Correlation of postoperative axial length growth and intraocular pressure in congenital glaucoma--a retrospective study in trabeculotomy and goniotomy

Combined trabeculotomy-trabeculectomy for glaucoma after congenital cataract surgery: long-term results

OBJECTIVE

The aim of this study was to report on the long-term (>5 years) results of surgery for glaucoma after congenital cataract surgery.

DESIGN

Retrospective.

METHODS

A chart review was conducted of all children operated on for glaucoma after congenital cataract surgery in the Pediatric Ophthalmology Service of the Ophthalmology Department of Alexandria main University Hospital in Alexandria, Egypt, between 2005 and 2014 who completed 5 years of follow-up. Demographic, clinical, and operative data were retrieved from the medical records. Success was defined by stability and (or) reversal of optic nerve cupping in relation to presentation and, if this information was not available, by an intraocular pressure (IOP) less than the presenting IOP and less than 16 mm Hg with (true) or without (qualified) IOP-lowering therapy.

RESULTS

The records of 48 children were reviewed. Thirty-two eyes of 24 children had completed at least 5 years of follow-up and were included in the study. The mean age (±SD) of the study children was 11.6 ± 11.3 months (range, 3.2-52.0 months) at presentation, and the mean (±SD) follow-up was 105.5 ± 31.4 months (range, 60-156 months). Of 47 glaucoma surgical procedures in total, combined angle and filtering surgery with antimetabolite was the most common procedure performed (n = 30;63.8%). Annual success percentages from the fifth year onward to the thirteenth year were 69.6%, 68.8%, 77.8%, 50.0%, 71.4%, 60.0%, 50.0%, 83.3%, and 50.0%, respectively.

CONCLUSIONS

Surgery for glaucoma after congenital cataract surgery remains safe and successful for 13 years after surgery.

Prevalence, Associated Factors, and Inter-Eye Differences of Refractive Errors in a Population-Based Japanese Cohort: The Tohoku Medical Megabank Eye Study

PURPOSE

To investigate the prevalence, associated factors, and inter-eye differences of myopia and astigmatism in an adult Japanese population-based cohort.

METHODS

A total of 4282 participants from the Tohoku Medical Megabank Organization Eye Study (ToMMo Eye Study) underwent comprehensive ocular examinations as well as extensive physiological tests and a lifestyle questionnaire. The spherical equivalent (SE) and cylinder power were obtained as refractive parameters. The age- and gender-stratified prevalences of high myopia (SE < -5D), myopia (SE < -0.5D), hyperopia (SE > 0.5D), astigmatism (cylinder power < -0.5D), and anisometropia (SE difference >1D) were calculated. Multivariable analyses were performed to identify associated factors for refractive error (RE). Distribution and associated factors of the inter-eye difference in RE were also investigated.

RESULTS

The age-adjusted prevalence of high myopia, myopia, hyperopia, astigmatism, and anisometropia was 15.9%, 63.5%, 14.7%, 51.1%, and 14.7%, respectively. Both myopia and high myopia were more prevalent in the younger age group, while astigmatism was more prevalent in the older age group. Age, education, blood pressure, intraocular pressure, and corneal thickness are significantly associated with myopic refraction. Age, gender, intraocular pressure, and corneal thickness are correlated with astigmatism. Older age was associated with against-the-rule astigmatism. Older age, myopia, and longer education showed a significant correlation with large inter-eye differences in SERE.

CONCLUSIONS

This study demonstrated the high prevalence of myopia in young Japanese, which may be caused by a generational shift. This study also confirmed the influence of age and education on both the prevalence and inter-eye differences of RE.

Clinical Analysis of Pediatric Glaucoma in Central China

Purpose

We aimed to describe the characteristics, epidemiology, management, and outcomes of glaucoma in pediatric patients in central China.

Methods

This study retrospectively analyzed inpatients with pediatric glaucoma at Henan Provincial People's Hospital, Henan Eye Institute, and Henan Eye Hospital between 2017 and 2020.

Results

Overall, 239 cases (276 eyes) of pediatric glaucoma in patients, comprising 87 girls (36.40%) and 152 boys (63.60%) were analyzed. The mean age was 6.65 ± 4.46, and 2.93% of the patients had a family history of glaucoma. Primary congenital glaucoma (PCG) was the most common type of glaucoma, followed by traumatic glaucoma in 8.33% of the patients, which was considered secondary glaucoma. The most common signs and symptoms were elevated intraocular pressure (IOP) and eye pain. Trabeculotomy (Trab) and microcatheter-assisted 360° trabeculotomy (MAT) combined with Trab were the most commonly performed surgeries. The IOP of patients with PCG, juvenile open-angle glaucoma (JOAG), and secondary glaucoma were 15.27 ± 7.48 mmHg, 17.16 ± 10.05, and 18.65 ± 8.55, respectively, at the final follow up. The rate of re-operations in patients with PCG, JOAG, and secondary glaucoma were 9.15%, 6.78%, and 4.69%, respectively. The mean visual acuity of the eyes with PCG, JOAG, and secondary glaucoma was 0.79 ± 0.68, 0.51 ± 0.48, and 0.53 ± 0.50, respectively.

Conclusion

PCG, JOAG, and traumatic glaucoma were the most prevalent subtypes in patients with pediatric glaucoma in central China. Trab and MAT combined with Trab were the most common interventions used in this study. Pediatric amblyopia might require full attention during the entire treatment, especially after glaucoma surgery. Effective preventive measures and more public education on glaucoma prevention and the importance of early diagnosis and treatment is necessary.

Results of childhood glaucoma surgery over a long-term period

PURPOSE

To evaluate long-term results of glaucoma surgery in newborn and infants with glaucoma.

METHODS

Seventy-nine eyes of 52 children (age: 3 weeks-15.3 years) with primary congenital or secondary glaucoma treated between 2015 and 2017 were included. The median follow-up time was 3.9 years. Conventional probe trabeculotomy, 360° catheter-assisted trabeculotomy, filtering and cyclodestructive surgery were compared. Strict criteria for surgical success were applied: Complete surgical success (IOP below target IOP, no further surgery) and incomplete surgical success (additional surgery allowed) were analyzed, and IOP at baseline and last follow-up was compared.

RESULTS

Intraocular pressure (IOP) was significantly reduced in primary congenital (preoperative IOP: 27.8 ± 7.5 mmHg vs. postoperative IOP: 14.2 ± 4.5 mmHg) and secondary glaucoma (preoperative IOP: 29.2 ± 9.1 mmHg vs. postoperative IOP: 16.6 ± 4.7 mmHg). 90% of all eyes reached target IOP with or without medication allowing for additional surgeries. As first surgery, 360° catheter-assisted trabeculotomy had a tendency to higher surgical success than other surgical approaches, while cyclodestructive procedures had lowest.

