Visual Disability Among Juvenile Open-angle Glaucoma Patients

Machine learning-assisted prediction of trabeculectomy outcomes among patients of juvenile glaucoma by using 5-year follow-up data

OBJECTIVE

To develop machine learning (ML) models, using pre and intraoperative surgical parameters, for predicting trabeculectomy outcomes in the eyes of patients with juvenile-onset primary open-angle glaucoma (JOAG) undergoing primary surgery.

SUBJECTS

The study included 207 JOAG patients from a single center who met the following criteria: diagnosed between 10 and 40 years of age, with an IOP of >22 mmHg in the eyes on two or more occasions, open angle on gonioscopy in both eyes, with glaucomatous optic neuropathy, and requiring a trabeculectomy for IOP control. Only the patients with a minimum 5-year follow-up after surgery were included in the study.

METHODS

A successful surgical outcome was defined as IOP ≤18 mmHg (criterion A) or 50% reduction in IOP from baseline (criterion B) 5 years after trabeculectomy. Feature selection techniques were used to select the most important contributory parameters, and tenfold cross-validation was used to evaluate model performance. The ML models were evaluated, compared, and prioritized based on their accuracy, sensitivity, specificity, Matthew correlation coefficient (MCC) index, and mean area under the receiver operating characteristic curve (AUROC). The prioritized models were further optimized by tuning the hyperparameters, and feature contributions were evaluated. In addition, an unbiased relationship analysis among the parameters was performed for clinical utility.

RESULTS

Age at diagnosis, preoperative baseline IOP, duration of preoperative medical treatment, Tenon's thickness, scleral fistulation technique, and intraoperative mitomycin C (MMC) use, were identified as the main contributing parameters for developing efficient models. The three models developed for a consensus-based outcome to predict trabeculectomy success showed an accuracy of >86%, sensitivity of >90%, and specificity of >74%, using tenfold cross-validation. The use of intraoperative MMC and a punch for scleral fistulation compared to the traditional excision with scissors were significantly associated with long-term success of trabeculectomy.

CONCLUSION

Optimizing surgical parameters by using these ML models might reduce surgical failures associated with trabeculectomy and provide more realistic expectations regarding surgical outcomes in young patients.

Myocilin Mutation N480K Leads to Early Onset Juvenile and Adult-onset Primary Open Angle Glaucoma in a Six Generation Family

PRCIS

A pathogenic autosomal dominant MYOC mutation N480K detected in 6 generations of an Indian family is primarily responsible for juvenile open angle glaucoma (JOAG) and adult-onset primary open angle glaucoma (POAG), emphasizing the importance of screening this mutation at a younger age.

PURPOSE

To screen myocilin mutations in a large South Indian family with early-onset JOAG and adult-onset POAG.

METHODS

In a large South Indian family with 20 members, 8 members diagnosed as JOAG, 7 members as POAG, 4 members as JOAG suspect, and 1 member as POAG suspect were screened for myocilin ( MYOC) mutations using Sanger sequencing. Whole exome sequencing was performed on clinically suspected JOAG/POAG individuals.

RESULTS

Myocilin gene mutation N480K (c.1440C>G) was detected in 20 family members, including proband, of whom 8 were JOAG and 7 were POAG patients, 3 were JOAG suspects, and 2 were unaffected. Among the unaffected carriers, 1 was less than 5 years old, and another was 25 years old. The earliest to develop the disease was a 10-year-old child. The penetrance of the mutation was 95% over 10 years of age. This family had JOAG/POAG suspects with no N480K MYOC mutation, and they were further screened for other mutations using whole-exome sequencing. Polymorphisms CYP1B1 L432V and MYOC R76K were detected in 3 JOAG/POAG suspects, and among these 3, one had another CYP1B1 polymorphic variant R368H. The presence of the CYP1B1 polymorphism along with an MYOC polymorphic variant among the JOAG/POAG suspects needs additional studies to explore their combined role in the onset of glaucoma.

CONCLUSIONS

This study reveals that MYOC mutation is primarily responsible for JOAG and adult-onset POAG in a family, emphasizing the importance of screening for this mutation at a younger age for early treatment.

Treatment Outcomes for Juvenile Open Angle Glaucoma in Thailand

PRCIS

Juvenile open angle glaucoma (JOAG) patients with thick central corneas and negative family history were more likely to undergo surgery, mainly trabeculectomy with half requiring additional surgery within 10 years.

