Primary Congenital Glaucoma Patients Research Articles

Mutation Screening of the CYP1B1 Gene Reveals Novel and Recurrent Pathogenic Variants in Pakistani Primary Congenital Glaucoma Patients

Mutation Screening of the CYP1B1 Gene Reveals Novel and Recurrent Pathogenic Variants in Pakistani Primary Congenital Glaucoma Patients

Macular and peripapillary vascular parameters in the fellow eyes of unilateral primary congenital glaucoma: a comparative study

PurposeTo study the fellow eyes of patients with unilateral primary congenital glaucoma (PCG) using optical coherence tomography angiography (OCTA) and compare them to normal age- and refractive error–matched healthy controls. MethodsUsing OCTA, the foveal avascular zone (FAZ) area, cup:disk ratio, vessel density (VD) of the optic nerve head (ONH) and peripapillary area and the macular VD in superficial (SCP) and deep vascular complexes in both 3 mm and 6 mm scans of both groups were compared. Clinical data included best-corrected visual acuity (BCVA), cycloplegic refraction, intraocular pressure (IOP), anterior and posterior segments examination findings, including ONH cup:disk ratio. ResultsA total of 48 eyes of 48 children (24 eyes in each group) were included. There was no difference in the mean RNFL thickness, cup:disk ratio, baseline visual acuity, or spherical equivalent between groups (P > 0.05). In the 3 mm macular scan, the VD of the SCP at the fovea was significantly higher in the PCG group compared to controls (P = 0.04). In the ONH scans, there was a significantly reduced inside the disk VD in the PCG group compared to controls (P = 0.03). There was no significant difference in other macular and ONH vascular parameters between groups (P > 0.05). ConclusionsIn our study cohort, there was no difference in most of the macular and ONH vascular parameters between groups. However, the fellow eyes of PCG patients exhibited higher VD of the SCP at the fovea and reduced inside the disk VD compared with control eyes.

Detección y caracterización de defectos del campo visual mediante perimetría Octopus en glaucoma congénito primario

PurposeTo detect and characterise visual field (VF) defects using static Octopus perimetry in patients with primary congenital glaucoma (PCG) and to determine VF quality and time duration. Material and methodsEighty-eight eyes of 70 patients diagnosed with PCG were included. Assessments were performed using an Octopus 900 and each eye was assessed with the tendency-oriented perimetry (G-TOP) algorithm. Quantitative VF data were collected: quality data (false positive and negative response, and time duration) and results of mean deviation (MD) and square root of loss variance (sLV). Qualitative data were collected: the presence of diffuse and localized defects, the affected hemifield and grade of defects using the Aulhorn and Karmeyer classification. Correlations between perimetric results and clinical variables were analysed. ResultsMedian age was 11 (8-17) years. 65.9% (58/88) of PCG eyes showed VF defects. Diffuse defects were observed in 10/58 eyes (16.94%) (mean MD=23.92 [SD: 2.52]) dB) and localized defects in 48/58 eyes (82.75%). The most frequent defect was spot-like/stroke-like/incipient paracentral scotoma (n=15), nasal step (n=8), adding arcuate defect (n=2), half ring-shaped (n=13) and concentric defect with a central island (n=9). And the most frequent affected visual hemifield was inferior hemifield. Mean test duration was 2min 12s (SD: 21.6s). MD and sLV values were correlated with best corrected visual acuity (BCVA), cup to disc ratio and number of antiglaucoma surgeries (all P<.001). ConclusionA high number of diffuse and localized defects were identified using Octopus perimetry in PCG patients. The most frequent defect was paracentral scotoma and inferior hemifield was the most affected.