CONCLUSIONS

We found very promising surgical results in our childhood glaucoma patient group. Surgical success in both congenital and secondary glaucoma was high.

Twenty-Years of Experience in Childhood Glaucoma Surgery

To quantify the results of childhood glaucoma treatment over time in a cohort of children with different types of childhood glaucoma. A retrospective cohort study of consecutive cases involving children with primary congenital glaucoma, primary juvenile, and secondary juvenile glaucoma at the Childhood Glaucoma Center, University Medical Center Mainz, Germany from 1995 to 2015 was conducted. The main outcome measure was the long-term development of intraocular pressure. Further parameters such as surgical success, refraction, corneal diameter, axial length, and surgical procedure in children with different types of childhood glaucoma were evaluated. Surgical success was defined as IOP < 21 mmHg in eyes without a need for further intervention for pressure reduction. A total of 93 glaucomatous eyes of 61 childhood glaucoma patients with a mean age of 3.7 ± 5.1 years were included. The overall mean intraocular pressure at first visit was 32.8 ± 10.2 mmHg and decreased to 15.5 ± 7.3 mmHg at the last visit. In the median follow-up time of 78.2 months, 271 surgical interventions were performed (130 of these were cyclophotocoagulations). Many (61.9%) of the eyes that underwent surgery achieved complete surgical success without additional medication. Qualified surgical success (with or without additional medication) was reached by 84.5% of the eyes.

Lowering Intraocular Pressure: A Potential Approach for Controlling High Myopia Progression

High myopia is among the most common causes of vision impairment, and it is mainly characterized by abnormal elongation of the axial length, leading to pathologic changes in the ocular structures. Owing to the close relationship between high myopia and glaucoma, the association between intraocular pressure (IOP) and high myopia progression has garnered attention. However, whether lowering IOP can retard the progression of high myopia is unclear. On reviewing previous studies, we suggest that lowering IOP plays a role in progressive axial length elongation in high myopia, particularly in pathologic myopia, wherein the sclera is more remodeled. Based on the responses of the ocular layers, we further proposed the potential mechanisms. For the sclera, lowering the IOP could inhibit the activation of scleral fibroblasts and then reduce scleral remodeling, and a decrease in the scleral distending force would retard the ocular expansion like a balloon. For the choroid, lowering IOP results in an increase in choroidal blood perfusion, thereby reducing scleral hypoxia and slowing down scleral remodeling. The final effect of these pathways is slowing axial elongation and the development of scleral staphyloma. Further animal and clinical studies regarding high myopia with varied degree of IOP and the changes of choroid and sclera during IOP fluctuation in high myopia are needed to verify the role of IOP in the pathogenesis and progression of high myopia. It is hoped that this may lead to the development of a prospective treatment option to prevent and control high myopia progression.

Comparison of ocular axis and corneal diameter between entropion and non-entropion eyes in children with congenital glaucoma

BACKGROUND

Children with congenital glaucoma are often accompanied by acquired epiblepharon in the lower eyelid, which causes entropion of the lower eyelid and damages the cornea.

AIM

To infer the possible causes of lower eyelid entropion by comparing the difference of ocular axis and corneal diameter between inverted and non-inverted ciliary eyes in children with congenital glaucoma.

METHODS

A total of 15 patients (11 males and 4 females) diagnosed with congenital glaucoma between July 2016 and January 2019 at Tongren Hospital were included. Five patients had bilateral glaucoma, and ten had unilateral glaucoma. Each patient had only one eye with lower eyelid entropion which is associated with congenital glaucoma. All the patients had no entropion in another eye. The clinical data were collected. Main outcome measures were the ocular axis and corneal diameter.

RESULTS

The average age of the 15 patients was 1.85 ± 0.49 years. Paired t-test showed that the average ocular axis of congenital glaucoma eyes with lower eyelid entropion (24.86 ± 3.44 mm) was significantly longer than that of congenital glaucoma eyes without lower eyelid entropion (20.79 ± 1.34 mm; P < 0.001). The average corneal diameter of congenital glaucoma eyes with lower eyelid entropion (13.61 ± 0.88 mm) was also significantly greater than that of congenital glaucoma eyes without lower eyelid entropion (11.63 ± 0.48; P < 0.001).

CONCLUSION

The rapid growth of the ocular axis and corneal diameter may be the main cause of congenital glaucoma with acquired lower eyelid entropion. Therefore, children with poor control of intraocular pressure and excessive growth of ocular axis and corneal diameter must be observed for the existence of acquired epiblepharon.

Meta-analysis of ocular axial length in newborns and infants up to 3 years of age

In pediatric ophthalmology it is often necessary to obtain axial length in young children. For children older than 3 years, noncontact biometry can be used. For younger children this is usually not an option, and the clinician needs to rely on other imaging modalities. Depicted data curves in textbooks elaborate on few studies and limited number of subjects. The existing literature regarding normal axial length for preterm infants and term newborns is summarized and critically appraised for number of subjects, relevance, measurement method and error, gender and retinopathy of prematurity. We obtained axial length measurements for a total number of 6,575 eyes in 27 papers published from 1964 to 2018 (9 papers with 2,272 eyes for preterm children, 24 papers with 4,303 eyes for term children). Initially, axial length increases rapidly: from a mean 5.1-16.2 mm in week 12 to week 37 gestational age. From 38 weeks, growth rate decreases from 16.2 mm to a mean of 21.8 mm at 3 years old. Male infants have a larger average axial length than females at birth; the difference is 0.24 mm (95%CI: 0.15-0.33, P < 0.001). We present a useful growth curve and formula that may serve as a reference for diagnosing abnormal growth.

Kahook Dual Blade Ab-interno Trabeculectomy Compared With Conventional Goniotomy in the Treatment of Primary Congenital Glaucoma: 1-Year Results

INTRODUCTION

Kahook dual blade (KDB) removes a strip of the trabecular meshwork from the angle, which may make it superior to simple goniotomy in treating the angle anomaly in primary congenital glaucoma (PCG). This prospective study compares KDB ab-interno trabeculectomy to conventional goniotomy in PCG.

