Central Anterior Chamber Depth Research Articles

Anterior segment morphology after laser iridotomy in primary angle closure suspects

PurposeTo evaluate and compare the changes in anterior segment parameters in primary angle closure suspects before and after laser peripheral iridotomy and intrasession repeatability of measurements before laser iridotomy as assessed by Scheimpflug‐Placido disc topographer.MethodsBefore laser iridotomy, 56 eyes of 56 primary angle closure suspect patients underwent anterior segment analysis with the Sirius Scheimpflug‐Placido disc topographer system using glaucoma analysis mode, which was repeated a week after iridotomy. Anterior segment parameters such as central anterior chamber depth, central corneal thickness, anterior chamber volume and iridocorneal angle were analysed before and after laser iridotomy and compared with paired t‐test. Three consecutive scans were obtained to assess the intrasession repeatability of measurements before iridotomy by a single examiner and intraclass correlation co‐efficient was calculated. Multivariate regression analysis was performed to evaluate the predictors associated with iridocorneal angle narrowing.ResultsIntraclass correlation co‐efficient values ranged from 0.982 for anterior chamber volume to 0.998 for the iridocorneal angle. After laser iridotomy, mean central anterior chamber depth increased from 2.14 ± 0.29-mm to 2.21 ± 0.28-mm (p = 0.04), mean anterior chamber volume increased from 96.2 ± 16.98-mm3 to 98.14 ± 15.87-mm3 (p < 0.0001) and mean iridocorneal angle widened from 33.38 ± 3.96° to 34.82 ± 4.27° (p = 0.01), compared with pre‐iridotomy status. There was no change in central corneal thickness, intraocular pressure or pupil diameter. Multivariate regression analysis model showed that at one week after iridotomy, iridocorneal angle opening was positively correlated with age (β = 0.773, p = 0.005) and anterior chamber volume (β = 1.308, p < 0.0001).ConclusionsLaser peripheral iridotomy induces significant changes in the 3‐D anterior segment morphology in primary angle closure suspect patients. The Scheimpflug‐Placido disc topographer provides reproducible measurements of the iridocorneal angle and other parameters measured and hence, may become clinically useful for non‐invasive detection of potentially occludable angles. Predictors of iridocorneal angle widening after iridotomy were older age and anterior chamber volume.

English

INTRODUCTION: Glaucoma is the second leading cause of blindness worldwide & is especially common & morbidity causing among women and Asians. Glaucoma afflicts 12 million people in our country. Primary open angle glaucoma is more common in general population. However angle closure glaucoma tends to be more aggressive & visually debilitating. Inspite of being treated with iridotomy, medical & surgical management, it continues to produce excessive visual morbidity. Acute angle closure glaucoma which is vision threatening is a potentially preventable condition and hence early identification and treatment with laser peripheral iridotomy in susceptible patients is of utmost importance. AIMS AND OBJECTIVES: To study the angle morphology before and after laser peripheral iridotomy in patients with primary angle closure & primary angle closure glaucoma. METHODOLOGY: Prospective observational study to study the changes in anterior chamber angle structures before and after laser peripheral iridotomy using Ultrasound biomicroscopic technique. The study was conducted in patients presenting to the glaucoma clinic of the department of ophthalmology of Govt Rajaji Hospital, Madurai for the period of 6 months. A total of 50 patients were studied. Patients presenting with shallow angles were studied & their complete history, assessment of anterior segment which includes slit lamp examination, gonioscopy by Goldman 3 mirror goniolens, IOP measurement by applanation tonometry, fundus examination using +90D lens and standard perimetry was done. The patients were categorised as Primary angle closure or as Primary angle closure glaucoma depending on the clinical findings. Then Ultrasound biomicroscopic assessment was done prior to and after 2 weeks of laser peripheral iridotomy to measure central ACD (anterior chamber depth), AOD (angle opening distance), TIA (trabecular iris angle) & other angle parameters. Results were analysed statistically. RESULTS: Among the total studied population of 50 patients, 48% were diagnosed to have primary angle closure & remaining 52% had primary angle closure glaucoma. In the PAC group: There was a significant change in all the parameters measured. ACD (mm) changed from an average from 2.199±0.04 to2.32±0.00 with a p value of ˂ 0.001. AOD 500 (Angle opening distance mm) increased from an average of 0.106 ± 0.0 to 0.209 ± 0.0 with a p value of ˂ 0.001. Sup TIA (deg) increased from an average of 8.252±0.16 to 16.081±0.23 with a p value of ˂ 0.001. Inf TIA (deg) increased from an average of 9.125±0.04 to 16.118±0.24 with a p value of ˂ 0.001. TCPD (TRABECULAR CILIARY BODY DISTANCE mm) increased from an average of 0.745 ± 0.0 to 0.82 ± 0.01 with a p value of ˂ 0.001. IT (IRIS THICKNESS mm) increased from an average of 0.459 ± 0.01 to 0.487 ± 0.00 with a p value of ˂ 0.001 ILCD (IRIS LENS CONTACT DISTANCE mm) decreased from an average of 1.217 ± 0.05 to 1.162 ± 0.02 with a p value of ˂ 0.001. ILA (IRIS LENS ANGLE deg) ) increased from an average of 25.729 ± 0.52 to 27.754 ± 0.57 with a p value of ˂ 0.001. In the Primary angle closure glaucoma group: There was no significant change in any of the measured parameters. CONCLUSION: Among the studied population, observation in the angle characteristics showed that there was statistically significant change in the UBM parameters noted in the primary angle closure group, however no such significant change was noted in the primary angle closure glaucoma group. Hence effective strategies should be adopted in order to identify angle closure at an early stage so that they can be treated prior to development of irreversible angle closure glaucoma.

