Most children with glaucoma need surgery, often in their young years. Ab-externo surgeries are a key treatment for primary congenital glaucoma (PCG). This rare condition affects kids under 5. The goal is to improve drainage and lower eye pressure to prevent damage and vision loss.
This guide will cover the different ab-externo surgeries for infant glaucoma. We’ll look at trabeculotomy, goniotomy, and more. We’ll also talk about new surgical methods, care after surgery, and how well these treatments work. This information will help you make the best choice for your child’s treatment.
Key Takeaways
- Ab-externo surgeries are a common treatment approach for primary congenital glaucoma in children under 5 years old.
- These procedures aim to improve drainage and lower eye pressure, preventing optic nerve damage and vision problems.
- Various ab-externo surgical techniques are available, including trabeculotomy, goniotomy, and combined trabeculotomy-trabeculectomy.
- Antifibrotic agents like Mitomycin C can be used to enhance the success of these procedures.
- Emerging surgical innovations and postoperative management are also discussed in this comprehensive guide.
Primary Congenital Glaucoma: Overview and Definition
Primary congenital glaucoma (PCG) is a rare eye condition. It causes high eye pressure in young children. This condition is not linked to other health issues.
The rate of PCG varies worldwide. It’s more common in Eastern Europe, affecting 1 in 1,250 children. In Western countries, it’s much rarer, affecting 1 in 20,000 children.
Epidemiology and Demographics
PCG is more common in children from families where both parents are related. This is because of genetic factors. It often affects both eyes, happening in 65-80% of cases.
In the UK and Europe, boys are more likely to have PCG than girls. The ratio is about 3 boys for every 2 girls.
Etiology and Pathophysiology
Most cases of PCG happen by chance. But 10-40% are inherited, following an autosomal recessive pattern. Several genes are linked to PCG, including GLC3A, GLC3B, GLC3C, GLC3D, and GLC3E.
The GLC3A locus has the CYP1B1 gene. This gene is the main cause of PCG in many places. It affects 15-20% of cases in the US and Japan, and up to 100% in some areas.
CYP1B1 mutations lead to high eye pressure. This is because the protein it makes is not developed properly. Other genes, like LTBP2 and TEK, also play a role in PCG. They are involved in the development of the Schlemm’s canal and the angiopoietin/TEK signalling pathway.
| Genetic Locus | Gene | Contribution to PCG |
|---|---|---|
| GLC3A | CYP1B1 | Most common genetic cause, accounting for 15-20% of cases in the US and Japan, and up to 100% in some populations |
| – | LTBP2 | Plays a role in the development of Schlemm’s canal |
| – | TEK | Involved in the angiopoietin/TEK signalling pathway, crucial for proper aqueous humour drainage |
The exact pathophysiological mechanisms by which these genetic factors contribute to PCG are still being elucidated.
Diagnosis of Primary Congenital Glaucoma
Clinical Presentation and Signs
The classic symptoms of primary congenital glaucoma (PCG) are photophobia, epiphora, and blepharospasm. These happen because the child’s eye grows too fast. This causes the eyeball to get bigger, the cornea to grow, and breaks in Descemet’s membrane.
Corneal edema and opacification can also occur. Not all symptoms are present all the time. Bilateral PCG might be missed if symptoms are mild in one eye. Diagnosis can be tricky if the corneas look clear but are enlarged.
Diagnostic Procedures and Differential Diagnosis
To diagnose PCG, doctors measure intraocular pressure (IOP) and check the optic nerve. They also look at the anterior chamber angle. Tests like gonioscopy, ultrasound biomicroscopy, and corneal diameter measurements are used.
It’s important to rule out other causes of childhood glaucoma. This includes conditions like Axenfeld-Rieger syndrome, aniridia, and Peters anomaly. The child’s medical and family history, along with a full eye exam, help make the right diagnosis.
“Surgical options such as angle surgery, specifically goniotomy and trabeculotomy, show success rates ranging from 70% to 90%.”
Paediatric glaucoma is a big cause of treatable childhood blindness. Early diagnosis and treatment are key to saving vision and preventing damage.