METHODS

Forty-two eyes of 29 patients with PCG underwent ab-interno trabeculectomy using a KDB or conventional goniotomy using a 25-G irrigating needle, targeting 100 to 120 degrees of the nasal iridocorneal angle. Patients were seen at 1, 3, 6, and 12 months postoperatively. Success was defined as intraocular pressure (IOP) ≤21 mm Hg at 1-year follow-up visit, with no evidence of glaucoma progression.

RESULTS

The KDB group included 21 eyes of patients with a median age of 6 months (interquartile range: 4 to 8.5 mo) and the goniotomy group included 21 eyes of patients with a median age of 5 months (interquartile range: 3 to 9.5 mo). There was a significant reduction in IOP in both groups at all follow-up visits. The reduction in the number of glaucoma medications was significant at 1, 3, and 6 months postoperatively in the KDB group, and at 1 month in the goniotomy group. There was no significant difference in IOP or glaucoma medications between both groups at any follow-up visit. Success was achieved in 12 eyes (57.1%) in each group, with no eyes developing any serious complications.

CONCLUSION

One-year results show that KDB ab-interno trabeculectomy is at least as effective as goniotomy in the treatment of PCG. Eyes with bilateral glaucoma had a tendency to fail both procedures.

Retrospective analysis of paediatric glaucoma at a tertiary referral centre in Hong Kong

PURPOSE

To evaluate the epidemiological features, clinical interventions, and outcomes of paediatric glaucoma in Hong Kong.

STUDY DESIGN

Retrospective chart review.

METHODS

Clinical data from the medical records of all patients under 18 years of age diagnosed with glaucoma from January 2008 to December 2017 at a university-affiliated, tertiary referral centre were collected. The patients' demographics, etiological distribution, clinical interventions, and outcomes were analysed.

RESULTS

A total of 33 subjects (53 eyes) were identified, 30 (49 eyes) of whom were Chinese. Primary glaucoma accounted for 21.2% of subjects, while 78.8% were diagnosed with secondary glaucoma. The most common subtype was juvenile-onset open angle glaucoma, followed by Sturge-Weber Syndrome related glaucoma. The most commonly performed surgical interventions were tube-shunt surgery (Ahmed Glaucoma Valve) and transscleral cyclophotocoagulation. Most eyes had significant reduction in intraocular pressure after medical or surgical intervention, but deterioration of visual acuity remained common.

CONCLUSION

Most cases of childhood glaucoma in Hong Kong are secondary rather than primary, similar to other regions with low incidence of parental consanguinity. The large proportion of secondary glaucoma which generally has poorer prognosis, is reflected by the frequency of multiple surgery, and a high incidence of visual deterioration despite significant intraocular pressure reduction in most eyes.

The relationship between axial length, age and intraocular pressure in children with primary congenital glaucoma

Whilst axial length (AxL) from ultrasound examination is a useful clinical parameter for monitoring progression in younger children with glaucoma, distinguishing AxL changes due to raised intraocular pressure (IOP) from age is often challenging. Existing normograms have included a limited number of children with glaucoma. The aim of this study was to evaluate the relationship between AxL with age and IOP in children with primary congenital glaucoma (PCG) and develop a model for expected AxL increase with age. All children (n = 208; 397 eyes) with PCG who attended our tertiary eye care facility from June 2014 and July 2018 and had AxL and IOP measurements were included. The relationship of AxL with age and IOP was studied by applying a LOWESS fit and then mixed effects models. In the final model, age was the most significant factor influencing the growth of AxL (coefficient age 3.14[95% CI 2.91–3.35, p < 0.001], coefficient age² − 0.53[95% CI, − 0.59 to − 0.47, p < 0.001]), and this association was influenced by the interaction of IOP with sex (p = 0.098 for girls relative to boys), the number of antiglaucoma medications (AGM [p < 0.001 for ≥ 3 AGM]) and glaucoma surgery (p = 0.015). This model enabled us to derive predicted values for clinical use in children with PCG to predict those with progressive glaucoma.

Surgical interventions for primary congenital glaucoma

BACKGROUND

Primary congenital glaucoma (PCG) is an optic neuropathy with high intraocular pressure (IOP) that manifests within the first few years of a child's life and is not associated with other systemic or ocular abnormalities. PCG results in considerable morbidity even in high-income countries.

OBJECTIVES

To compare the effectiveness and safety of different surgical techniques for PCG.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2020, Issue 4); Ovid MEDLINE; Embase.com; PubMed; metaRegister of Controlled Trials (mRCT) (last searched 23 June 2014); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search. We last searched the electronic databases on 27 April 2020.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs comparing different surgical interventions in children under five years of age with PCG.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology.

MAIN RESULTS

We included 16 trials (13 RCTs and three quasi-RCTs) with 587 eyes in 446 children. Eleven (69%) trials were conducted in Egypt and the Middle East, three in India, and two in the USA. All included trials involved children younger than five years of age, with follow-up ranging from six to 80 months. The interventions compared varied across trials. Three trials (on 68 children) compared combined trabeculotomy and trabeculectomy (CTT) with trabeculotomy. Meta-analysis of these trials suggests there may be little to no evidence of a difference between groups in mean IOP (mean difference (MD) 0.27 mmHg, 95% confidence interval (CI) -0.74 to 1.29; 88 eyes; 2 studies) and surgical success (risk ratio (RR) 1.01, 95% CI 0.90 to 1.14; 102 eyes; 3 studies) at one year postoperatively. We assessed the certainty of evidence as very low for these outcomes, downgrading for risk of bias (-1) and imprecision (-2). Hyphema was the most common adverse outcome in both groups (no meta-analysis due to considerable heterogeneity; I² = 83%). Two trials (on 39 children) compared viscotrabeculotomy to conventional trabeculotomy. Meta-analysis of 42 eyes suggests there is no evidence of between groups difference in mean IOP (MD -1.64, 95% CI -5.94 to 2.66) and surgical success (RR 1.11, 95% CI 0.70 to 1.78) at six months postoperatively. We assessed the certainty of evidence as very low, downgrading for risk of bias and imprecision due to small sample size. Hyphema was the most common adverse outcome (38% in viscotrabeculotomy and 28% in conventional trabeculotomy), with no evidence of difference difference (RR 1.33, 95% CI 0.63 to 2.83). Two trials (on 95 children) compared microcatheter-assisted 360-degree circumferential trabeculotomy to conventional trabeculotomy. Meta-analysis of two trials suggests that mean IOP may be lower in the microcatheter group at six months (MD -2.44, 95% CI -3.69 to -1.19; 100 eyes) and at 12 months (MD -1.77, 95% CI -2.92 to -0.63; 99 eyes); and surgical success was more likely to be achieved in the microcatheter group compared to the conventional trabeculotomy group (RR 1.59, 95% CI 1.14 to 2.21; 60 eyes; 1 trial at 6 months; RR 1.54, 95% CI 1.20 to 1.97; 99 eyes; 2 trials at 12 months). We assessed the certainty of evidence for these outcomes as moderate due to small sample size. Hyphema was the most common adverse outcome (40% in the microcatheter group and 17% in the conventional trabeculotomy group), with greater likelihood of occurring in the microcatheter group (RR 2.25, 95% CI 1.25 to 4.04); the evidence was of moderate certainty due to small sample size (-1). Of the nine remaining trials, no two trials compared the same two surgical interventions: one trial compared CTT versus CTT with sclerectomy; three trials compared various suturing techniques and adjuvant use including mitomycin C, collagen implant in CTT; one trial compared CTT versus Ahmed valve implant in previously failed surgeries; one trial compared CTT with trabeculectomy; one trial compared trabeculotomy to goniotomy; and two trials compared different types of goniotomy. No trials reported quality of life or economic data. Many of the included trials had limitations in study design, implementation, and reporting, therefore the reliability and applicability of the evidence remains unclear.