Detection and characterisation of visual field defects using Octopus perimetry in congenital glaucoma

PurposeTo detect and characterise visual field (VF) defects using static Octopus perimetry in patients with primary congenital glaucoma (PCG) and to determine VF quality and time duration. Material and methodsEighty-eight eyes of 70 patients diagnosed with PCG were included. Assessments were performed using an Octopus 900 and each eye was assessed with the tendency-oriented perimetry (G-TOP) algorithm. Quantitative VF data were collected: quality data (false positive and negative response, and time duration) and results of mean deviation (MD) and square root of loss variance (sLV). Qualitative data were collected: the presence of diffuse and localized defects, the affected hemifield and grade of defects using the Aulhorn and Karmeyer classification. Correlations between perimetric results and clinical variables were analysed. ResultsMedian age was 11 (8–17) years. 65.9% (58/88) of PCG eyes showed VF defects. Diffuse defects were observed in 10/58 eyes (16.94%) (mean MD = 23.92 [SD: 2.52]) dB) and localized defects in 48/58 eyes (82.75%). The most frequent defect was spot-like/stroke-like/incipient paracentral scotoma (n = 15), nasal step (n = 8), adding arcuate defect (n = 2), half ring-shaped (n = 13) and concentric defect with a central island (n = 9). And the most frequent affected visual hemifield was inferior hemifield. Mean test duration was 2 min 12 s (SD: 21.6 s). MD and sLV values were correlated with best corrected visual acuity (BCVA), cup to disc ratio and number of antiglaucoma surgeries (all P < .001). ConclusionA high number of diffuse and localized defects were identified using Octopus perimetry in PCG patients. The most frequent defect was paracentral scotoma and inferior hemifield was the most affected.

The correlation of anterior segment structures in primary congenital glaucoma by ultrasound biomicroscopy with disease severity and surgical outcomes

PurposeTo evaluate the anterior segment structures using ultrasound biomicroscopy (UBM) in primary congenital glaucoma (PCG) and explore their correlation with disease severity and surgical outcomes.MethodsClinical information of PCG patients who underwent UBM prior to their first glaucoma surgeries from September 2014 to March 2021 were reviewed. The study included 214 UBM images of 154 PCG eyes and 60 fellow unaffected eyes. Anterior segment characteristics were analyzed. UBM parameters, including the iris thickness (IT) at variant distances from the pupil edge and iris root, anterior chamber depth (ACD), and pupil diameter (PD), were compared between two groups and their relationship with clinical factors and surgical outcomes were analyzed in PCG eyes.ResultsPCG eyes had unclear scleral spur, thin iris, wide anterior chamber angle, deep anterior chamber, rarefied ciliary body, elongated ciliary processes, and abnormal anterior iris insertion. ITs were thinner, ACD was deeper, and PD was larger in PCG eyes than fellow unaffected eyes (all P < 0.001). In PCG eyes, thinner ITs correlated with bilateral involvement and earlier age at presentation, and larger PD correlated with earlier age at presentation (P = 0.030) and higher intraocular pressure (P < 0.001). Thinner IT2 (P = 0.046) and larger PD (P = 0.049) were identified as risk factors for surgical failure.ConclusionUBM is a powerful technique to exam anterior segment structures in PCG. The anatomical features are associated with disease severity and surgical outcomes, providing essential clinical insights.

Thrombospondin Mutations and Primary Congenital Glaucoma Patients in a United States Population.

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Aqueous Humor Cytokine Profile in Primary Congenital Glaucoma.

Cytokine profile in patients with primary open-angle glaucoma (POAG) differs from that in healthy controls. Due to the different pathophysiological mechanisms involved in the genesis of primary congenital glaucoma (PCG) and POAG, it is possible that the cytokine profile could also differ. The main objective of this study was to compare the concentrations of cytokines in the aqueous humor of patients with PCG with those of POAG patients and a control group. A cross-sectional study was conducted. Aqueous humor samples were taken from PCG and POAG patients eligible for glaucoma or cataract surgery and from patients undergoing cataract surgery. Twenty-seven cytokines were analyzed using the Human Cytokine 27-Plex Immunoassay Kit (Bio-Rad Laboratories, Hercules, CA, USA). A total of 107 subjects were included: patients with PCG (n = 19), patients with POAG (n = 54), and a control group (CG) of patients undergoing cataract surgery (n = 34). Most cytokines measured in aqueous humor in PCG presented decreased values compared with POAG and controls. A statistically significant difference was observed in IL-1ra, IL-2, IL-5, IL-7, IL-8, IL-10, IL-12, IL-15, IL-17A, Eotaxin, FGF basic, G-CSF, GM-CSF, IFN-γ, MIP-1α, PDGF-bb, MIP-1β, RANTES, TNF-α, and VEGF. PCG patients have a cytokine profile in aqueous humor different from POAG patients and patients without glaucoma, characterized by lower concentrations of multiple cytokines.

