Research progress on the pathogenesis of primary angle-closure glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

Primary angle-closure glaucoma(PACG)is a common cause of blindness, and angle closure is a fundamental pathologic process in PACG. With the development of ophthalmic equipment, the pathogenesis of PACG has been better understood. In addition to the traditional mechanisms of pupillary block and plateau iris, it has been found that its pathogenesis is not only related to abnormal ocular anatomy, but also more closely related to ocular dynamics, genetic factors, and psychophysiologic stressors. This article summarizes the pathogenesis and risk factors of PACG in conjunction with literature reports, with a view to providing guidance for clinical work and useful theoretical support for early diagnosis and treatment options for glaucoma.

Evaluation of changes in anterior segment morphology using Sirius Scheimpflug-Placido disk topographer following laser peripheral iridotomy in primary angle-closure disease

Purpose: To assess the morphological changes in the anterior segment following laser peripheral iridotomy (LPI) in primary angle?closure disease (PACD) using Sirius Scheimpflug?Placido disk corneal topographer. Methods: This was a prospective observational study. A total of 52 eyes of 27 patients with PACD who underwent LPI were analyzed for iridocorneal angle (ICA), anterior chamber depth (ACD), anterior chamber volume (ACV), horizontal visible iris diameter (HVID), corneal volume (CV), central corneal thickness (CCT), and horizontal anterior chamber diameter (HACD) 1 week following LPI, using Sirius Scheimpflug?Placido disk corneal topographer. Data analysis was done using Statistical Package for the Social Sciences (SPSS) software version 19.0, and paired t?test was used to assess the statistical significance. Results: Laser peripheral iridotomy was performed in 43 eyes with primary angle?closure suspect (PACS), six eyes with primary angle closure (PAC), and three eyes with primary angle?closure glaucoma (PACG). The analysis of the data showed statistically significant changes in anterior segment parameters of ICA, ACD, and ACV. Post?laser increase in ICA from 34.13° ± 2.64° to 34.75° ± 2.84° (P < 0.041), mean ACD increase from 2.21 ± 0.25 to 2.35 ± 0.27 mm (P = 0.01), and mean ACV increase from 98.19 ± 12.13 to 104.15 ± 11.16 mm3 (P = 0.001) were noted. Conclusion: Significantly quantifiable short?term changes in the anterior chamber parameters of ICA, ACD, and AC volume were seen after LPI in patients with PACD on Sirius Scheimpflug?Placido disc corneal topographer.

A comparison of lens parameters in patients with various subtypes of primary angle-closure disease and the normal population: A prospective study

Purpose: To assess the role of lens parameters in the detection and progression of primary angle-closure disease (PACD) by combining A-scan and A-scan optical coherence tomography (AS-OCT) parameters. Methods: A cross-sectional study was conducted in a tertiary health-care center in eastern India. A total of 91 study subjects including cases and controls were included in the study. The parameters studied were lens thickness (LT), lens axial factor (LAF), relative lens position (RLP), and lens vault (LV). Anterior chamber depth (ACD) and axial length (AL) were also analyzed using A-scan. Results: The LT was significantly more in all subtypes of PACD (from 4.24 ± 0.84 to 5.02 ± 0.18 mm) than in controls (4.04 ± 0.46 mm; P < 0.01). Similarly, LAF was significantly less among all subtypes of PACD compared to controls (P < 0.001). The RLP, calculated using the formula (ACD + 0.5 LT)/AL × 10, showed no significant difference (P > 0.05) between various study groups. The LV in acute angle-closure glaucoma (AcCG) patients was significantly higher compared to the control population (P < 0.01). Ocular parameters like ACD decreased, whereas LT and LAF increased from normal through primary angle closure (PAC) to primary angle-closure glaucoma (PACG). Logistic regression analysis found a significant association between a decrease in ACD and an increased risk of PACG (P-value was 0.0001) and an increase in LT and LAF with increased risk of PACG (P = 0.040 and P = 0.006, respectively). Conclusion: Inclusion of lens parameter assessment in the workup of a patient with PACD helps in detection and close monitoring of the progression from suspected to disease state.