AUTHORS' CONCLUSIONS

The evidence suggests that there may be little to no evidence of difference between CTT and routine conventional trabeculotomy, or between viscotrabeculotomy and routine conventional trabeculotomy. A 360-degree circumferential trabeculotomy may show greater surgical success than conventional trabeculotomy. Considering the rarity of the disease, future research would benefit from a multicenter, possibly international trial, involving parents of children with PCG and with a follow-up of at least one year.

Surgical Outcomes in Children With Primary Congenital Glaucoma: An Eight-Year Experience

Background

Primary congenital glaucoma (PCG) is a congenital anomaly arising from an unusual development of the filtration angle, causing a remarkable rise in intraocular pressure (IOP) that is irrelevant to other ocular or systemic deformities.

Purpose

The aim of the current study was to evaluate the surgical outcome in PCG patients between 2011 and February 2019.

Methods

This was a retrospective study of PCG patients who underwent trabeculotomy, trabeculectomy, deep sclerectomy, Ahmed valve, and/or cyclophotocoagulation (CPC) at a tertiary hospital. The IOP must be equal or less than 21 mmHg with or without medication to be designated a successful surgery.

Results

A total of 80 eyes (41 patients) were included in the study, with a slight male predominance of 65.9%. At presentation, the most reported age group was under 30 days (46.3%). Moreover, deep sclerotomy was the most common procedure, followed by CPC, which were performed in 48 (58.5%) and 18 (21.9%) eyes, respectively. In the overall group, the mean initial IOP was 23.65±8.52 mmHg, while the mean IOP was 16.73±8.56 mmHg at final follow-ups (p < 0.001), with a 46% reduction. The mean axial length showed a slight progression from 21.11±2.58 at the initial visit to 22.92±3.57 mm at the last follow-up (p<0.001). However, the mean horizontal diameter increased from 12.63±1.83 mm at the initial visit to 13.31±1.13 mm at the final visit (p=0.004).

Conclusion 

An excellent IOP reduction could be accomplished in the majority of eyes. Deep sclerectomy can effectively reduce IOP in PCG without the occurrences of serious complications that are commonly seen after other procedures like trabeculectomy or trabeculotomy.

Combined Viscodilation of Schlemm's Canal and Collector Channels and 360° Ab-Interno Trabeculotomy for Congenital Glaucoma Associated with Sturge-Weber Syndrome

Purpose

This case report demonstrates the potential role of the OMNI surgical system in the surgical management of congenital glaucoma.

Patients and Methods

The case was a 4-month-old full-term, otherwise healthy female infant with cutaneous hemangiomas of both upper lids, corneal edema in the right eye (RE) and IOP > 30 mmHg. Sturge-Weber syndrome (SWS) was diagnosed. The RE was surgically treated with ab-interno circumferential viscodilation and trabeculotomy.

Results

Through 10 months of follow-up, intraocular pressure was adequately controlled without the need for adjunctive medical therapy.

Conclusion

Given its advantages over other angle surgery techniques, this procedure's role in treating glaucomas of childhood warrants further evaluation.

Influence of Axial Length on Intraocular Pressure Measurement With Three Tonometers in Childhood Glaucoma

PURPOSE

To determine the agreement between intraocular pressure (IOP) measurements obtained using the handheld version of the Goldmann applanation (Perkins; Clement-Clarke, Haag-Streit, Harlow, United Kingdom), rebound Icare-Pro (Icare, Tiolat Oy, Helsinki, Finland), and Tonopen XL (Reichert Inc., Depew, NY) tonometers in children with childhood glaucoma and to identify factors that may affect those measurements.

METHODS

Ninety-one eyes of 46 children with early-onset childhood glaucoma were included in this cross-sectional study in which IOP, ocular axial length, anterior chamber depth, lens thickness, vitreous length, and central corneal thickness measurements were obtained under general anesthesia. Agreement between tonometers was evaluated using intraclass correlation coefficients (ICCs) and the Bland-Altman method. The influence of ocular biometric parameters and central corneal thickness on IOP measurements was analyzed using multiple linear regression analysis.

RESULTS

The mean age of the children in the current study was 29.1 months (range: 13 to 31 months). The Icare-Pro and Tonopen XL overestimated IOP measurements compared to the Perkins tonometer (Icare-Pro-Perkins mean IOP difference: 2.2 ± 3.4 mm Hg, P < .0001, 95% confidence interval [CI]: 1.5 to 2.9 vs Tonopen XL-Perkins mean IOP difference: 6.7 ± 7.1 mm Hg, P < .0001, 95% CI: 5.2 to 8.2). The Icare-Pro showed greater agreement with the Perkins tonometer than the Tonopen XL (ICC: 0.789, 95% CI: 0.697 to 0.856, P < .0001 vs 0.453, 95% CI: 0.272 to 0.603, P < .0001). Ocular axial length affected IOP measurements the most, finding increased impact on Tonopen XL (slope: 0.086, 95% CI: 0.013 to 0.16, P = .022 vs 0.997, 95% CI: 0.369 to 1.625, P = .002 vs 1.571, 95% CI: 0.541 to 2.602, P < .0001 for Perkins, Icare-Pro, and Tonopen XL IOP measurements, respectively).