High prevalence of glaucoma-associated CYP1B1 mutation (p.G61E) in primary congenital and open angle glaucoma patients in Pakistan

The Journal of the National Science Foundation of Sri Lanka publishes the results of research in all aspects of Science and Technology. The journal also has a website at http://www.nsf.gov.lk/. 2021 Impact Factor: 0.682The JNSF provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.

Ocular Aberrations in Eyes with Primary Congenital Glaucoma

Purpose To highlight the magnitude of ocular higher order aberrations (HOA) and lower order aberrations (LOA), including component contributions from corneal and internal planes in Primary Congenital Glaucoma (PCG) patients. Methods Consecutive treated PCG patients co-operative for ocular examination and aberrometry, were enrolled over two years for this cross-sectional, comparative, single-center, unmasked study. Best-corrected visual acuity, refraction, IOP, wavefront aberrometry and topography (iTrace) were performed and results were compared with unaffected fellow eyes of unilateral glaucoma patients as well as age and sex-matched controls with no ocular anomalies other than treatable refractive error. Results Both eyes of 32 consecutive PCG patients (17 unilateral, 15 bilateral) and 39 controls were enrolled. The median LogMAR corrected distance visual acuity of PCG eyes was 0.68 (IQR: 0.2–1.8). Total ocular (Root mean square (RMS) 1.7 µm vs 0.3 µm, p = 0.014), corneal (RMS 1.1 µm vs 0.3 µm, p = 0.004) and internal (RMS 1.1 µm vs 0.2 µm, p = 0.013) aberrations, as well as HOAs and LOAs at each plane, were significantly higher in PCG eyes than in controls. Component HOAs from corneal and internal planes were positively correlated with each other (p < 0.001; rs: 0.7). Total aberrations were greater in the affected eyes of PCG compared to the rest. The predominant subtype of HOAs in PCG was coma and trefoil. PCG with corneal opacity/Haab’s striae had significantly higher astigmatism than the affected eyes with clear corneae at the corneal plane (p = 0.02). The aberrations were not statistically associated with the corneal diameter or refractive error in PCG eyes. Conclusions Significantly greater aberrations (Total, HOAs and LOAs, at corneal as well as an internal plane) were seen among eyes affected with PCG. Though the exact impact of these aberrations on the final visual outcome is difficult to determine, these could play a pertinent role in compromising visual function, thus impacting the management of visual rehabilitation in these patients.

Consanguinity and severity of primary congenital glaucoma

To evaluate the severity of primary congenital glaucoma (PCG) among children born of consanguineous marriage. In this case-control study, the medical records of unrelated consanguineous patients and unrelated nonconsanguineous (control) PCG patients seen at a single tertiary eye care facility were retrospectively reviewed. Those with a minimum of 5 years' follow-up were included. Data collected included age at presentation, corneal diameter, axial length, corneal haze at presentation and its persistence after surgery, need for repeat surgery, and final visual acuity. A total of 130 PCG patients were included: 30 patients born of consanguineous marriage and 100 nonconsanguineous control patients. The median age of presentation for consanguineous cases was 3 months (range, 1-36) compared with 10 months (range, 2-24) for nonconsanguineous cases (P < 0.001). Mean corneal diameter for consanguineous cases was 13 ± 0.82 mm and for nonconsanguineous cases was 12.41mm ± 1.18 mm (P = 0.002). Consanguineous cases also had a significantly higher prevalence of corneal haze persisting after surgery (P < 0.001) and need for repeat IOP-lowering surgery (P = 0.039). The consanguineous group had 44 eyes (73%) with severe PCG compared with 69 (34.5%) in the nonconsanguineous group (P < 0.001). In this study cohort, children with PCG born of consanguineous parents were more severely affected at presentation compared with children born of nonconsanguineous parents; they also had poorer outcomes with IOP-lowering surgery independent of severity at presentation. It is however possible that a founder effect with consanguinity over multiple generations could account for our observations.

