cornea use different colors. Warm colors represent areas with strong refractive power, while cool colors represent areas with weak refractive power, making the results displayed on the corneal topography map very intuitive and eye-catching.

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