A new bleb-independent surgery namely penetrating canaloplasty for corticosteroid-induced glaucoma: a prospective case series

INTRODUCTION

Secondary intraocular pressure (IOP) elevation is common in steroid responders to glucocorticoids

. Long-term ocular hypertension may bring with glaucomatous optic nerve damage, that is, corticosteroid-induced glaucoma

. The underlying mechanism may involve increased resistance of aqueous humor in flowing through the trabecular meshwork(TM)

. Besides trabeculectomy

, a standard surgical procedures for glaucoma, corticosteroid-induced high IOP can be managed with trabeculotomy

, trabectome

,nonpenetrating deep sclerectomy

, canaloplasty

,viscocanalostomy

, gonioscopy-assisted transluminal trabeculotomy (GATT)

, Kahook Dual Blade goniotomy

,Ahmed glaucoma valve

, and XEN Gel Stent

. However,their outcomes have not been assessed with large case-control studies.

In this case series, penetrating canaloplasty was successfully performed in all the 10 eyes, and the IOP in 9 eyes was decreased without anti-glaucoma medications. Follow-up data proved the encouraging efficacy and safety of this surgery.

In the development of corticosteroid-induced glaucoma,basement membrane-like materials (positive for type IV collagen) amass in each layer of TM and fine fibrillar materials deposit beneath the inner endothelium of Schlemm’s canal

.We treated corticosteroid-induced glaucoma with penetrating canaloplasty that combines the advantages of canaloplasty(internal filtration and bleb-free) with trabculectomy (a patent communication between the anterior chamber and the Schlemm’s canal but with the sclera flap hermetically sutured).In this surgery, the aqueous humor passes through physiological route

dual conduits: Schlemm’s canal and the passage between the anterior chamber and Schlemm’s canal.Many patients with corticosteroid-induced glaucoma cannot discontinue glucocorticoids due to their primary diseases.Therefore, this dual-channel surgery can prevent the effect of TM’s further lesions during a long term. In the present study,this surgery achieved an ideal control of IOP off medication,suggesting its high efficacy for these patients.

SUBJECTS AND METHODS

3) The illuminated microcatheter (iTrack by iScience Interventional, Menlo Park, CA, USA) was then inserted and advanced through the 360° Schlemm’s canal, until out of the opposite end.

Subjects and Preoperative Examinations All patients were diagnosed with corticosteroid-induced glaucoma that was medically uncontrolled (with a definite history of corticosteroid use, IOP still rises to more than 21 mm Hg under maximal tolerable medical treatment, with concomitant glaucomatous optic disc damage and corresponding visual field defects).

Inclusion criteria: 1) corticosteroid induced high IOP; 2) IOP exceeded 30 mm Hg after maximal medical interventions,despite cessation of corticosteroid therapy (if possible) for at least 3mo; 3) fundus and visual field showed concomitant glaucomatous optic disc damage and corresponding visual field defects; 4) gonioscopy demonstrated wide and open angles and an intact Schlemm’s canal. Exclusion criteria: 1) other secondary glaucoma, 2) refusal to sign the consent form.

Surgery This surgery was pioneered by Dr. Liang YB and patented in the United States (http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2F netahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PTXT&s1=15%2F362,478&OS=15/362,478&RS=15/362,478). All 8 patients (10 eyes) underwent penetrating canaloplasty by an experienced glaucoma surgeon Liang YB. The procedures are listed below.

Use of corticosteroid was recorded. All participants received a comprehensive ophthalmic examination within one week before the surgery, which included best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, gonioscopy,IOP measurement with Goldmann applanation tonometer,fundus examination with a 90 D and non-mydriatic fundus photography, and Humphery SITA standard 24-2 perimetry,and retinal nerve fiber layer assessment with spectral-domain optical coherence tomography (OCT).

“整個世界是一塊布，將所有的人串聯起來。每個人都與我相聯系，我也與他們相聯系，就好比披肩的線。拉出其中一根，整個披肩就會塌陷。每個進入我生活的人都影響著披肩的圖案。”(389)

另外，三維模型的建立有利于材料統計工作的實施。傳統項目中的儀表材料用量通常都是估計量加裕量，主要依靠設計人員的經驗來確定，材料用量很難準確控制，容易導致施工中出現糾紛，最終的結果就是材料用量超預算采購量。在三維模型中，設計人員可以根據變送器、接線箱、閥門等儀表設備的位置，準確計算電纜、氣源管、支架等各類安裝材料數量，大幅提高了材料統計的準確性，既有利于成本控制，也能做到有據可查。

1) A superior rectus traction suture or a corneal bridle traction suture was placed to expose the surgical field, then a fornixbased conjunctival incision and a 4×4 mm

superficial scleral flap of 1/2 scleral thickness were constructed.