Exome-based mutation screening in South African children with primary congenital glaucoma.

To identify pathogenic variants in a cohort of 23 black South African children with sporadic primary congenital glaucoma (PCG) using an exome-based approach. Children with PCG were recruited from two Paediatric Ophthalmology Clinics in Johannesburg, South Africa. Whole exome sequencing was performed on genomic DNA. Of the 23 children, 19 were male and 19 had bilateral PCG. A variant prioritization strategy was employed whereby variants in known PCG genes (CYP1B1, LTBP2 and TEK) were evaluated first, followed by the identification of putative disease-causing variants in other genes related to eye diseases and phenotypes. Validated pathogenic variants in the CYP1B1 gene (c.1169 G>A; p.Arg390His) and TEK gene (c.922 G>A; p.Gly308Arg) were identified in one child each. No LTBP2 mutations were identified in this cohort. In silico predictions identified potentially damaging rare variants in genes previously associated with eye development phenotypes or glaucoma in a further 12 children. This study demonstrates the value of whole exome sequencing in identifying disease-causing variants in African children with PCG. It is the first report of a TEK disease-causing variant in an African PCG patient. Potential causative variants detected in PCG candidate genes warrant further investigation.

Outcomes of Surgical Interventions in Primary Congenital Glaucoma Patients.

The aim was to report long-term surgical success of primary congenital glaucoma (PCG) patients in Thailand. PCG patients who underwent one of the following primary operations: trabeculotomy, goniotomy, trabeculectomy, combined trabeculotrabeculectomy (CTT) and diode transscleral cyclophotocoagulation (TSCPC) between January 1992 and January 2018 were reviewed. Surgical success was defined as intraocular pressure (IOP) between 5 and 21 mm Hg with or without antiglaucoma medications. Failure was defined as IOP ≤5 or ≥21 mm Hg for 2 consecutive visits, or when an additional glaucoma surgery was required to control IOP. Survival curves were analyzed using multilevel mixed-effect Weibull model. A total of 81 eyes from 55 PCG patients were included. Surgical procedures involved 20 goniotomies, 15 trabeculotomies, 16 trabeculectomies, 15 CTT, and 15 TSCPC. Median follow-up time was 24 months (interquartile range: 9 to 60 mo). Overall success rates were 68.8% at 1 year, 63.8% at 3 years, and 53.7% at 5 years. All types of surgery except TSCPC had comparable cumulative 1 year success rates ranging from 78.5% to 83.3%. Cumulative success rates of trabeculotomy (80.05%) and CTT (79.4%) were maintained at 3 and 5 years and were the highest among all procedures at 5 years. TSCPC had a significantly lower success rate compared with other types of surgery (hazard ratio: 7.4 to 13.1, all P=0.01). All patients receiving primary TSCPC showed no success at 48 months. Primary trabeculotomy and primary CTT demonstrated the highest long-term success rates in PCG patients.

Trabeculotomy Versus Combined Trabeculotomy-Trabeculectomy for Management of Primary Congenital Glaucoma.

