4.4Case 4

A 26-year-old female has a refractive error. As she says, her refractive error began when she was 15-year- old. The refractive error thereafter progressed slowly and became stable about 3 years ago. She is pregnant now and she feels that her vision is blurred again. She is worried especially that she has been told by the optometrist 1 month ago that she had KC.

Her MR is (Table 4.4.1):

Table 4.4.1 Manifest refraction

Her old correction (2 years ago) is (Table 4.4.2):

Table 4.4.2 Old refraction

Slitlamp examination shows clear cornea with no stress lines. Other ocular examination is within normal limits.

Corneal topography reveals posterior KC in both eyes.

For educational purposes, the right eye will be taken as an example.

Figure 4.4.1 is the right eye topography.

4.4.1Step 1: Analyzing Step

1. The patient is 26-year-old, so her age is in the border line regarding the progression of KC. But her refractive error – as she claimed and the old glasses showed – is stable.

2. She is pregnant, so she may be prone to re-progres- sion of the disease during pregnancy.

3.Her BSCVA is very good, and therefore, treatment results will be promising.

4. Corneal topography of the right eye will be taken as an example:

(a)The curvature map (Fig. 4.4.2): The axes of the central part of the bowtie are not skewed. The K-readings in the upper segment are higher than those in the inferior segment by more than 2.5 dpt. Therefore, the pattern is asymmetric bowtie / superior steep (AB/SS).

(b)The elevation maps: Fig. 4.4.3 is the anterior elevation map with the BFS reference body, Fig. 4.4.4 is the anterior elevation map with the BFTE reference body, Fig. 4.4.5 is the posterior elevation map with the BFS reference body, and Fig. 4.4.6 is the posterior elevation map with the BFTE reference body. The anterior elevation map with both reference bodies shows normal shape and values, while the posterior elevation map with both reference bodies shows abnormal shape and values. Therefore, the diagnosis is posterior KC.

5.According to Krumeich classification, it is grade 1 KC since K-readings are < 48 dpt and corneal thickness at the thinnest location is > 500 m. According to the author’s classification, it is pattern 3.

4.4.2Step 2: Management Suggestions

Table 4.4.3 summarizes patient data and the corresponding individual suggestion(s) for treatment, and presents a final summary of the best management.