CONCLUSIONS

Ocular axial length affects IOP measured by the Perkins, Icare-Pro, and Tonopen XL devices in patients with childhood glaucoma. The Icare-Pro shows more agreement with the Perkins tonometer than the Tonopen XL; therefore, it seems to be a more suitable option for these patients. [J Pediatr Ophthalmol Strabismus. 2020;57(1):27-32.].

Evaluation of changes in axial length after congenital cataract surgery

PURPOSE

To investigate the relationship between lens status and axial length (AL) in patients operated for unilateral and bilateral congenital cataract.

SETTING

Yüzüncü Yıl University, Ophthalmology Clinic, Van, Turkey.

DESIGN

Retrospective study.

METHODS

Records of patients who underwent surgery for unilateral or bilateral congenital cataract were analyzed. The patients were separated into three groups: bilateral aphakic, bilateral pseudophakic, and unilateral. The unilateral group was subdivided into the operated cataract eyes (unilateral aphakic and unilateral pseudophakic) and unoperated fellow phakic eyes. The patients' age at surgery, follow-up time, preoperative and postoperative AL measurements, change in AL, and monthly growth rate were evaluated.

RESULTS

The bilateral aphakic group included 40 eyes of 20 patients, the bilateral pseudophakic group included 103 eyes of 54 patients, and the unilateral group included 40 eyes of 20 patients. The mean age at time of surgery in these groups was 8.17 months ± 10.65 (SD), 42.47 ± 43.81 months, and 42.47 ± 43.81 months, respectively. There were no significant differences in preoperative AL, postoperative AL, change in AL, or monthly growth rate between the aphakic and fellow phakic eyes in the unilateral group (P > .05). There were also no significant differences between unilateral pseudophakic eyes and fellow phakic eyes in the unilateral group with respect to preoperative AL or change in AL, but there were significant differences in final AL and monthly growth rate (P < .05).

CONCLUSIONS

Various factors can affect axial elongation. The monthly growth rate was lower in pseudophakic eyes compared with phakic eyes. Experimental studies are required to understand the mechanism underlying this effect.

Corneal profile in primary congenital glaucoma

PURPOSE

To investigate biomechanical and ultrastructural corneal parameters and ocular biometrics in the affected eyes of patients with unilateral primary congenital glaucoma (PCG) as compared to unaffected fellow eyes and age-matched healthy controls.

METHODS

A total of 12 patients with treated unilateral PCG and 10 normal subjects were evaluated. LENSTAR was performed to determine biometric parameters; the ocular response analyser was employed to determine biomechanical properties and slit-scanning confocal microscopy was used for evaluation of corneal ultrastucture.

RESULTS

Axial length was significantly higher and mean keratometry in affected eyes was significantly flatter in affected eyes as compared to fellow eyes and normal controls (p < 0.05), and a negative correlation was present between axial length and mean keratometry (p < 0.05). Mean aqueous depth and anterior chamber depth were increased in affected eyes as compared to fellow eyes and normal controls (p < 0.05). There was no significant difference in central corneal thickness (CCT) among affected eyes, fellow eyes and normal controls. Corneal hysteresis (CH) was significantly reduced in affected eyes (p < 0.05) and corneal resistance factor (CRF) was also reduced in the affected eyes as compared to fellow eyes and normal controls, although not statistically significant. Mean endothelial cell density was reduced in the affected eyes compared to fellow eyes and normal controls (p < 0.05).

CONCLUSION

Corneal biometrics, biomechanical parameters and ultrastructural features are altered in eyes affected with PCG despite clinically normal and clear corneas. These findings should be considered in the preoperative assessment of intraocular or corneal surgery in these patients.

Surgical Outcomes of Trabeculotomy in Newborns with Primary Congenital Glaucoma

Background:

Early surgical intervention is required for the primary congenital glaucoma (PCG). There are currently few reports on the surgical outcomes in infants with PCG. This study aimed to evaluate the efficacy and safety of trabeculotomy and the postoperative visual outcomes in Chinese newborns with PCG within 4 weeks of birth.

Methods:

A total of 21 eyes of 12 patients with PCG who underwent primary trabeculotomy within 4 weeks of birth were retrospectively studied. Preoperative and postoperative intraocular pressure (IOP), corneal clarity and diameter, axial length and optic disc cupping, visual acuity and postoperative refractive error, success rates, and complications were evaluated. Kaplan-Meier survival analysis was applied to evaluate the success rates.

Results:

The mean follow-up time was 46.9 ± 34.4 months (range: 12–122 months). The postoperative IOP was significantly lower than the preoperative IOP at all of the follow-up visits (P < 0.001). The complete success rates for all eyes at 1, 2, 3, and 5 years postoperatively were 90.5%, 85.7%, 85.7%, and 85.7%, respectively. The IOPs of the three patients who needed antiglaucomatous medications postoperatively were also well controlled. At the last visit, the cornea became clear, and the cup-to-disc ratio decreased significantly (P = 0.01) although the horizontal corneal diameter did not change significantly (P = 0.11). Visual acuities were able to be recorded in eight eyes at the last visit, among which six eyes had a best-corrected visual acuity of 20/40 or better. There were no severe intraoperative or postoperative complications.

Conclusions:

Trabeculotomy proves to be a safe and effective treatment in reducing IOP in this group of Chinese newborns with PCG. The outcomes of vision function were satisfactory in most of the patients.

Epiblepharon in congenital glaucoma: case-control study

BACKGROUND/AIMS

To assess the prevalence, clinical features and risk factors of lower lid epiblepharon among patients with congenital glaucoma.

METHODS

Cross-sectional, observational, case-control study. Patients diagnosed with congenital glaucoma between August 1999 and November 2014 were included. Demographic and clinical characteristic data were collected. Age-matched normal controls were recruited form general population. Main outcome measures were the prevalence, laterality and factors associated with epiblepharon in patients with congenital glaucoma.

RESULTS

The prevalence of lower lid epiblepharon was higher in patients with congenital glaucoma compared with control group (40.7% vs 13.3%, p<0.001). Unilateral epiblepharon was only shown in patients with congenital glaucoma (47.8% vs 0.0%, p<0.001). Multivariate analysis revealed that high intraocular pressure (IOP) at glaucoma diagnosis (OR=1.122), presence of corneal erosion (OR=82.664) and presence of buphthalmos (OR=12.600) were significantly associated with the presence of lower lid epiblepharon. In addition, unilateral epiblepharon was associated with unilateral buphthalmos and unilateral glaucoma (OR of 49.849 and 7.338, respectively).