Ocular Biometric Factors and its Association with Intraocular Pressure

Aim: To study the role of ocular biometric factors like, central corneal thickness, corneal curvature, anterior chamber depth and axial length and to evaluate its association with intraocular pressure. Materials and method: The study was done at a tertiary care hospital in North India. A detailed history from all the patients was elicited and complete ocular examination like visual acuity, slit lamp examination, tonometry, fundus examination, visual field evaluation, keratometry, gonioscopy, central corneal thickness, A-scan for axial length was performed. Observation and results: A total of 800 subjects falling in sampling frame were enrolled in the study. Central corneal thickness was 600 μm in 0.7% cases. Axial length ranged from 20.1 to 33.9 with a mean of 23.02 ± 1.27 units. Anterior chamber depth was normal in 94.7%, deep in 2.2% and shallow in 3.1% cases. IOP of patients ranged from 10.1 to 37.5 mmHg. Maximum number of cases had IOP in 16-20 mmHg range (44.1%) followed by those having IOP in 12-16 mmHg range (40.1%), 20-24 mmHg range (11.4%), >24 mmHg (3.8%) and 16 mmHg) was projected as a dependent variable with central corneal thickness, axial length and anterior chamber depth as independent variables, only anterior chamber depth showed a significant association with the outcome IOP Conclusion: A significant association was found between IOP and CCT and anterior chamber depth, while we did not find a significant association between IOP and axial length.

Evaluation of anterior segment parameters in patients with Turner syndrome using Scheimpflug imaging

To compare the anterior segment parameters in patients with Turner syndrome (TS) as measured by the Pentacam HR-Scheimpflug imaging system with those of healthy control subjects. This cross-sectional prospective study included 35 patients with TS and 30 age-matched controls. Corneal topographic analysis was performed using the Pentacam HR-Scheimpflug imaging system (Oculus, Wetzlar, Germany). The power of the corneal astigmatism, mean keratometry (Km) values for the both front and back surfaces of the cornea, maximum keratometry (Kmax), central corneal thickness (CCT), corneal volume (CoV), white-to-white diameter (WTW), chamber volume (CaV), angle and anterior chamber depth (ACD) values were recorded. The mean age of TS subjects was 17.2±6.1years; of controls, 16.4±5.7years. All participants were female. There was a significant difference in the mean values of WTW (11.3±0.5mm vs 12.0±0.4mm [P<0.001]), CaV (148.4±33.5mm3 vs 191.9±27.6mm3 [P<0.001]), and ACD (2.8±0.3mm vs 3.1±0.2mm [P<0.001]) between TS versus group and the control group. The mean values of the power of the corneal astigmatism, Km values for the both front and back of the corneal surface, Kmax, CCT, CoV, and angle values were similar between groups (P>0.05 for each one). There was a reduction in CaV, ACD, and WTW measurements in TS patients compared with controls.