Association of primary angle-closure disease in patients with retinal vein occlusion in North Indian population

Purpose: To determine the association of primary angle-closure disease (PACD) in patients with retinal vein occlusion (RVO) at a tertiary eye care center in North India. Methods: It is a cross-sectional, observational study. Sixty consecutive patients with retinal vein occlusion within a period of one year from a single tertiary eye care center were enrolled. Detailed history, slit-lamp examination of the anterior segment, intraocular pressure measurement by applanation tonometry, gonioscopy and fundus examination were done. Anterior chamber depth and axial length were also measured. Results: Among the 60 patients, 29 were males (48.3%) and 31 females (51.6%). Twenty-seven (45%) of them had central retinal vein occlusion (CRVO) and 33 (55%) had branch retinal vein occlusion (BRVO). Forty percent of patients with RVO had PACD. Relative risk of PACD was 1.71 times in patients with CRVO as compared to BRVO. Risk of glaucoma was 49% more in CRVO than BRVO. Probability of PACD was more in patients of RVO who had diabetes and CAD as comorbidity. Conclusion: The association between PACD and RVO is less known. PACD can be one of the risk factors for the development of RVO. A comprehensive examination and detailed angle evaluation of both of the eyes should be done in all cases of RVO, in addition to investigating for systemic risk factors. However, larger population-based studies would be required to prove it as an independent risk factor.

Prevalence of primary angle-closure disease in retinitis pigmentosa

To determine the prevalence of primary angle?closure disease (PACD) in patients with retinitis pigmentosa (RP). Methods: This was a retrospective review of the electronic medical records of all RP patients over the age of 10 years attending the Genetics Eye Clinic of a tertiary?care hospital during a 7?year period. Information regarding age, gender, vision, refraction, lens, intraocular pressure (IOP), type of RP, and inheritance pattern using pedigree charts for all patients were obtained. Patients with a shallow anterior chamber, high IOP, or glaucomatous optic discs were referred to the glaucoma department where they underwent additional IOP measurements, a gonioscopy, and disc evaluation by a glaucoma specialist. The prevalence of PACD was determined. Results: A total of 618 RP patients were examined during the study period, of which 95.1% had typical RP. The prevalence of primary angle?closure suspects was 2.9%, primary angle closure was 0.65%, and primary angle?closure glaucoma (PACG) was 2.27%. In contrast, the prevalence of primary open?angle glaucoma was 1.29%. The prevalence of PACG in those older than 40 years was 3.8% (95% confidence interval: 1.6–6.0). Conclusion: The prevalence of PACG in RP patients over 40 years was higher than that found in the general population of a similar age (3.8% vs. 0.8%). In our cohort of RP patients, 5.9% had PACD. Hence, gonioscopy is warranted in all RP patients to identify this condition and treat it appropriately.

Choroidal thickness in primary angle-closure disease / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To measure the macular and peripapillary choroidal thickness(CT)in primary angle-closure disease(PACD)with enhanced depth imaging optical coherence tomography(EDI-OCT). To explore the characteristics of CT in each subtypes of PACD and to evaluate its role in the pathogenesis of PACD.<p>METHODS: This was a prospective clinical study. A total of 155 PACD eyes(82 patients)were enrolled in the study, including 24 PACS eyes(24 patients), 35 APAC eyes(28 patients), 38 CPAC eyes(30 patients), 58 eyes PACG(38 patients). 87 normal eyes(87 patients)were set up as control. The EDI-OCT was used to measure the macular and peripapillary choroidal thickness in all study patients. <p>RESULTS: PACD eyes exhibited thicker choroid than the control eyes at all macular locations(<i>P</i><0.05). Choroidal thickness of PACG was thinner than other PACD eyes in area except for 3mm nasal from the fovea(<i>P</i><0.05). Subfoveal choroidal thickness(SFCT)of APAC was thickest(357.17±61.49μm), followed by PACS group(318.04±56.52μm). PACG group presented the thinnest SFCT(263.55±67.87μm). The average macular CT at 1mm centered at the fovea was thinner than SFCT(<i>P</i><0.05)in all subgroups except for CPAC. The average macular CT at 3mm as well as 1mm centered at the fovea was thinner than SFCT in all subgroups(<i>P</i><0.05). There was no statistical differences in CT at peripapillary locations between PACD and controls groups(<i>P</i>>0.05).<p>CONCLUSION: In PACD and controls groups, the CT of subfoveal location was the thickest with decreasing thickness when moving eccentrically from the fovea. The thicker CT might be another anatomic characteristic of PACD. Increased CT in macular location might be a contributing factor of acute attacks. There was no characteristic distinction in the peripapillary CT of PACD when compared with normal controls.