Trabeculotomy (T) alone is as safe and effective as combined trabeculotomy-trabeculectomy (TT) in patients with primary congenital glaucoma (PCG) and requires significantly fewer examinations under anesthesia in the postoperative period. The purpose of this study was to compare the outcomes of T and combined TT as the initial surgical procedure for patients with PCG. In this retrospective study, medical records of patients who had undergone T or TT as the initial procedure for PCG were reviewed. The primary outcome measure was a surgical success, defined as 5≤ intraocular pressure (IOP) ≤21 mm Hg, IOP reduction of at least 20% with no need for further glaucoma surgery. Secondary outcome measures were the number of glaucoma medications and complications. A total of 134 eyes from 134 patients with a mean follow-up of 8±6.6 years were included consisting of 106 and 28 eyes, which had undergone T and TT, respectively. Success rates were comparable with both surgical procedures at 1, 2, 3, 4, and 5 years with no statistically significant difference. IOP was significantly decreased from 27.5±4.2 mm Hg preoperatively to 15.62±3.4 mm Hg at the 5-year follow-up visit in the T group and from 25.3±6.5 to 17.1±3.2 mm Hg in the TT group (P=0.1) there was no significant difference between the 2 groups in the number of glaucoma medications (P=0.2). Patients in the T group required significantly fewer examinations under anesthesia than the TT group (7.3±4.4 vs. 10.1±3.9, P=0.04). Trabeculotomy alone seems as effective as combined trabeculotomy-trabeculectomy and may significantly reduce exposure to anesthesia in primary congenital glaucoma patients.

Peripapillary and macular vascular parameters by optical coherence tomography angiography in primary congenital glaucoma.

To evaluate the differences in peripapillary and macular vascular parameters by optical coherence tomography angiography (OCTA) between patients with primary congenital glaucoma (PCG) and healthy controls; and to determine their diagnostic accuracy. Observational, cross-sectional study including 39 eyes with PCG and 78 healthy eyes. Only one eye per patient was included. All included patients underwent a comprehensive ophthalmic examination and peripapillary and macular analysis were performed by AngioplexTM OCTA (Cirrus HD-OCT 5000) with a 4.5 × 4.5 mm optic nerve head scan and 6 × 6 mm macular scan. Global data and quadrant data from peripapillary vascular parameters and global data and circular sectors data from macular superficial plexus parameters were compared between groups. The glaucoma discrimination capability of these parameters was calculated as areas under the receiver operating characteristics curve (AUC ROC). Mean age was 14.1 ± 8.7 years for the PCG patients and 11.7 ± 6.2 years for controls (p = 0.093). All vascular peripapillary measurements (global and quadrants; all p < 0.001) and all macular measurements (p < 0.042) excepting perfusion density in the inner circle (p = 0.087), were reduced in the PCG group compared to controls. According to AUC ROC, peripapillary (all ≥ 0.706) and macular parameters (all ≥ 0.699) showed good diagnostic capacity. AUC ROC for the most discriminatory measurements corresponding to blood flux index (0.887) and whole macula vascular density (0.855) were similar (p = 0.085). Peripapillary and macular vascular parameters by OCTA are decreased in patients with PCG, showing a good capacity to discriminate between normal and glaucomatous eyes.

Long-Term Visual Outcomes of Primary Congenital Glaucoma in China

Introduction: The aim of this study was to investigate the long-term visual outcomes and factors associated with vision loss in Chinese patients with primary congenital glaucoma (PCG) after successful intraocular pressure (IOP) control (IOP ≤21 mm Hg). Methods: PCG patients with IOP control who were examined in the glaucoma clinic at Zhongshan Ophthalmic Center from 2019 to 2020 were enrolled. The final visual outcome was evaluated by the best corrected visual acuity (VA). Univariate and multivariate analyses were used to investigate the associations of visual impairment with potential risk factors. The causes for decreased VA (<20/50) were also analyzed. Results: Fifty-nine patients (95 eyes) were included in the cohort, with a mean age of 8.7 years. The mean logMAR VA was 0.62 ± 0.64. The VAs of eyes treated for PCG were good (≥20/50) in 56%, fair (20/60–20/200) in 30%, and poor (<20/200) in 14%. The most common cause of decreased VA was amblyopia (64.3%). Multivariate logistic regression analysis showed that undergoing multiple surgeries (OR: 4.86, 95% CI: 1.11–21.16, p = 0.035) was significantly associated with visual impairment. Conclusion: The results showed that good VA was attainable in approximately half of PCG eyes under IOP control. Prompt and effective treatment of PCG, management of amblyopia and ocular comorbidities may be potential steps toward achieving good visual outcomes in PCG patients.