Anterior Segment Dimensions Following Laser Iridotomy in Acute Primary Angle Closure and Fellow Eyes

To compare the change in anterior segment morphology after laser peripheral iridotomy (LPI) in acute primary angle closure (APAC) and their fellow eyes. Prospective, fellow eye-matched case series. In this study 42 individuals with unilateral episode of APAC were enrolled and the anterior segment optical coherence tomography (ASOCT) images were obtained in both eyes at baseline and at 6weeks after LPI. A linear mixed-effects model was used to compare changes in anterior chamber and angle variables with consideration of laterality as the random effect and pupil diameter as the fixed effect. APAC eyes had smaller angle parameters (P= .013 for all), less central anterior chamber depth (cACD) (P < .001), and lower anterior chamber area (ACA) (P < .001), as well as greater lens vault (LV) (P= .007), compared with fellow eyes. LPI resulted in angle widening with a significant increase in opening distance (P < .01 for all) in both APAC and fellow eyes. cACD (P= .003) and ACA (P < .001) increased and LV (P= .002) decreased in APAC eyes. However, there was no significant change in cACD (P= .190) and LV (P= .430) in fellow eyes. In both APAC eyes and fellow eyes, iris curvature decreased after LPI (P < .001). The changes in angle parameters, ACA, and iris curvature were not significantly different between the 2 groups. In APAC eyes and their fellow eyes, LPI resulted in significant anterior chamber angle widening and increased anterior chamber area. In APAC eyes, the iris flattened, cACD deepened, and the lens shifted posteriorly after resolution of the attack. However, in fellow eyes, the increase in ACA was mainly owing to decreased iris curvature.

Anterior Chamber Changes After Implantable Collamer Lens Implantation in High Myopia Using Pentacam: A Prospective Study

IntroductionThe objective of this study was to evaluate the changes of the anterior chamber (AC) of the eye after implantable Collamer lens (ICL) implantation in high myopia by using the Pentacam.MethodsThe prospective study included 34 high myopic patients (34 eyes). All patients were treated with Visian implantable Collamer lens (ICL) (Staar Surgical Co.) implantation. The Pentacam (Oculus) was used for all cases preoperatively and 1, 3 and 6 months postoperatively. AC angle (ACA), AC volume (ACV), central AC depth (CACD), ICL vault, central corneal thickness (CCT), pupil diameter (PD), K readings and intraocular pressure (IOP) were recorded.ResultsOur study included 34 eyes of 34 patients, 20 females (59%) and 14 males (41%). Mean ACA was 36.93° ± 4.75° preoperatively, 25.17° ± 5.64° and 25.23° ± 6.05° 1 and 3 months postoperatively (p < 0.001). Mean ACV was 191.24 ± 11.18 mm3 preoperatively, 141.53 ± 16.77 and 142.11 ± 15.89 mm3 1 and 3 months postoperatively (p < 0.001). Mean CACD was 3.59 ± 0.17 mm preoperatively, 2.83 ± 0.24 mm and 2.96 ± 0.25 mm 1 and 3 months postoperatively (p < 0.001). The ICL vault decreased from 0.556 ± 0.033 mm 1 month postoperatively to 0.431 ± 0.056 mm 3 months postoperatively (p < 0.001). There were no statistically significant differences for any of the AC parameters among measurements taken 3, 6 and 12 months postoperatively. There were no statistically significant differences between preoperative and any postoperative measurements of CCT, PD and K readings.ConclusionsICL implantation for correction of high myopia leads to significant changes in the anterior chamber angle, volume and depth and insignificant changes in the pupil diameter, CCT and K readings.

Observation on the ciliary body detachment after remission of the acute attack of glaucoma

Objective To observe relevant factors and therapic efficacy of the secondary ciliary body detachment after remission of the acute attack of primary acute angle-closure glaucoma(PACG). Methods Clinical data of 82 eyes of 82 patients with PACG were collected.Seven eyes of 7 patients were determined with ciliary detachment by ultrasound biomicroscope (UBM) after remission of the acute attack. The IOP and anterior chamber depth measured with noncontact tromometer and UBM were retrospectively analyzed. Results The IOP was (62.71±8.34) mmHg (1 mmHg=0.133 kPa) and the central anterior chamber depth was (1.60±0.21) mm in eyes without ciliary body detachment at the acute attack of PACG.After remission of the acute attack the IOP was (9.71±5.06) mmHg and the central anterior chamber depth was (1.27±0.20) mm in eyes with ciliary body detachment.Seven eyes of 7 cases (8.54%) measured by UBM and B ultrasound with ciliary body detachment and without choroidal detachment.After the pilocarpine eye dropping was ceased and appropriate amount of glucocorticoid was applied, all the detached ciliary bodies reattached. Conclusion After remission of the acute attack of PACG often cause ciliary body detachment. The direct signs of ciliary detachment are ocular hypotension and shallower anterior chamber. Promptly stopping pilocarpine and the appropriate amount of glucocorticoid is an effective method. Key words: Glaucoma, angle-closure, acute; Detachment, ciliary body; Ultrasound biomicroscope