CONCLUSIONS

The prevalence of epiblepharon was higher in patients with congenital glaucoma compared with age-matched general population. In patients with congenital glaucoma, epiblepharon was associated with corneal erosions. In addition, buphthalmos and initial high IOP were associated with the development of lower lid epiblepharon. More importantly, unilateral buphthalmos was also significantly associated with unilateral epiblepharon. Therefore, in patients with congenital glaucoma, presence of epiblepharon should be evaluated especially in patients accompanying buphthalmos or corneal erosion.

PERIPHERAL RETINAL DEGENERATIONS AND RHEGMATOGENOUS DETACHMENT IN PRIMARY CONGENITAL GLAUCOMA

BACKGROUND

To determine the prevalence of peripheral retinal degenerations (PRD) and rhegmatogenous retinal detachment in patients with primary congenital glaucoma (PCG).

METHODS

Records of all patients with PCG operated from year 2000 onwards were evaluated to look for the prevalence of rhegmatogenous retinal detachment. Of these, those children who were old enough to cooperate and had sufficient medial clarity were screened with an indirect ophthalmoscopy in a cross-sectional evaluation from 2010 to 2014. Peripheral retina was examined, and prevalence of PRD was estimated in this subset. For statistical purposes, only one eye of each patient was considered in this cross-sectional analysis.

RESULTS

Of the 310 eyes (180 patients with PCG) operated from the year 2000 onwards, a rhegmatogenous retinal detachment was noted in 13 eyes (4%). Mean axial length of these eyes was 26.3 ± 3.2 mm (range, 19.8-34.7 mm). Among the eyes screened for PRD (n = 60), prevalence of pathologic PRD (lattices with/without atrophic holes and isolated holes/tears) was 15%. The average follow-up between glaucoma filtering surgery and the date of last examination was 8.55 ± 3.98 years (range, 5-20 years) in this subset. Mean axial length was significantly greater in eyes with pathologic PRD than in those without (28.1 ± 3.3 mm vs. 25.8 ± 2.6 mm; P = 0.01). For axial length ≥ 26 mm, the odds of having a pathologic PRD were 14.4 times more than those with axial length < 26 mm (P < 0.001; 95% confidence interval, 1.7-120.5).

CONCLUSION

Prevalence of PRD among eyes with PCG is high. Peripheral retinal screening should be performed in eyes with PCG, especially those with axial lengths ≥ 26 mm.

The Role of Genetic Ancestry in Brazilian Patients With Primary Congenital Glaucoma

PURPOSE

The relationship between clinical data and genetic ancestry in Brazilian patients with primary congenital glaucoma (PCG) was studied.

PATIENTS AND METHODS

Thirty patients with PCG and 60 unrelated controls underwent a complete ophthalmological examination. The PCG inclusion criterion was prior surgery with a minimum follow-up of 6 months after the last surgical procedure. Clinical data were recorded and DNA from each individual was extracted and genotyped for a panel of 40 validated ancestry-informative insertion-deletion DNA polymorphisms (indels).

RESULTS

Eighteen (60%) children had bilateral disease and 16 (53.3%) were male. The mean age at diagnosis was 6.3 months and surgical follow-up time varied from 8 to 85 months. For the PCG group, the proportion of Europeans, Africans, and Amerindians was 0.784±0.044 (mean±SEM), 0.149±0.035, and 0.067±0.023, respectively, whereas for the control group was 0.730±0.048, 0.132±0.034, and 0.138±0.032, respectively. An increased proportion of African indels was associated with worse surgical prognosis (P=0.036). There was also a statistically significant (P<0.05) positive correlation between axial length and African component (initial: R=0.625; final: R=0.567).

CONCLUSIONS

An increased proportion of African indels was associated with worse prognosis for PCG in a mixed population. Genetic ancestry markers may be helpful in assessing risk factors for surgical outcomes in PCG. Further studies are needed to unveil the role of ancestry in heterogeneous populations such as Brazilians with PCG.

Pediatric Glaucoma: A Literature's Review and Analysis of Surgical Results

The purpose of this paper is to review the surgical options available for the management of pediatric glaucoma, to evaluate their advantages and disadvantages together with their long-term efficacy, all with the intent to give guidelines to physicians on which elements are to be considered when taking a surgical decision. Currently there is a range of surgical procedures that are being used for the management of pediatric glaucoma. Within these, some are completely new approaches, while others are improvements of the more traditional procedures. Throughout this vast range of surgical options, angle surgery remains the first choice in mild cases and both goniotomy and trabeculotomy have good success rates. Trabeculectomy with or without mitomycin C (MMC) is preferred in refractory cases, in aphakic eyes, and in older children. GDIs have a good success rate in aphakic eyes. Nonpenetrating deep sclerectomy is still rarely used; nevertheless the results of ongoing studies are encouraging. The different clinical situations should always be weighed against the risks associated with the procedures for the individual patients. Glaucomatous progression can occur many years after its stabilization and at any time during the follow-up period; for this reason life-long assessment is necessary.

Surgical interventions for primary congenital glaucoma

BACKGROUND

Primary congenital glaucoma (PCG) manifests within the first few years of a child's life and is not associated with any other systemic or ocular abnormalities. PCG results in considerable morbidity even in developed countries. Several surgical techniques for treating this condition, and lowering the intraocular pressure (IOP) associated with it, have been described.

OBJECTIVES

To compare the effectiveness and safety of different surgical techniques for PCG.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2014, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), (January 1982 to June 2014), PubMed (January 1946 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 23 June 2014.

SELECTION CRITERIA

We included all randomized and quasi-randomized trials in which different types of surgical interventions were compared in children under five years of age with PCG.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures specified by The Cochrane Collaboration.

MAIN RESULTS

We included a total of six trials (four randomized and two quasi-randomized) with 102 eyes in 61 children. Two trials were conducted in the USA and one trial each in Egypt, Israel, Lebanon and Saudi Arabia. All trials included children aged younger than one year when diagnosed with PCG, and followed them for periods ranging from six months to five years.No two trials compared the same pair of surgical interventions, so we did not perform any meta-analysis. One trial compared trabeculotomy versus goniotomy; a second trial compared combined trabeculectomy-trabeculotomy with mitomycin C versus trabeculectomy-trabeculotomy with mitomycin C and deep sclerectomy; a third trial compared combined trabeculotomy-trabeculectomy versus trabeculotomy; a fourth trial compared one goniotomy versus two goniotomies; a fifth trial compared trabeculotomy versus viscocanalostomy; and the sixth trial compared surgical goniotomy versus neodymium-YAG laser goniotomy. For IOP change and surgical success (defined by IOP achieved), none of the trials reported a difference between pairs of surgical techniques. However, due to the limited sample sizes for all trials (average of 10 children per trial), the evidence as to whether a particular surgical technique is effective and which surgical technique is better still remains uncertain. Adverse events, such as choroidal detachment, shallow anterior chamber and hyphema, were reported from four trials. None of the trials reported quality of life or economic data.These trials were neither designed nor reported well overall. Two trials were quasi-randomized trials and judged to have high risk of selection bias; four trials were at unclear or high risk for performance bias and detection bias; and we judged one trial to have high risk of attrition bias due to high proportions of losses to follow-up. Due to poor study design and reporting, the reliability and applicability of evidence remain unclear.