Factors Affecting Final Surgical Outcome of Combined Trabeculotomy-Trabeculectomy in Primary Congenital Glaucoma.

PurposeTo evaluate different pre-operative variables on the success of combined trabeculotomy–trabeculectomy (CTT) surgery in patients with primary congenital glaucoma (PCG) to predict those at higher risk for surgical failure and for proper parent counseling.Patients and MethodsSixty-three eyes of patients with PCG were treated either with CTT without augmentation, or CTT augmented with mitomycin-C (0.2 mg/mL) in both subconjunctival space and under scleral flap for 3 minutes, or with CTT augmented with a collagen implant under both the scleral flap and the conjunctiva. Cases showed surgical failure was reported and evaluated in relation to different pre-operative variables.ResultsComplete success (IOP ≤21 mmHg) was achieved in 52 cases (82.5%). Cumulative success probability was calculated using Kaplan-Meier survival analysis, proving that higher pre-operative intraocular pressure (IOP) was associated with higher failure rates (28.6% for pre-operative IOP ≥30 mmHg versus 4.8% for IOP <30 mmHg), with P value = 0.007.ConclusionCTT is an effective surgical intervention in PCG patients without sight threatening complications. Univariate survival analysis showed higher rates of surgical failure in patients with higher pre-operative IOP, while other pre-operative variables were irrelevant.

Posterior corneal morphological changes in primary congenital glaucoma.

Purpose:To compare posterior corneal morphology between older treated and younger untreated children with primary congenital glaucoma (PCG) using anterior segment optical coherence tomography (ASOCT) and intraoperative OCT (iOCT), respectively.Methods: In this comparative study, ASOCT of older PCG children were compared with iOCT of younger untreated PCG patients. Differences between the two groups with respect to posterior corneal morphology were studied.Results: Observed morphological patterns within posterior cornea in older treated (age: 72–300 months) children (87 eyes) included Descemet’s membrane (DM) excrescences (70%), thickened DM (35%), intracameral twin protuberances (92%), and DM detachment (26%). Changes within pre-Descemet’s layer (PDL) (28%) included thickening, breaks, and detachments. Extent of Haab’s striae was associated with thickness of DM/PDL complex (P = 0.008) when analyzed in the treated group. In contrast, in the untreated group (n = 53 eyes, age 1–63 months), posterior corneal changes were limited to diffuse hyper-reflectivity of the DM/PDL complex, with absence of DM tears.Conclusion: Posterior cornea thickens and Haab’s striae become more circumscribed in eyes of older treated children compared to untreated PCG eyes, probably reflecting a healing response of posterior cornea over time.

Screening and Functional Analysis of TEK Mutations in Chinese Children With Primary Congenital Glaucoma.

Purposes: Recent studies have suggested that loss-of-function mutations of the tunica intima endothelial receptor tyrosine kinase (TEK) are responsible for approximately 5% of primary congenital glaucoma (PCG) cases in diverse populations. However, the causative role of TEK mutations has not been studied in Chinese PCG patients. Here, we report the mutation spectrum of TEK after screening a large cohort of PCG patients of Chinese Han origin and analyze the identified variants in functional assays. Methods: TEK-targeted next-generation sequencing (NGS) was performed in 200 PCG patients. Candidate variants were prioritized by mutation type and allele frequency in public datasets. Plasmids containing wild type and identified variants of TEK were constructed and used to assess protein expression, solubility, receptor auto-phosphorylation, and response to ligand stimulation in cell-based assays. Results: Ten missense and one nonsense heterozygous variants were detected by NGS in 11 families. The clinical features of TEK variants carriers were comparable to that of TEK-mutated patients identified in other populations and CYP1B1-mutated individuals from in-house database. Functional analysis confirmed four variants involving evolutionarily conserved residues to be loss-of-function, while one variant (p.R1003H) located in tyrosine kinase domain seemed to be an activating mutation. However, our results did not support the pathogenicity of the other five variants (p.H52R, p.M131I, p.M228V, p.H494Y, and p.L888P). Conclusion: We provide evidence for TEK variants to be causative in Chinese PCG patients for the first time. Attention needs to be paid to TEK mutations in future genetic testing.