Comparison of the therapeutic effects of two surgical methods for treating primary angle closure glaucoma with cataract

Objective To study the different clinical effects between the method of peripheral iridectomy+ trabeculectomy combined with cataract extraction with small incision+ intraocular lens implantation and the method of peripheral iridectomy+ trabeculectomy combined with cataract with phacoemulsification+ intraocular lens implantation , so as to provide guidance for clinic. Methods 40 cases were randomly divided into A and B groups, and A group included 19 patients (31 eyes), while B group included 21 patients (37 eyes). A group was treated with the peripheral iridectomy+ trabeculectomy combined with cataract extraction with small incision+ intraocular lens implantation method, and B group was cured with the method of peripheral iridectomy+ trabeculectomy combined with cataract with phacoemulsification+ intraocular lens implantation method.In each group, the eye pressures, visual acuity, central anterior chamber depths of before and after treatment were compared to study the clinical effect.And after treatment, the improvement amount of eye pressure, visual acuity, central anterior chamber depths and the complication rates were compared between the two groups, so as to determine the better method. Results After treatment, the eye pressure, visual acuity, central anterior chamber depths in A group were significantly improved[(21.71±10.17)mmHg, (0.29±0.09) and (1.97±0.47)mm, t=11.12, 6.93, 17.39, all P<0.05]. The eye pressure, visual acuity, central anterior chamber depths in B group were significantly improved[(19.45±9.54)mmHg, (0.35±0.16) and (1.98±0.39)mm, t=6.52, 5.78, 17.78, all P<0.05]. After treatment, the eye pressures in A and B groups were cut down[(21.74±10.17) and (19.45±9.54)mmHg], and there was no statistical significant difference between the two groups (t=0.96, P=0.17). The visual acuity in A and B groups were improved[(0.29±0.09) and (0.35±0.16) degrees], and there was no statistically significant difference between the two groups (t=1.86, P=0.97). The central anterior chamber depths in A and B groups were improved[(1.97±0.47) and (1.98±0.39)mm], and there was no statistically significant difference between the two groups (t=0.09, P=0.54). The incidence rates of complication in A and B groups were 48.39% and 21.62%, respectively, and the difference between two groups was significant (χ2=5.44, P=0.02). Conclusion The two treatments had significant and equal clinical effects, while because of its lower incidence rate of complication, the method of peripheral iridectomy+ trabeculectomy combined with cataract with phacoemulsification+ intraocular lens implantation is more safe than the other one. Key words: Primary angle-closure glaucoma; Cataract; Small incision cataract extraction; Phacoemulsification

To study the effects of central corneal thickness, axial length, and anterior chamber depth on intraocular pressure

Purpose: The aim of the research project is to study the effects of central corneal thickness (CCT), axial length (AL), and anterior chamber (ACD) depth on intraocular pressure (IOP). Study Period: It was a cross-sectional study and was conducted from February 2015 to June 2015. Methodology: A total of 100 participants of varying age groups were selected from Qassim University clinics who had clinically normal corneas and then were divided into different groups based on their ages. All the participants had no evidence of any ocular disease and both eyes were examined in each participant. Anterior chamber depth (ACD) and CCT were measured with Pentacam (OCULUS). IOP was measured with air puff tonometer. AL was measured by A-scan ultrasonography. Results: Two hundred eyes of one hundred participants were examined. The ages of the participants ranged between 18 and 30 years. Mean age was 23.94 years with ± 2.994 standard deviations The number of emmetropes, myopes, and hypermetropes was 50, 19, and 31, respectively. The mean corneal thickness in the right eye was 541.64 μm (±34.80) and in the left eye, it was 543.46 μm (±33.65). IOP was found to increase with increased CCT and it was statistically significant (P

Anterior Segment Morphology in Primary Angle Closure Glaucoma using Ultrasound Biomicroscopy.