AUTHORS' CONCLUSIONS

No conclusions could be drawn from the trials included in this review due to paucity of data. More research is needed to determine which of the many surgeries performed for PCG are effective.

Effect of intraocular pressure control on central corneal thickness, horizontal corneal diameter, and axial length in primary congenital glaucoma

PURPOSE

To assess the effect of intraocular pressure (IOP) control on central corneal thickness (CCT), horizontal corneal diameter (HCD), and axial length (AL) in primary congenital glaucoma (PCG).

METHODS

The medical records of children under 10 years of age surgically treated for PCG from 2003 to 2012 were retrospectively reviewed to identify patients with IOP of ≤12 mm Hg with a minimum of 6 months' follow-up. Pre- and post-treatment IOP, CCT, HCD, and AL values were correlated and compared with those of healthy age-matched controls.

RESULTS

A total of 131 controls and 20 patients (12 bilateral; 8 unilateral) were included. Mean follow-up was 32.4 months. In 24 eyes IOP was controlled by 1 trabeculotomy, with 6 eyes requiring antiglaucoma medication; in 5 eyes, by 2 trabeculotomies, without medication; and in 3 eyes, by 2 trabeculotomies plus 1 with mitomycin-C and 2 eyes requiring antiglaucomatous medication. The mean IOP was 15.69 ± 5.31 mm Hg preoperatively and 6.16 ± 2.42 mm Hg at final follow-up. Mean pre- and postoperative CCT values were, respectively, 614.38 ± 89.41 μm and 548.56 ± 63.12 μm; HCD, 13.45 ± 1.00 mm and 13.98 ± 1.01 mm, respectively; AL, 24.57 ± 2.71 mm and 25.37 ± 2.66 mm, respectively. All differences were statistically significant (P ≤ 0.002). In 40% of patients, post-treatment CCT values were comparable to those of controls; in 6.2%, HCD measurements; and in 26%, AL measurements. Pre- and post-treatment measurements were positively correlated (P ≤ 0.009).

CONCLUSIONS

Controlling IOP had a positive effect on the CCT, HCD, and AL in patients with congenital glaucoma.

Current surgical options for the management of pediatric glaucoma

Currently, there are numerous choices for the treatment of pediatric glaucoma depending on the type of glaucoma, the age of the patient, and other particularities of the condition discussed in this review. Traditionally, goniotomy and trabeculotomy ab externo have been the preferred choices of treatment for congenital glaucoma, and a variety of adult procedures adapted to children have been utilized for other types of pediatric glaucoma with variable results and complications. More recently, seton implantations of different types have become more popular to use in children, and newer techniques have become available including visualized cannulation and opening of Schlemm's canal, deep sclerectomy, trabectome, and milder more directed cyclodestructive procedures such as endolaser and transcleral diode laser cyclophotocoagulation. This paper reviews the different surgical techniques currently available, their indications, results, and most common complications to allow the surgeon treating these conditions to make a more informed choice in each particular case. Although the outcome of surgical treatment in pediatric glaucoma has improved significantly, its treatment remains challenging.

[Glaucoma surgery in childhood]

Technical characteristics and a long-term therapeutic strategy due to a long life expectancy play a key role in pediatric glaucoma surgery. The well-established angle surgery (goniotomy and trabeculotomy) achieves successful results in primary childhood glaucoma. Trabeculectomy seems to have been displaced as a secondary approach by glaucoma drainage devices (GDD) in primary childhood glaucoma due to inferior results, especially for children under 3 years of age. Even for secondary childhood glaucoma the results of GDD are encouraging, especially for therapy refractory aphakic glaucoma. In the first 2 years after GDD surgery success rates are about 80% for pediatric glaucoma and the results appear to be independent of the type of glaucoma and implant used. The complications of GDD are balanced to the faster intraocular pressure (IOP) control during the phase of visual acuity development. Cyclodestructive procedures may be applied as a secondary adjuvant approach but they increase the risk of conjunctival scarring and hypotony for subsequent procedures.

Dimensions of the human sclera: Thickness measurement and regional changes with axial length

Scleral thickness, especially near the region of the optic nerve head (ONH), is a potential factor of interest in the development of glaucomatous optic neuropathy. Our goal was to characterize the scleral thickness distribution and other geometric features of human eyes. Eleven enucleated human globes (7 normal and 4 ostensibly glaucomatous) were imaged using high-field microMRI, providing 80 microm isotropic resolution over the whole eye. The MRI scans were segmented to produce 3-D corneoscleral shells. Each shell was divided into 15 slices along the anterior-posterior axis of the eye, and each slice was further subdivided into the anatomical quadrants. Average thickness was measured in each region, producing 60 thickness measurements per eye. Hierarchical clustering was used to identify trends in the thickness distribution, and scleral geometric features were correlated with globe axial length. Thickness over the whole sclera was 670 +/- 80 microm (mean +/- SD; range: 564 microm-832 microm) over the 11 eyes. Maximum thickness occurred at the posterior pole of the eye, with mean thickness of 996 +/- 181 microm. Thickness decreased to a minimum at the equator, where a mean thickness of 491 +/- 91 microm was measured. Eyes with a reported history of glaucoma were found to have longer axial length, smaller ONH canal dimensions and thinner posterior sclera. Several geometrical parameters of the eye, including posterior scleral thickness, axial length, and ONH canal diameter, appear linked. Significant intra-individual and inter-individual variation in scleral thickness was evident. This may be indicative of inter-individual differences in ocular biomechanics.

Long-term results of surgery in childhood glaucoma

PURPOSE

The aim of this study is to assess the functional results and morphological parameters in children surgically treated for glaucoma.