PURPOSE

To assess the characteristics and treatment outcomes of patients with JOAG in Thailand.

PATIENTS AND METHODS

This retrospective, multicenter study included all patients diagnosed with JOAG over 12 years from 2 tertiary hospitals in Bangkok, Thailand.

RESULTS

A total of 200 eyes from 104 patients were included in this study. The mean age of onset was 24.0±10.1 years (range: 5-40 y), with male predominance (60.5%). Over 90% of patients had bilateral JOAG and 25% had a positive family history. Negative family history (adjusted odds ratio=4.59, P =0.02) and thick central corneal thickness were surgical predictors (every 10 µm adjusted odds ratio=1.29, P =0.01). Over 70% of cases needed glaucoma surgery. Trabeculectomy with Mitomycin-C was performed on 131 eyes (65.5%) with a cumulative probability of complete success of 71.0%, 57.8%, 39.2%, and 26.9% and qualified success of 86.3%, 73.6%, 64.8%, and 45.7% at 1, 3, 5, and 10 years, respectively. The mean follow-up after surgery was 94.9 ± 69.8 months (range: 13-153 mo). There were no serious postoperative complications. Myopia and the number of baseline glaucoma medications were significantly associated with surgical failure.

CONCLUSIONS

Trabeculectomy with mitomycin C was the most common primary surgery performed in Thai patients with JOAG, and successfully reduced intraocular pressure without significant complications. Patients with thicker corneas were more likely to undergo surgery. By 10 years, half of the patients required additional surgery and risk factors for failure included myopia and the number of medications.

Clinical and demographic profile of patients less than 40 years of age presenting to glaucoma services at a tertiary care eye hospital in South India

Purpose

To study the clinical and demographic profile of patients less than 40 years of age presenting to glaucoma services including the reasons for referral.

Methods

Patients in the age group of 5 to 39 years, visiting the glaucoma clinic, who were either suspected to have glaucoma or who had been newly/previously diagnosed with glaucoma were included in the study. After informed written consent, basic demographic details of the participants including age, gender, education, socioeconomic status, and family history were obtained. A comprehensive ophthalmological evaluation was performed by glaucoma specialists.

Results

The proportion of glaucoma in the study population (n = 384) was found to be 31.25%, and the incidence of glaucoma among new patients was found to be 11.9%. Among all glaucomas (n = 120), 44.2% of patients had secondary glaucomas, 27.5% had primary glaucomas, and 28.3% had congenital glaucomas. Also, 67.3% of all glaucoma patients were males. Newly diagnosed glaucoma patients presented with a mean intraocular pressure (IOP) of 32.9 mmHg and mild-moderate disc damage with a mean cup-disc ratio of 0.65. Nearly one-third of them had a presenting visual acuity worse than 5/60. The most common reason for referral was raised IOP. Univariate and multivariate analysis revealed that the odds of developing glaucoma were less in females (P = 0.04) and in patients with a higher standard of living index (P < 0.001).

Conclusion

One-third of the patients had glaucoma and another one-third were suspects. Secondary glaucomas are more common than primary/congenital glaucomas. A comprehensive eye evaluation is a must, especially in those with predisposing factors.

Juvenile-onset open-angle glaucoma - A clinical and genetic update

Juvenile-onset open-angle glaucoma (JOAG) is a subset of primary open-angle glaucoma that is diagnosed before 40 years of age. The disease may be familial or non-familial, with proportions varying among different populations. Myocilin mutations are the most commonly associated. JOAG is characterized by high intraocular pressures (IOP), with many patients needing surgery. The mean age at diagnosis is in the 3rd decade, with a male preponderance. Myopia is a common association. The pathophysiology underlying the disease is immaturity of the conventional outflow pathways, which may or may not be observed on gonioscopy and anterior segment optical coherence tomography. The unique optic nerve head features include large discs with deep, steep cupping associated with high IOP-induced damage. Progression rates among JOAG patients are comparable to adult primary glaucomas, but as the disease affects younger patients, the projected disability from this disease is higher. Early diagnosis, prompt management, and life-long monitoring play an important role in preventing disease progression. Gene-based therapies currently under investigation offer future hope.