AimTo evaluate the configuration of the anterior chamber angle quantitatively and study the morphological changes in the eye with ultrasound biomicroscopy (UBM) in primary angle closure glaucoma (PACG) patients after laser peripheral iridotomy (LPI).Materials and methodsA total of 185 eyes of 185 PACG patients post-LPI and 126 eyes of 126 normal subjects were included in this prospective study. All subjects underwent complete ophthalmic evaluation, A-scan biometry, and UBM. The anterior segment and angle parameters were measured quantitatively and compared in both groups using Student’s t-test.ResultsThe PACG patients had shorter axial length, shallower central anterior chamber depth anterior chamber depth (ACD), and anteriorly located lens when compared with normal subjects. Trabecular iris angle (TIA) was significantly narrow (5.73 ± 7.76°) in patients with PACG when compared with normal subjects (23.75 ± 9.38°). The angle opening distance at 500 pm from scleral spur (AOD 500), trabecular-ciliary process distance (TCPD), iris-ciliary process distance (ICPD), and iris-zonule distance (IZD) were significantly shorter in patients with PACG than in normal subjects (p < 0.0001). The iris lens angle (ILA), scleral-iris angle (SIA), and scleral-ciliary process angle (SCPA) were significantly narrower in patients with PACG than in normal subjects (p < 0.0001). The iris-lens contact distance (ILCD) was greater in PACG group than in normal (p = 0.001). Plateau iris was seen in 57/185 (30.8%) of the eyes. Anterior positioned ciliary processes were seen in 130/185 eyes (70.3%) of eyes.ConclusionIn PACG patients, persistent apposition angle closure is common even after LPI, which could be due to anterior rotation of ciliary body and plateau iris and overcrowding of anterior segment due to shorter axial length and relative anterior lens position.How to cite this article: Mansoori T, Balakrishna N. Anterior Segment Morphology in Primary Angle Closure Glaucoma using Ultrasound Biomicroscopy. J Curr Glaucoma Pract 2017;11(3):86-91.

Changes in Ocular Parameters and Intraocular Lens Powers in Aging Cycloplegic Eyes

Age-related changes in lens elasticity and ciliary muscle contractility can affect how ocular parameters respond to cycloplegia, and therefore intraocular lens (IOL) power measurements calculated by formulas using anterior chamber depth (ACD), lens thickness (LT), or white-to-white (WtW) for effective lens position prediction can vary. In response, using swept-source optical biometry in prepresbyopic and presbyopic eyes, we investigated changes in ocular parameters and IOL power calculations attributable to cycloplegia. Cross-sectional study. In 38 prepresbyopic and 42 presbyopic eyes, we measured pupil diameter, radius of corneal curvature values, central corneal thickness, WtW, ACD, LT, and axial length both before and after cycloplegia. We determined IOL power calculations with the Sanders-Retzlaff-Kraff/theoretical, Holladay 2, and Haigis formulas. To pinpoint the effect of cycloplegia, we recorded refractive predictions in pre- and postdilation conditions according to the same IOL power calculations, even if postdilation IOL power calculations had changed. With cycloplegia, pupil diameter changed significantly more in presbyopic eyes (P < .001). Central corneal thickness decreased in prepresbyopic eyes (P= .048), whereas WtW increased in presbyopic eyes (P= .02). In both groups, ACD and LT changed significantly (P < .001). IOL power calculations according to the Holladay 2 formula differed in prepresbyopic eyes (P= .042), and refractive predictions with the Holladay 2 and Haigis formulas differed significantly in prepresbyopic eyes (P= .043 and P= .022, respectively). Surgeons should consider the effect of cycloplegia on refractive prediction errors and IOL power calculations determined with Haigis and Holladay 2 formulas, especially in prepresbyopic ages.