METHODS

Data from 43 patients and 68 eyes who were operated in our department between 1990 and 2002 were collected. This retrospective trial included primary congenital glaucoma (n=36), and secondary glaucoma (n=7) in Rieger-Axenfeld syndrome and Sturge Weber syndrome. Intraocular pressure (IOP), axial length of the eyeball, visual acuity, refractive errors and orthoptic status were analysed.

RESULTS

The age of patients at the first surgery was 6.0 +/- 5.3 months (range 0.7 to 28.0 months). The mean period of follow-up was 57.3 +/- 36.8 months (6.0-161.0). The mean number of surgical procedures performed on one eye was 2.5 +/- 2.4 procedures (1-11). The mean IOP before the first surgery was 31.0 +/- 7.9 mmHg (17.5-52.0), and was 15.0 +/- 3.9 mmHg (7.0-28.0) at the last visit. 49 eyes (72.1%) did not need any further medical treatment after the last surgical procedure. The IOP was 18 mmHg or lower without medication in 29 eyes (42.6%) after just one surgical procedure (21 trabeculotomy, 8 combined trabeculotomy/trabeculectomy with or without mitomycin-C). At the first examination, the mean axial length of the eyeball was 22.6 +/- 1.8 mm (the mean normal value at this age is 20.3 +/- 0.7 mm), and was 24.4 +/- 2.0 mm at the last visit (the mean normal value at this age is 22.2 +/- 0.6 mm). The best corrected visual acuity at the last visit was 0.25 +/- 4.6 lines; the normal range of visual acuity at this age is from 0.4 +/- 4.0 lines to 0.8 +/- 3.0 lines. Visual acuity was 0.32 or more in 53.0% of the eyes. Visual acuity was lower than 0.1 in only 15.2% of the eyes. Myopia was present in 57.4% of the eyes with a mean spherical equivalent of -6.1 +/-3.9 dioptres. 15 patients (34.9%) developed strabismus. 22 patients (51.2%) were treated with part-time occlusion. Binocular function as assessed with the Lang-1 test was positive in 17 of 30 patients (56.7%).

CONCLUSIONS

Although a good long-term IOP-control can often be achieved in childhood glaucoma, the visual acuity remains below the normal range in most cases despite close orthoptic follow-up.

Ultrasound biomicroscopic characteristics of the anterior segment in primary congenital glaucoma

PURPOSE

To evaluate qualitatively and quantitatively ultrasound biomicroscopic (UBM) features of the anterior segment in eyes with primary congenital glaucoma.

METHODS

UBM of 45 eyes of patients with primary congenital glaucoma (39 previously operated and 6 unoperated eyes) and 28 control eyes were included in this study. UBM parameters were correlated with ocular biometry. Iris thickness, ciliary body thickness, ciliary body-lens distance, posterior chamber depth, and anterior chamber angle were measured and compared with control eyes. Other features of the anterior segment were qualitatively evaluated.

RESULTS

A thin, stretched-out ciliary body and abnormal tissue at the iridocorneal angle were features seen in 90% of UBM scans. Iris thickness and stretched zonules correlated with the axial length (r = -0.6 and 0.58, respectively; p = 0.04) but not with the mean corneal diameter. Abnormal insertion of the ciliary body to the posterior surface of the iris was noted in eight eyes (17%).

CONCLUSIONS

The present study documents characteristic anterior segment dysplasia and ciliary body anomalies in patients with primary congenital glaucoma.

Reliability and validity of the partial coherence interferometry for measurement of ocular axial length in children

PURPOSE

To assess the validity and repeatability of partial coherence interferometry (IOLMaster) and A-scan ultrasound measurement of axial length (AL) in children.

METHODS

A prospective comparison of AL measurement made by the IOLMaster optical instrument (Carl Zeiss) and ultrasound A-scan (Alcon) was performed. A total of 20 children (11 male, nine female) were recruited into the study; the mean age of the sample was 11.4 years (range 6.2-15.8). Inclusion criteria comprised individuals <16 years, with no ocular pathology and no previous eye operations or allergy to topical anaesthetics. All measurements were performed by a single examiner.

RESULTS

Data on validity show that, on average, a small measurement difference existed between these groups with the IOLMaster being 0.017 mm greater than A-scan ultrasonography. The 95% confidence interval for this difference encompasses zero, demonstrating that no significant systematic bias exists between the two-measurement techniques. Overall, IOLMaster reliability exceeded that of A-scan. This is evidenced primarily by the spread of the paired test-retest difference for A-scan compared to IOLMaster. The mean test-retest difference for A-scan was considerably larger than IOLMaster at 0.042 and 0.004 mm, respectively.

CONCLUSION

The results show that IOLMaster was more accurate and reproducible than the contact ultrasonographic technique when used in children. Such results indicate that IOLMaster may be a useful tool in studies of eye growth and refractive development in children.

Is the tono-pen accurate for measuring intraocular pressure in young children with congenital glaucoma?

PURPOSE

We sought to compare intraocular pressure (IOP) measurements by Perkins tonometer and Tono-Pen in young children with primary congenital glaucoma (PCG).

METHODS

This was a retrospective comparative case series. We reviewed the clinical records of all children with primary congenital glaucoma who underwent examinations under general anesthesia at Soroka University Medical Center between January 1999 and July 2002. Our main outcome measures were IOP with Perkins hand-held tonometer and Tono-Pen tonometer.

RESULTS

A total of 28 eyes of 16 children were examined under general anesthesia. The mean IOP was 18 +/- 6 mm Hg with the Perkins tonometer and 22 +/- 8 mm Hg with the Tono-Pen. In 18 eyes, IOP was less than 21 mm Hg with the Perkins tonometer; these eyes had already undergone surgical procedures. The other 10 eyes with IOP greater than 21 mm Hg with the Perkins tonometer underwent surgery at the end of the examination under anesthesia. In eyes with IOP greater than 16 mm Hg (Group A, n = 18), a significant difference (P < 0.001) was found between the Perkins and Tono-Pen measurements, even although the values were strongly correlated (r = 0.60). In contrast, in eyes with IOP less than 16 mm Hg (Group B, n = 10) no statistically significant difference (P = 0.28) and good correlation (r = 0.78) were obtained. A difference of 5.8 +/- 3.8 mm Hg and 0.6 +/- 1.7 mm Hg between Perkins and Tono-Pen readings, respectively, was found in Groups A and B.

CONCLUSIONS

Tono-Pen readings disagree with Perkins tonometer measurements for measuring IOP in children with PCG who present with IOP greater than 16 mm Hg and tends to overestimate IOP. A further study with a similar population is necessary to confirm these results.