A Prospective Study of Intraocular Pressure Spike and Failure After Gonioscopy-Assisted Transluminal Trabeculotomy in Juvenile Open-Angle Glaucoma: A Prospective Study of GATT in JOAG

PURPOSE

To identify risk factors for surgical failure after gonioscopy-assisted transluminal trabeculotomy (GATT) in juvenile open-angle glaucoma (JOAG).

DESIGN

Prospective, interventional case series.

METHODS

GATT was the initial surgery in 70 eyes of 70 patients with JOAG. Surgical success was defined as a postoperative intraocular pressure (IOP) of ≤21 mm Hg with at least a 20% reduction from preoperative IOP, with or without the use of antiglaucoma medication (qualified and complete success, respectively) at each postoperative visit. IOP spike was defined as IOP >30 mm Hg and an increase of at least 10 mm Hg from IOP before the spike, and then reduced to ≤21 mm Hg.

RESULTS

The median age at the time of surgery was 19.3 years (range, 4.9-37.5 years) with a visual field mean deviation of -17.4 ± 10.6 dB. Mean IOP decreased from 31.3 ± 9.5 mm Hg preoperatively to 15.8 ± 2.7 at 12 months postoperatively. The complete and qualified success rates were 74.3% and 91.4%, respectively. An IOP spike occurred in 52 eyes (74%), with a median spike duration of 3.5 days (range, 1-21 days). Longer duration of IOP spike (P = .009) and older age at the time of surgery (P = .025) were both associated with worse surgical outcomes. Advanced disease was associated with prolonged IOP spike (P = .007).

CONCLUSIONS

GATT provided excellent outcomes in patients with severe JOAG. Older age and longer duration of postoperative IOP spike are risk factors for failure. Severe cases are more likely to have longer durations of IOP spike. Frequent IOP monitoring during the early postoperative period is needed to detect IOP spikes in these patients.

Childhood and Early Onset Glaucoma Classification and Genetic Profile in a Large Australasian Disease Registry

PURPOSE

To report the relative frequencies of childhood and early onset glaucoma subtypes and their genetic findings in a large single cohort.

DESIGN

Retrospective clinical and molecular study.

PARTICIPANTS

All individuals with childhood glaucoma (diagnosed 0 to <18 years) and early onset glaucoma (diagnosed 18 to <40 years) referred to a national disease registry.

METHODS

We retrospectively reviewed the referrals of all individuals with glaucoma diagnosed at <40 years of age recruited to the Australian and New Zealand Registry of Advanced Glaucoma (ANZRAG). Subtypes of glaucoma were determined using the Childhood Glaucoma Research Network (CGRN) classification system. DNA extracted from blood or saliva samples underwent sequencing of genes associated with glaucoma.

MAIN OUTCOME MEASURES

The phenotype and genotype distribution of glaucoma diagnosed at <40 years of age.

RESULTS

A total of 290 individuals (533 eyes) with childhood glaucoma and 370 individuals (686 eyes) with early onset glaucoma were referred to the ANZRAG. Primary glaucoma was the most prevalent condition in both cohorts. In the childhood cohort, 57.6% of individuals (167/290, 303 eyes) had primary congenital glaucoma (PCG), and 19.3% (56/290, 109 eyes) had juvenile open-angle glaucoma. Juvenile open-angle glaucoma constituted 73.2% of the early onset glaucoma cohort (271/370, 513 eyes). Genetic testing in probands resulted in a diagnostic yield of 24.7% (125/506) and a reclassification of glaucoma subtype in 10.4% of probands (13/125). The highest molecular diagnostic rate was achieved in probands with glaucoma associated with nonacquired ocular anomalies (56.5%). Biallelic variants in CYP1B1 (n = 29, 23.2%) and heterozygous variants in MYOC (n = 24, 19.2%) and FOXC1 (n = 21, 16.8%) were most commonly reported among probands with a molecular diagnosis. Biallelic CYP1B1 variants were reported in twice as many female individuals as male individuals with PCG (66.7% vs. 33.3%, P = 0.02).

CONCLUSIONS

We report on the largest cohort of individuals with childhood and early onset glaucoma from Australasia using the CGRN classification. Primary glaucoma was most prevalent. Genetic diagnoses ascertained in 24.7% of probands supported clinical diagnoses and genetic counseling. International collaborative efforts are required to identify further genes because the majority of individuals still lack a clear molecular diagnosis.