Combined trabeculotomy-trabeculectomy for primary congenital glaucoma: long-term experience from a tertiary referral centre in a developing nation.

To evaluate the long-term visual and surgical outcomes, and associated risk factors for poor outcomes in patients with primary congenital glaucoma (PCG). Retrospective review of medical records of children who underwent combined trabeculotomy-trabeculectomy (CTT) without mitomycin-C as the first surgical procedure by a single surgeon between January 1990 and December 2010. Success was defined as intraocular pressure (IOP) <16 mmHg without (complete) or with (qualified) one glaucoma medication. We used the WHO criteria of vision loss to categorize the levels of vision impairment (VI). For purposes of statistical analysis, we randomly chose one eye of patients for bilateral PCG and affected eye in unilateral PCG. The cohort included 653 consecutive PCG patients (1128 eyes; mean age, 26 months), of whom 475 (73%) underwent simultaneous bilateral CTT. Kaplan-Meier survival analysis revealed 1-, 5-, 10-, 15-, and 19-year complete success rates of 92.6% (n = 372), 75.5% (n = 173), 55.9% (n = 72), 44.7% (n = 19), and 21.6% (n = 3), respectively. Multivariate analysis revealed independent associations between failure, preoperative corneal clarity, and prior glaucoma surgery. Mean follow-up was 41 ± 51 months (range, 6 months to 19 years; median, 1 year). Of the visual acuity (VA) data in the affected eyes obtained at last follow-up (n = 333, 51%), seventy-four patients (22%) had VA of ≥6/12. Of the remaining 259 patients, 18 (7%) had mild VI, 87 (34%) had moderate VI, 58 (22%) had severe VI, and 96 (37%) were blind. No serious complications were noted. Primary CTT may be safely employed to control IOP and may provide long-term benefits in PCG patients.

Effects of Corneal Biomechanical Properties on Rebound Tonometry (Icare200) and Applanation Tonometry (Perkins) Readings in Patients With Primary Congenital Glaucoma.

The aim was to assess the influence of corneal biomechanics on intraocular pressure (IOP) measurements made with the Icare200 (IC200) rebound tonometer and the Perkins handheld applanation tonometer in patients with primary congenital glaucoma (PCG). A total of 40 PCG patients and 40 healthy controls, age, and sex-matched, were recruited. IOP was measured with the Ocular Response Analyzer (IOPc, IOPg), IC200 and Perkins. The variables age, IOP, corneal hysteresis (CH), corneal resistance factor (CRF), central corneal thickness (CCT), best-corrected visual acuity, spherical equivalent, medications, and glaucoma surgeries were recorded for each subject. Univariate and multivariate analysis were used to detect effects of variables on IOP measurements. Mean CCT was 545.65±71.88 μm in PCG versus 558.78±27.58 μm in controls (P=0.284). CH and CRF were significantly lower in PCG group than in control group: mean CH 8.11±1.69 versus 11.15±1.63 mm Hg (P<0.001), and mean CRF 9.27±2.35 versus 10.71±1.75 mm Hg (P=0.002). Mean differences between IOP IC200-Perkins were 0.79±0.53 mm Hg in PCG versus 0.80±0.23 mm Hg in controls (P<0.001) and mean differences IC200-IOPc were -0.89±5.15 mm Hg in PCG (P<0.001) versus 1.60±3.03 mm Hg in controls (all P<0.009). Through multivariate analysis, CRF showed positive association and CH negative association with IOP measured with Perkins or IC200 in both subject groups. No association was detected for CCT, age, or sex. CH and CRF were identified as the main factors interfering with IOP measurements made with both tonometers in patients with PCG and healthy controls.