Ab-externo Surgeries for Glaucoma in Infants
Childhood glaucoma is a tough condition that needs early treatment to save vision. Ab-externo surgeries are key in managing primary congenital glaucoma (PCG). They fix the eye’s problems that cause high pressure.
These surgeries make cuts on the eye’s outside to help fluid drain better. This lowers the eye pressure.
The most common ab-externo surgeries for PCG are:
- Trabeculotomy
- Goniotomy
- Combined trabeculotomy and trabeculectomy
- Trabeculectomy with the use of antifibrotic agents
These treatments are the main way to deal with PCG. They aim to fix the eye’s problems. New and emerging surgeries are also being looked into to better help kids with this condition.
| Surgical Approach | Description | Success Rates |
|---|---|---|
| Trabeculotomy | Incision of the trabecular meshwork to improve aqueous drainage | 80-90% success in PCG cases presented between 1 month and 1 year of age |
| Goniotomy | Incision of the trabecular meshwork through the anterior chamber | 30-90% success rates, depending on factors like timing of diagnosis and corneal clarity |
| Combined Trabeculotomy and Trabeculectomy | Combination of angle surgery and creation of a filtration bleb | Variable success rates, particularly in advanced disease cases |
| Trabeculectomy with Antifibrotic Agents | Filtration surgery with the use of mitomycin C or other adjuvants to reduce scarring | Improved success rates compared to traditional trabeculectomy |
The right surgery for childhood glaucoma depends on the type, how bad it is, and the child’s age. Working together, doctors and researchers are finding new ways to help kids with glaucoma.
Trabeculotomy Ab Externo
Surgical Technique
Trabeculotomy ab externo was first described by Burian in 1960. It’s a common surgery for primary congenital glaucoma (PCG). The surgery makes an incision in the sclera to reach the trabecular meshwork.
This creates an opening to improve drainage of aqueous humour. A probe is used to make this opening. New techniques, like using microcatheters, have been developed to make the surgery better.
Outcomes and Complications
Trabeculotomy ab externo is effective for PCG, with success rates from 60-90%. But, long-term success can be lower, with up to 50% failure within 5 years.
Complications include hyphema, scleral perforation, and shallow anterior chamber. Choosing the right patient, using precise surgical techniques, and monitoring closely are key. This helps improve results and reduces risks.
| Outcome Measure | Value |
|---|---|
| Mean IOP preoperatively | 33.16±7.28 mmHg |
| Mean IOP postoperatively | 21.41±7.34 mmHg |
| Success rates at 12 months | 92% |
| Success rates at 24 months | 82% |
| Success rates at 36 months | 74% |
| Preoperative axial length as predictor of success | Statistically significant |
| Patients achieving normal corneal clarity | 80.5% |
| Shallow anterior chamber | 4.2% of cases |
| Descemet’s membrane detachment | 8.4% of cases |
The success of trabeculotomy ab externo depends on several factors. These include preoperative axial length and careful patient selection. Doctors must consider the benefits and risks to get the best results for infants with PCG.
Goniotomy
Goniotomy is a surgical technique for primary congenital glaucoma (PCG). It makes an incision in the cornea to reach the trabecular meshwork. This creates a pathway for better fluid drainage, lowering eye pressure and easing glaucoma symptoms.
Types of Goniotomy Procedures
Over time, different goniotomy methods have been developed. Each has its own benefits for PCG patients. Some key advancements include:
- Using sodium hyaluronate to improve visibility during surgery, helping the surgeon target the trabecular meshwork more accurately.
- Endoscopic goniotomy, which uses a small camera for a more precise and less invasive surgery.
Researchers are still studying these techniques to see which works best for PCG patients. They aim to make the procedure even better and improve results for patients.