2) Beneath the first flap, a smaller and deeper scleral flap(2×2 mm

) was sculpted. A routine paracentesis incision was made to lower the IOP, so as to obviate the risk of trabeculodesceme membrane detachment. Schlemm’s canal was opened and unroofed by the removal of the external wall.The deep scleral flap (2×2 mm

) was then dissected away and both ostia of the canal were repeatedly visco-dilatated with high molecular weight hyaluronic acid (Healon GV), just as procedures in viscocanalostomy.

Ethical Approval This is a prospective interventional study(No.ChiCTR1900020511). The study complied with the tenets of the Declaration of Helsinki and was approved by the Ethics Committee of the eye hospital of Wenzhou Medical University(YX2018-016). Every subject voluntarily signed the consent form.

為了提高土壤肥力，促進核桃生長，在整地的時候也要及時施足基肥，基肥以有機肥為宜，或者選用充分腐熟的農家肥，每畝土地施用有機肥20-30 kg、鈣鎂磷肥1.5 kg，將肥料與土壤攪拌均勻之后施入定植穴中部，提高土壤肥力。為了提高樹苗移植成活率，在移栽之前應該要將幼苗放在水中浸泡3小時左右，或者用泥漿蘸根。苗木栽培的深度可以略微高于幼苗在原來苗圃中的深度，過淺栽培或者過深栽培都不適宜核桃生長。

4) After ligation of a 10-0 polypropylene wire to the distal tip of the microcatheter, the laser microcatheter was retreated.Every two hours, the high polymer sodium hyaluronate (Helon GV, pharmaia company, USA) was injected to expand the Schlemm’s canal with the aid of a special screw-driven syringe.After the withdrawal of the microcatheter, the suture was then replaced in the Schlemm’s canal. After the Schlemm’s canal was fully expanded, the suture was knotted under tension.

5) The trabecular tissue (2×2 mm

) deep at Schlemm’s canal was cut off and forwarded. The respective iris root was cut.

Basic characteristics of the patients are summarized in Table 1.The mean follow-up time was 20.4±13.0mo (range 6-48mo).The mean preoperative IOP and number of anti-glaucoma medications were 45.1±6.5mm Hg and 3.3±0.5, respectively.The mean IOP at 3, 6, 12, 18, 24, 36, and 48mo were 15.8±6.0,14.7±3.3, 15.3±2.0, 15.6±2.6, 17.5±1.8, 16.5±4.9, and 14.0 mm Hg, respectively. The number of anti-glaucoma medications at these time points were all 0 (Table 2). IOP was well controlled in 9 cases off medication, but not reduced in 1 eye of a patient at 1mo after the surgery. Then this patient received ultrasound cycloplasty, trabeculectomy with mitomycin C (MMC), needling subsequently in the following 7mo, but all failed. A drainage valve was implanted at last. At last follow-up, the IOP in this case dropped to 18.5 mm Hg.Gonioscopy confirmed that prolene sutures were precisely positioned within the Schlemm’s canal for the entire follow-up period in all cases. UBM after penetrating canaloplasty shows no subconjunctival filtration bleb (Figure 2). Microhyphaema occurred in 3 eyes, but disappeared within one week through spontaneous absorption. Postoperative transient IOP spike occurred in two eyes which cropped up from one week to one month after surgery. One eye developed choroidal detachment which responded well to conservative treatment. No other complications were observed during or after the surgery. For uveitic eyes, two eyes had no recurrence of the inflammation postoperatively, four eyes had varying degrees of uveitis reactivation and an addition of corticosteroid.

5.面板方差分解技術。面板方差分解分析京津冀城市群土地綜合承載力與區域經濟發展系統每一個標準差新息沖擊對土地綜合承載力、人均GDP、地均第二、第三產業增加值變量變化的方差貢獻度。[17]首先進行皮爾森……