Currently, the classic surgical approach for primary open-angle glaucoma remains trabeculectomy (filtration surgery). However, this procedure often requires dealing with postoperative problems such as shallow anterior chamber, ciliary body choroidal detachment, filter follicle scarring, and cataracts, as well as the possibility of serious complications such as filter follicle capsulorrhaphy or even rupture and infection due to heavy use of antimetabolic drugs. In addition, for secondary glaucoma such as IOL, aphakia, and neovascularization, the success rate of surgery is significantly reduced in addition to the greater risk of complications. Therefore, both glaucoma patients and physicians have many concerns about the performance of trabecular surgery. As a result, the international search for new glaucoma surgery modalities has never stopped. In brief, North America, represented by the United States, has advocated the use of various adjunctive drainage devices to direct atrial outflow and reduce intraocular pressure. These include the familiar glaucoma drainage valve and the Ex-PRESS drainage staple. In Europe, on the other hand, the surgical approach is based on the concept of reducing ocular disturbances and increasing atrial outflow permeability, and as a result, various non-penetrating trabecular procedures have been designed. In simple terms, these represent the concepts of directing atrial water outflow and increasing permeability, respectively. In addition, the European concept is more focused on safety and minimally invasive. There is no final outcome to the debate on the two approaches. However, compared to the classic trabecular surgery, the modifications of the surgical approach are all aimed at being able to reduce scarring and maintain IOP reduction in a lasting way. In the last five years, the modifications of the surgical approach have been further broadened. In the United States, procedures characterized by intraocular filtration and minimally invasive drainage are gaining more attention. Trabecular ablation (Trabectome) and the I-Stent procedure are representatives of the internal Schlemm’s procedure; canaloplasty and dilatation (iTRACK) are representatives of the external canaloplasty; the Gold Micro-Shunt (Solx) is a representative of choroidal drainage; and the Aque-Sys procedure represents the minimally invasive external filtration procedure. In Europe, laser-assisted penetrating and non-penetrating glaucoma surgery is maturing. These evolutions reflect the convergence of two ideas, namely, the need to better guide atrial aqueous outflow and the need to increase the permeability of atrial aqueous outflow while being minimally invasive and safe (MIGS). The country is still in the position of a catcher of new technologies in the field of glaucoma treatment. It is also important to note that the problem of scarring is more prominent in the Chinese race due to the different ocular surface characteristics from the Western race. Therefore, while catching up, there is a need to improve the glaucoma procedure adapted to the Chinese population. The full name of the CLASS procedure is CO2 Laser-Assisted Sclerectomy Surgery (CO2 Laser-Assisted Sclerectomy Surgery). The new concept of this procedure is to use CO2 laser to ablate the deep sclera and the outer wall of Schlemm’s canal. The principle of IOP reduction is to reduce the resistance to atrial fluid drainage by ablating the outer wall of Schlemm’s canal, and to divert the atrial fluid to the interstitial layer of the eye wall (scleral pond) for absorption. This avoids the problems of scarring and rupture infection caused by drainage through the filter bubble. Also, because the wall of the eye is not cut through, it does not go directly into the eye, thus avoiding side effects to the interior of the eye. Patients feel very quiet and less irritated after the procedure. Laser-assisted ablation is more precise than conventional surgical excision and reduces intraoperative bleeding from the eye. The use of CO2 laser ablation prevents the laser from penetrating the eye wall, making the procedure safer and easier. The CLASS procedure has been successfully performed in more than 10,000 cases in Europe, Hong Kong and other Asian regions. In China, the procedure was just introduced in June 2015. Our hospital is the first to perform this type of surgery in China and has by far the largest number of cases and experience, and maintains cooperation with the European CLASS Surgical Association. The current surgical outcomes have found that patients’ IOP is effectively controlled in the early postoperative period. With time, a peak in IOP fluctuation may occur in the first month after surgery, and most patients can have their IOP return on its own. On the other hand, because the procedure is relatively safe and can be readily converted to conventional trabeculectomy, we believe that this type of surgery offers an additional safe treatment opportunity for patients with glaucoma. CLASS surgery is classically indicated for open-angle glaucoma and exfoliation syndrome and is not suitable for patients with closed-angle glaucoma. However, current experience has shown that CLASS surgery is also effective in juvenile glaucoma, hormonal glaucoma, uveitis glaucoma, and traumatic glaucoma. During the specific implementation, we found that the perioperative examination and treatment of CLASS surgery are more important aspects. In this regard, a different evaluation and treatment pathway exists for domestic patients than for foreign patients. We are working with our European glaucoma colleagues to further promote treatment options for Chinese glaucoma patients.