| Study | Findings |
|---|---|
| Elhilail et al. (2021) | Prospective study on Kahook Dual Blade (KDB) in 21 PCG eyes. Preoperative IOP of 24.4±6.8 mmHg reduced to 11.8±2.3 mmHg at 12-month follow-up, with a success rate (IOP ≤21 mmHg) of 57.1%. |
| Grover et al. (2014) | Retrospective study on Gonioscopy-assisted Transluminal Trabeculotomy (GATT) in 14 childhood glaucoma eyes (4 PCG, 10 JOAG). Mean preoperative IOP of 27.3 mmHg on 2.6 medications reduced to 14.8 mmHg on 0.86 medications, with a failure rate of 48.6% at a median follow-up of 28.5 months. |
| Shi et al. (2021) | Prospective study on GATT in 70 JOAG eyes. Mean baseline IOP of 31.3±9.5 mmHg reduced to 15.8±2.7 mmHg at 1-year follow-up, with a success rate (IOP ≤21 mmHg, ≥20% reduction) of 91.4% (qualified) and 74.3% (complete). |
These studies show the potential of goniotomy techniques in managing PCG and other childhood glaucoma. They highlight the ongoing development and benefits of these methods.
Combined Trabeculotomy and Trabeculectomy
Some surgeons use a combined trabeculotomy and trabeculectomy procedure for PCG. This method creates an opening in the trabecular meshwork and a filtration bleb through the sclera. It aims to improve aqueous drainage by addressing several potential blockages.
Research shows mixed results, with some success but also more risks. A study on 19 eyes of 12 children with PCG found interesting data:
- 67% of infants had bilateral disease.
- Mean age at diagnosis was 4.4 months, with surgery performed at a mean age of 5.9 months.
- 79% of eyes achieved complete success (intraocular pressure
- Probability of success decreased from 94.4% at 3 months postoperatively to 13.3% at 21 months postoperatively (Kaplan–Meier analysis).
- 63% of eyes had well-functioning blebs at the last follow-up.
- One eye (5%) developed seclusio pupillae and cataract postoperatively.
Another study with 74 patients and 121 eyes found a success rate of 79% in Ghanaian children. Success rates dropped from over 66% in the first 9 months to below 45% after that.
The combined method might offer better results than single procedures. However, it’s vital to consider each patient’s unique situation. Close monitoring and proper care after surgery are key to achieving the best results.
Trabeculectomy with Antifibrotic Agents
Trabeculectomy is a surgery that helps drain fluid from the eye. It’s often done with antifibrotic agents like mitomycin C for better results in primary congenital glaucoma (PCG). Mitomycin C stops the eye from healing too much and prevents scarring.
Other agents, like 5-fluorouracil, are also used to boost the surgery’s success. But, using these drugs can lead to more problems, such as eye pressure drops, leaks, and infections.
Use of Mitomycin C and Other Adjuvants
Despite these risks, studies show that trabeculectomy with mitomycin C can work well for PCG. Success rates range from 70% to 90%, averaging around 80%.
In Ghana, a study found that 12 patients with PCG had good results. Eighty percent of them had eye pressure under 21 mm Hg after surgery. Success rates were high at 3, 6, and 9 months post-op.
| Outcome | Percentage |
|---|---|
| Surgical success (IOP | 79% |
| Clear cornea at last follow-up | 90% |
| Well-functioning blebs at last follow-up | 63% |
| Complication (seclusio pupillae and cataract) | 5% |
Using antifibrotic agents like mitomycin C with trabeculectomy can improve PCG surgery results. But, doctors must watch for and handle any side effects carefully.
Novel and Emerging Surgical Techniques
Researchers and clinicians are always looking for new ways to treat primary congenital glaucoma (PCG). They are exploring glaucoma drainage devices, like the Ahmed valve, and minimally invasive glaucoma surgery (MIGS). These methods aim to lower eye pressure in a more precise and gentle way.
They are also looking into adjuvant therapies, such as gene therapy and stem cell treatments. These could make surgeries for PCG more effective. These new methods might lead to better results and fewer side effects for kids with this condition.
Glaucoma Drainage Devices
Glaucoma drainage devices, like the Ahmed valve, are being considered for PCG treatment. They help drain fluid from the eye, which can lower pressure. This might be a more precise and less invasive option than older surgeries.
Minimally Invasive Glaucoma Surgery (MIGS)
MIGS is another promising approach for PCG. It includes procedures like trabecular bypass stents and suprachoroidal shunts. These aim to improve the eye’s natural drainage with smaller, less invasive surgeries. MIGS could offer a safer way to reduce eye pressure.