Evaluation of anterior segment parameters with two anterior segment optical coherence tomography systems: Visante and Casia, in primary angle closure disease

Purpose: To determine the comparability of anterior chamber biometric measurements in primary angle closure disease (PACD) patients using two commercially available anterior segment optical coherence tomography machines (ASOCT): Visante and Casia. Methods: This was a cross-sectional observational study, which included clinically, diagnosed cases of PACD. Anterior segment biometric measurements were done using Casia and Visante ASOCT. Parameters studied were central corneal thickness (CCT), anterior chamber depth (ACD), nasal (N) and temporal (T) angle opening distance at 500 ?m (AOD500) and 750 ?m (AOD750), and N and T trabecular iris space area at 500 ?m (TISA500) and 750 ?m (TISA750). Results: Total 36 PACD patients (72 eyes) with average age of 59.48 ± 7.95 years were recruited, out of which 25 were females (69.44%) and 11 males (30.56%). The mean measurements of CCT, ACD, AOD500, and TISA on Casia and Visante machines were 522.5 ± 34.75 ?m and 539.55 ± 29.56 ?m (P = 0.00); ACD- 2.144 ± 0.38 mm and 2.133 ± 0.39 mm (P = 0.487); AOD500-0.27 ± 0.16 ?m and 0.21 ± 0.10 ?m (P = 0.04); and TISA500-0.100 ± 0.07 ?m and 0.063 ± 0.03 ?m (P = 0.00), respectively. A statistically significant difference was noted in CCT, N and T AOD, and TISA. A good corelation for ACD and CCT (ACD = 0.9816 and CCT = 0.772) only were noted between the two machines. The Bland-Altman plot analysis of different parameters between two machines has revealed good agreement of measurement of ACD and CCT but poor agreement for rest of the parameters. Conclusion: It is advisable not use the two machines interchangeably because of the wide limits of agreement and poor correlation of angle measurement values of Casia and Visante ASOCT.

Angle closure glaucoma in rural and urban populations in eastern India—The Hooghly River Glaucoma Study

Purpose: To estimate the prevalence, features, and associations of primary angle closure disease (PACD) in rural and urban populations from West Bengal in eastern India. Methods: This was a population-based cross-sectional study with two arms, rural and urban. The rural study area consisted of 28 contiguous villages from 13 gram panchayats in Balagarh Police Station, with rural base hospital at Dhobapara, Balagarh Police Station, in the village Kuliapara of Hooghly district. A tertiary eye hospital in central Kolkata was the urban study center. Individuals residing in the study area aged 40 years and above were included in this study using multistage random cluster sampling. All subjects underwent a detailed ophthalmic examination at our base hospitals including applanation tonometry, ultrasound pachymetry, gonioscopy, and frequency doubling technology perimetry. Data collected were analyzed using SPSS 13. Multiple logistic regressions were used to analyze risk factors for PACD. Results: A total of 7,408 and 7,248 subjects aged 40 years or older were enumerated from Hooghly district and Kolkata city, respectively. PACD was detected in 1.9% subjects in rural arm and 1.54% subjects in the urban arm (P < 0.001). In rural arm, 0.3% had PACS, 0.56% had PAC, and 1.03% had PACG. In urban arm, 0.22% had PACS, 0.35% had PAC, and 0.97% had PACG. Conclusion: The study concludes that higher age, higher CCT, and shorter axial length/presence of hyperopia are important independent predictors of ACD. ACD is more common in eastern India than previous estimates.

