Glaucomul

Trabeculectomy or glaucoma surgery

Trabeculectomia este o procedură chirurgicală eficientă pentru tratamentul glaucomului. Această operație glaucom vizează scăderea presiunii intraoculare prin crearea unei noi căi de drenaj pentru fluidul ocular. Trabeculectomia este considerată o metodă standard în chirurgia glaucomului, oferind o opțiune viabilă pentru pacienții cu glaucom necontrolat prin terapia medicamentoasă. În acest articol, vom explora în detaliu ce este trabeculectomia și cum funcționează această intervenție chirurgicală în tratarea glaucomului.

Introducere

Glaucoma is a heterogeneous group of eye diseases characterized by damage to the optic nerve with structural and functional changes. It is the second leading cause of blindness worldwide due to ophthalmological conditions in the adult population (aged 18-65 years) and the leading cause of irreversible blindness. The most important feature of glaucoma is its slow onset and lack of pain, leading to late diagnosis.

Glaucomatous optic neuropathy has multiple etiologies and is characterized by loss of retinal ganglion cells and their axons.

Increased intraocular pressure is the most important risk factor for developing glaucoma.

1. Classification of glaucomas

It will be done in primary and secondary, open or closed angle, congenital or adult, the criteria for classification being:

Age of appearance
Gonioscopy
Biomicroscopy
Ophthalmoscopy
Perimetry
Presence of pseudoexfoliation
Pigment dispersion or neovases

2. Glaucoma treatment

Antiglaucomatous treatment will be tailored according to the stage of the disease, the severity of functional impairment and the age of the patient. The goal of antiglaucomatous therapy is to achieve the target intraocular pressure. There are several ways to treat glaucoma:

Drug therapy

Selective alpha 2 adrenergic agonists: Brimonidine

Beta blocker
beta1 non-selective: Betaxolol
non-selective beta2: Timolol

Carbonic anhydrase inhibitors
topics: Brinzolamide and Dorzolamide
systemic: Acetazolamide

Prostaglandin derivatives: Bimatoprost, Latanoprost, Travoprost, Tafluprost
- Systemic hyperosmotic agents indicated in acute increases in intraocular pressure: Mannitol

Laser therapy

Iridotomie laser Nd:Yag

- Laser iridoplasty

- Trabeculoplasty

– Ciclofotocoagulare laser transsclerala micropulsată

Surgical therapy

Chirurgia penetrantă: trabeculectomia și trabeculotomia

Non-penetrating surgery: deep sclerectomy

3. Trabeculectomy

Trabeculectomy is a penetrating surgery performed to reduce intraocular pressure in patients with glaucoma. The way to reduce intraocular pressure is by creating a protected fistula between the inner parts of the eye (anterior chamber) and the subconjunctival space, forming a filtering cushion.

The success rate may vary depending on the clinical type of glaucoma. Thus, the glaucomas that have the best success rate are: primary open-angle glaucoma, primary closed-angle glaucoma, pseudoexfoliation syndrome, pigmentary glaucoma, angle recession, pseudophakia. And glaucomas with the lowest success rate are: neovascular glaucoma, uveitic glaucoma, congenital glaucoma and more than 2 unsuccessful filtering procedures.

The success rate after trabeculectomy using intraoperative antimetabolites is 74%, visual acuity stabilization is 100% and stationary visual field appearance is 94%.

4. Directions

Trabeculectomy is indicated as a treatment for glaucoma when drug therapy and laser procedures have failed to control intraocular pressure. Other indications for performing the procedure are:

- When patient compliance with drug therapy is low or side effects are unacceptable

- If it is necessary to achieve a target intraocular pressure that would be impossible to achieve by other forms of therapy, in patients with rapidly progressing disease

- Advanced glaucoma with very high intraocular pressure at diagnosis

5. Operating technique

Pre-operatively, the patient is informed of the operative steps, a series of blood tests will be requested and the therapeutic management will be established if the patient is under chronic treatment with anticoagulant or antiaggregant drugs.

The procedure takes place in the operating theatre. Anaesthesia can be locoregional, with a parabobar injection, or general in special cases (non-operative patient or child).

The duration of the intervention is approximately 45-60 min.

Description of the intervention:

The eye will be anaesthetised, disinfected and covered with a sterile drape. During the operation the patient will feel the doctor's movements but will not feel any pain. The pupil is in myosis. A conjunctival flap is made in the upper portion of the eye with the base at the corneo-scleral limbus.

Clean the episcleral tissue and cauterize the blood vessels. Antimetabolites (5 fluoro-uracil) are used under the conjunctival flap to prevent fibrosis of the filter cushion and to have a higher and longer-lasting trabeculectomy success rate. A scleral lamellar flap is performed, followed by trabeculectomy and peripheral iridotomy. The scleral flap is sutured and then the conjunctivotenoid flap.

The eye is bandaged and stays that way until the next day when the first postoperative visit is due.

6. Postoperative treatment

Treatment after trabeculectomy consists of ocular instillations with antibiotic and anti-inflammatory for one month and continued treatment with local steroids for up to 3 months, with gradual tapering of the dose.
Cycloplegic treatment is used in special cases such as narrow anterior chamber or ocular hypotonia.

Postoperatively, massage of the sclera is indicated to promote increased drainage and ensure the patency of the operation for the formation of the filtration cushion.
Removal of the hairs will be done 2 weeks postoperatively, in the office, after prior instillation with anaesthetic drops.
Regular check-ups are performed at 4 days, 1 week and 1 month postoperatively under the treatment
applied, to check the healing process and monitor intraocular pressure.

Following trabeculectomy it is possible that the patient may be left with fewer or, less commonly, no eye drops administered to reduce intraocular pressure.

Postoperatively, some activities such as swimming and sports in general should be avoided.

Descoperiți mai multe informații valoroase despre oftalmologie și sănătatea ochilor vizionând materialele realizate de experți în domeniu de pe canalul nostru de YouTube.

[1] Ophthalmology Treatise Marieta Dumitrache, University Publishing House "Carol Davila" Bucharest 2012
[2] Kanski's clinical ophthalmology
[3] https://pubmed.ncbi.nlm.nih.gov/11148811/

Oftalmologie Timisoara - Doctor oftalmolog Timisoara - Dr. Manuela Buzescu, Medic primar oftalmolog

Dr Buzescu Manuela Primary Ophthalmologist

- 13th July 2022

Glaucoma