Why should myopic operation do preoperative examination?

Abstract: the purpose of preoperative examination is to confirm whether the operation can be performed, eliminate potential keratoconus and severe dry eyes, And surgical contraindications such as too thin cornea (relative myopia); then provide accurate surgical data, such as corneal curvature, degree, astigmatism axis, corneal topography or wavefront aberration;

With the development of myopia surgery, the technology is more and more advanced, the equipment is more and more advanced, and the operation is more scientific and safe. A myopia operation often ends in a few minutes or more. On the contrary, the preoperative examination before myopia surgery is more critical, complex and time-consuming, which also plays an extremely important role in the safety and accuracy of myopia surgery. Why does


need preoperative examination?

exclude contraindications

the purpose of preoperative examination is to confirm whether the operation can be performed, eliminate potential keratoconus and serious dry eyes, And thin cornea (relative myopia degree) and other surgical contraindications; then provide accurate surgical data, such as corneal curvature, degree, astigmatism axis, corneal topographic map or wavefront aberration; in addition, professional preoperative examination can also screen other eye diseases, especially fundus diseases, such as fundus hemorrhage, retinal hole and detachment. In short, perfect and strict preoperative examination is to ensure the safety of operation The premise of full and effect. What preparations should be made for preoperative examination of




in fact, the complex and fine preoperative examination is to better grasp the visual acuity of myopia patients before surgery, and formulate better and more appropriate surgical plans for patients. Therefore, myopia patients do not have to be too nervous. Just relax and cooperate with the doctor for examination.


it should be noted that because mydriasis is required on the day of examination, it is best not to drive by yourself, and it is best to be accompanied by relatives and friends.

if you have the habit of wearing contact lenses at ordinary times, you need to stop wearing soft spherical lenses for more than 1 week, soft astigmatism lenses and hard contact lenses for more than 3 weeks, and corneal shaping lenses for more than 3 months.

who is suitable for myopia surgery? The applicable age of


laser myopia surgery and intraocular lens implantation is generally 18 ~ 50 years old. In addition, to accept the above two types of surgery, the patient also needs to meet the following conditions:

01. The refractive state has been relatively stable in recent two years. After preoperative examination, all eye conditions meet the operation standards;

02, no special eye diseases, such as cataract, glaucoma, keratitis, acute conjunctivitis, keratoconus, severe dry eye, no diabetes, uncontrolled systemic connective tissue disease and severe autoimmune diseases;

03. Severe amblyopia and incomplete eyelid closure are not suitable for surgery;

04. Pregnant or lactating women are not suitable for surgery for the time being.

what are the preoperative examination items of

1. Visual acuity examination

naked visual acuity and corrected visual acuity.

2. Whether the diopter of

is correct or not directly affects the surgical effect. Generally, computer optometry, retinoscopy optometry and subjective optometry are combined to accurately calculate the diopter. At the same time, the most appropriate diopter to be corrected was determined by comprehensively considering the patient’s occupation, age, corneal thickness and other factors.

3. Intraocular pressure examination

to exclude the possibility of high intraocular pressure and glaucoma. Monitor the changes of intraocular pressure before and after operation to prevent eye damage caused by postoperative hormonal high intraocular pressure.

4. Corneal topography examination

can intuitively express the anterior surface morphology of the whole cornea, understand its regularity and symmetry, eliminate the possibility of keratoconus, and monitor the changes of corneal morphology after operation.

5. Anterior segment examination

measurement of pupil diameter, including cornea, conjunctiva, anterior chamber, lens and anterior vitreous segment.

6. Fundus examination

before operation, the fundus must be carefully examined for mydriasis to eliminate fundus diseases such as retinal hole, detachment, degeneration and bleeding.

7. Corneal thickness measurement

corneal thickness plays a decisive role in the selection of surgery and the design of cutting amount. The measurement of corneal thickness will enable the operation to obtain more accurate prediction results.

8. Wavefront aberration inspection

detects the overall aberrations of human eyes, including low-order aberrations such as myopia, hyperopia and astigmatism and high-order aberrations that cannot be corrected with glasses. The personalized cutting scheme is determined according to different individuals.