Adjuvant Therapies
- Gene therapy: Scientists are studying gene-based treatments to tackle PCG’s genetic roots. They hope these can boost the success of surgeries.
- Stem cell-based treatments: Researchers are exploring stem cell therapies to repair or replace damaged eye parts. This could help improve surgery outcomes.
These new surgical methods and adjuvant therapies could greatly help in managing PCG. They might improve the lives of children with this condition. Ongoing research and trials will help shape the future of treating PCG.
Postoperative Management and Follow-up
After surgery for primary congenital glaucoma (PCG), careful management is key. This means watching the eye pressure closely and checking the surgery site. It also means looking out for problems like hyphema, shallow chambers, or issues with the bleb.
Some patients might need extra treatments or more surgery to keep the eye pressure right. They also need to see their doctors often, even into adulthood. This is because PCG is a lifelong condition, and regular check-ups are vital for the best results.
- Close monitoring of IOP: Regular measurements of IOP are essential to detect and manage any fluctuations or increases that may occur following ab-externo surgeries.
- Assessment of the surgical site: Regular examinations of the surgical area are necessary to evaluate the healing process, identify any complications, and determine the need for further interventions.
- Vigilance for complications: Healthcare professionals must be alert to potential complications, such as hyphema, shallow anterior chamber, or bleb-related issues, and address them promptly to prevent vision loss.
- Additional medical therapy: Patients may require supplementary medical treatments, such as eye drops or oral medications, to maintain adequate IOP control and prevent further damage to the optic nerve.
- Needling procedures: In some cases, needling procedures may be necessary to address scarring or bleb-related issues and improve the functioning of the surgical site.
- Further surgical interventions: If IOP control cannot be maintained through medical therapy or needling procedures, additional surgical interventions may be necessary to address the underlying glaucoma.
Seeing doctors often, even into adulthood, is crucial for managing PCG. This ensures the best care for these patients. It’s important for doctors and patients to work together closely to manage this complex condition and protect vision for life.
“Successful management of primary congenital glaucoma requires a multidisciplinary approach, with close collaboration between ophthalmologists, optometrists, and other healthcare professionals to provide comprehensive, patient-centred care.”
Conclusion
Primary congenital glaucoma is a rare but serious eye condition in children. It needs quick and effective surgery to avoid vision loss and blindness. Techniques like trabeculotomy, goniotomy, and trabeculectomy are key in treating PCG. Ongoing research aims to make these treatments better and safer.
Choosing the right patients, using precise surgical methods, and careful aftercare are crucial. As we learn more about PCG’s causes and how it works, we’re getting closer to better treatments. This will help children and their families a lot.
New surgical methods and a better understanding of the disease are promising. They could lead to better vision and a better life for kids with this condition. Working together, we can make a big difference in the care of children with primary congenital glaucoma.
FAQ
What is primary congenital glaucoma (PCG)?
Primary congenital glaucoma (PCG) is a rare eye condition in children under 5. It happens when the eye’s drainage system doesn’t work right. This can cause high eye pressure. If not treated, it can lead to vision loss and blindness.
What are ab-externo surgeries for glaucoma in infants?
Ab-externo surgeries are done on the outside of the eye. They help improve drainage and lower eye pressure. These surgeries are used to treat PCG and prevent vision problems.
What are the main types of ab-externo surgical techniques used to manage PCG?
There are several ab-externo surgical methods for PCG. These include trabeculotomy, goniotomy, and trabeculectomy. New techniques are also being developed to improve treatment results.
What is the success rate of trabeculotomy ab externo for PCG?
Trabeculotomy ab externo is a successful treatment for PCG. Studies show it works for 60-90% of patients. But, success rates can drop to 50% within 5 years.
What are the potential complications of ab-externo surgeries for PCG?
Ab-externo surgeries can have complications like hyphema and shallow anterior chamber. Choosing the right patient and using precise surgical techniques are key. Close monitoring after surgery is also important to avoid complications.
How is postoperative management and follow-up handled for patients undergoing ab-externo surgeries for PCG?
Postoperative care is critical for PCG patients. It involves monitoring eye pressure and checking the surgical site. Patients may need ongoing medical treatment or further surgery to control eye pressure and prevent vision loss.