The mutational spectrum of Myocilin gene among familial versus sporadic cases of Juvenile onset open angle glaucoma

PURPOSE

Juvenile onset primary open angle glaucoma (JOAG) is a rare disorder associated with high IOP and progressive optic neuropathy in patients diagnosed before the age of 40 years. While in some populations it has primarily an autosomal dominant pattern of inheritance, in others it occurs in a primarily sporadic form. The main aim of the study was to assess the relative prevalence of Myocilin (MYOC) mutations in familial versus sporadic cases of JOAG.

METHODS

We screened 92 unrelated (sporadic) JOAG patients, and 22 affected families (70 affected members and 36 unaffected) for variations in the MYOC gene. We also analyzed the clinical features associated with these variations.

RESULTS

Three coding sequence variants were identified as mutations causing JOAG. Four families segregated distinct mutations at Gly367Arg, and two families at Gln337Arg, while only two sporadic JOAG cases harbored MYOC mutations (Gly367Arg and Gln48His). The frequency of MYOC mutations in familial cases (27%) was significantly higher than in sporadic JOAG cases (2%); p = 0.001. A 90% penetrance for the Gly367Arg variant was seen by the age of 40 years in our patients. Characteristic allele signatures, indicative of specific founder effects, were not observed for the Gly367Arg mutation that was looked for in 12 patients among 2 geographically close families, which harbored this mutation.

CONCLUSION

Our data demonstrated that genetic screening for MYOC mutations should be focused toward cases with familial rather than sporadically occurring JOAG.

Comparison of Refractive Status and Anterior Segment Parameters of Juvenile Open-Angle Glaucoma and Normal Subjects

Objectives:

Our aim was to compare the refractive status and anterior segment parameters of patients with juvenile open-angle glaucoma (JOAG) and normal subjects.

Materials and Methods:

Twenty-five recently diagnosed cases of JOAG and 24 normal subjects were included in this prospective controlled clinical trial. Central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), axial length (AL), K1 and K2 keratometry, and white-to-white distance (WTW) measurements were performed with optical biometry (LenStar LS 900, Haag Streit Diagnostics). Spherical equivalent (SE) values and anterior segment parameters were statistically compared by chi-square, Kolmogorov- Smirnov, and independent samples t-tests.

Results:

The mean age of the 15 male and 10 female JOAG patients was 11.8±2.78 (8-18) years and the mean age of the 14 male and 10 female normal subjects was 11.58±3.04 (7-16) years (age: p=0.51; sex: p=0.18). Mean intraocular pressure in the JOAG group before treatment was 30.08±4.3 mmHg. The mean SE values of the JOAG and the control group were -1.94±1.86 (+2.35/-5.5) and -0.76±2.03 (+2.25/-4.85) diopters, respectively (p=0.048). JOAG patients had lower mean CCT values (p=0.016) and higher mean AL and ACD values (p=0.049 and p=0.016). There were no significant differences between the groups for LT, WTW, K1, or K2 (p=0.61; p=0.52; p=0.95; p=0.31 respectively).

Conclusion:

JOAG patients were found to be more myopic and have lower CCT and greater AL and ACD values than normal subjects. These anterior segment changes may be associated with myopia, which is common in JOAG.

Physiological function of myocilin and its role in the pathogenesis of glaucoma in the trabecular meshwork (Review)

Myocilin is highly expressed in the trabecular meshwork (TM), which plays an important role in the regulation of intraocular pressure (IOP). Myocilin abnormalities may cause dysfunction of the TM, potentially leading to increased IOP. High IOP is a well‑known primary risk factor for glaucoma. Myocilin mutations are common among glaucoma patients, and they are implicated in juvenile‑onset open‑angle glaucoma (JOAG) and adult‑onset primary open‑angle glaucoma (POAG). Aggregation of aberrant mutant myocilins is closely associated with glaucoma pathogenesis. The aim of the present review was to discuss the recent findings regarding the major physiological functions of myocilin, such as intra‑ and extracellular proteolytic processes. We also aimed to discuss the risk factors associated with myocilin and the development of glaucoma, such as misfolded/mutant myocilin, imbalance of myocilin and extracellular proteins, and instability of mutant myocilin associated with temperature. Finally, we further outlined certain issues that are yet to be resolved, which may represent the basis for future studies on the role of myocilin in glaucoma.