Changes of postoperative macular structure in primary angle closure disease complicated with cataract / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM: To explore the change of postoperative macular structure in primary angle closure disease (PACD) complicated with cataract. ·METHODS: The clinical data of 200 cases of PACD patients complicated with cataract treated in our hospital were analyzed retrospectively. The patients were divided into the Group A (n = 60, 60 eyes, treated with trabeculectomy),the Group B(n=72,72 eyes,given the phacoemulsification combined with intraocular lens implantation) and the Group C (n=68, 68 eyes, given the trabeculectomy and phacoemulsification combined with intraocular lens implantation). The vision changes before and after treatment and the changes of intraocular pressure and macular thickness (foveal area, near central area, foveal surrounding area) before operation and at 1wk, 1 and 3mo after operation were compared and observed, and the incidence of complications was compared between the two groups. ·RESULTS: There were significant differences in the improvement rate and reduction rate of visual acuity among three groups at 3mo after operation (P<0.01), and the vision improvement rate in Group C was highest,while that in the Group A was the lowest. The intraocular pressure (IOP) of the three groups at 1wk,1 and 3mo after operation was significantly lower than that before operation (P<0.05), and the IOP in the Group B was significant higher than that in the Group A and the Group C at 1wk, 1mo after operation (P<0. 05), and there were significant differences in the thickness of foveal area and near central area among three groups before and after operation (P<0.05). And the macular thickness ( foveal area, near central area, foveal surrounding area) in the Group A and C at 1wk, 1 and 3mo after operation was significantly thicker than that before operation(P<0.05),and the macular thickness of foveal area in the Group B was significantly thicker at 1wk and 1mo after operation than that before operation (P<0.05). And the comparison between groups showed that the macular thickness (foveal area, near central area) in the Group C at 1wk,1 and 3mo after operation was significantly less compared with that in the Group A and the Group B (P< 0. 05). There were significant differences in the incidence rate of complications among three groups (P<0.01), and the incidence rate in the Group A was significantly higher than that in the Group B and the Group C (P<0.05). · CONCLUSION: Phacoemulsification combined with intraocular lens implantation can relieve angle closure caused by pupillary block and lens factors, and can significantly improve the vision and reduce intraocular pressure of PACD patients with cataract,and it has small effects on postoperative macular edema with few complications.

An Indian perspective on primary angle closure and glaucoma.

Aim: To provide a synopsis of primary angle closure disease in India, and Indian studies on the same. Results: Primary angle closure glaucoma forms almost half of all adult primary glaucomas seen in a hospital setting in India. Anatomically, corneal diameters and anterior chamber depths were least in acute and chronic PACG eyes as compared to subacute eyes and controls. Besides relative pupillary block, a Valsalva maneuver during activities of daily living may be responsible for intermittent angle closure and raised IOP in predisposed eyes. Iridotomy alone, controlled the intraocular pressure in 66.7% of subacute eyes and 12.9% of the acute. Medical therapy was additionally required for 35.5% of the acute eyes, 12.1% of the subacute and 30.0% of the chronic cases. There was a greater mean and peak IOP reduction, achieved with 0.005% latanoprost once daily, 8.2 ± 2.0 mm Hg, compared with 0.5% timolol twice daily, 6.1 ± 1.7 mm Hg2. A progression of PACS to PAC was seen in 22%, PAC to PAC OHT in 38.7% and PAC OHT to PACG in 30.7% over 5 years. Conclusions: Primary angle closure disease is common in India, and can be managed well with iridotomy, followed by an appropriate control of IOP.