Difference between manifest and cycloplegic refraction in healthy non‐presbyopic patients

PurposeTo study the variation of objective refraction between manifest and cycloplegic conditions in healthy myopic patients younger than 40 years.MethodsSixty‐six myopic eyes of healthy patients under the age of forty years were included in this study. Manifest refraction, mean corneal power, white‐to‐white measurement, pupil diameter, central corneal thickness and anterior chamber depth weremeasured. Following the evaluation, 1% cyclopentolate was applied to induce cycloplegia and autorefractometer refraction was determined again. A statistical analysis was accomplished to investigate the relation ofthe mentioned parameters with the variation between manifest and cycloplegic refraction.ResultsTwenty‐eight eyes showed no difference between non‐cycloplegic and cycloplegic refraction. Thirty‐eight eyes presented a relevant difference (over 0.5D) between both measurements. The statistical analysis showed no differences between these two groups in age, non‐cycloplegic refraction, keratometry, white‐to‐white, central corneal thickness or anterior chamber depth. The only significant difference found between groups was the pupil diameter. Those patients with smaller pupil diameters presented greater changes in refraction. On the contrary, patients with wider pupils had negligible changes of refraction.ConclusionsAccording to our outcomes, not only hyperopic patients and children, but also myopic patients may require refraction assessment under cycloplegic conditions when autorefraction is used, since many of them show a significant modification with respect to manifest refraction. Our results show a relation between this change in autorefractometer refraction with and without cycloplegia and the pupil diameter.

Case‐finding for angle closure: the diagnostic value of simple tests for estimating limbal and central anterior chamber depth

PurposeTo evaluate the diagnostic accuracy of limbal and central anterior chamber depth measurement for detecting gonioscopically narrow anterior chamber angles (ACAs).MethodsA total of 78 subjects with narrow or open ACAs underwent an assessment of anterior chamber depth at the temporal limbus by estimating depth as a percentage of peripheral corneal thickness (van Herick test) by one examiner and just‐touching‐slit‐length measurements of the central anterior chamber depth (Smith's test) by a second examiner. Diagnostic performance was compared with (a) a gonioscopy reference standard, performed by a third examiner using the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) definition of primary angle closure and (b) a classification based on clinical opinion of occludability. All examiners were masked regarding each subject's clinical status and other test results. Sensitivity, specificity, and partial area under the receiver operating characteristic curve (AUROC) were generated.ResultsThe van Herick grading cutoff of 25% or less and ISGEO gonioscopic classification achieved 80% (95% CI 65–89) sensitivity and 92% specificity (95% CI 80–97) for narrow angle detection, with specificity reaching 97% (95% CI 87–100) for a cutoff of less than or equal to 15%. Notably, with a gonioscopic classification based on clinical opinion of occludability, van Herick (≤25%) together with Smith's test (≤2.50 mm) detected 100% of narrow angle subjects.ConclusionsThe van Herick test provides good discrimination between narrow and open angles both alone, and in combination with the measurement of central anterior chamber depth. These tests show good potential for identifying individuals who may benefit from further gonioscopic assessment in a case‐finding or screening setting.

Effects of phacoemulsification and intraocular lens implantation combined with ciliarotomy in the treatment of angle-closure glaucoma with cataract.

The aim of the present study was to examine the effects of phacoemulsification and intraocular lens implantation combined with ciliarotomy in the treatment of angle-closure glaucoma with cataract in the elderly. A total of 68 patients were consecutively selected and divided into the control group with 33 cases (48 eyes) and the observation group with 35 cases (53 eyes). Cataract surgery combined with trabeculectomy was performed on the patients in the control group and phacoemulsification cataract extraction combined with ciliarotomy was performed on the subjects in the observation group, to compare postoperative effects and complications. Following surgery, the visual acuity of patients in the two groups significantly improved, intraocular pressure decreased, and improvement of the observation group was more evident (P<0.05). Following surgery, the depth of central anterior chamber and width of chamber angle of patients in two groups was increased, and improvement of the observation group was significantly more evident (P<0.05). Additionally, the incidence of complications, including corneal swelling, shallow of anterior chamber, fibrinous exudate in iris, and filtering bleb leaking and following cataract removal, of patients in the observation group was significantly reduced compared to the control group (P<0.05). In summary, the results of the present study show that, phacoemulsification and intraocular lens implantation combined with ciliarotomy in the treatment of angle-closure glaucoma with cataract in the elderly is a safe and effective method and should be applied in the clinic.

Association between choroidal thickness and anterior chamber segment in eyes with narrow or open-angle.

To investigate the relationship between choroidal thickness and anterior chamber segment in subjects with eyes with narrow or open-angle. The subfoveal choroidal thickness was measured with enhanced depth-imaging optical coherence tomography and anterior chamber parameters were measured with ultrasound biomicroscopy in one eye of 23 subjects with open-angle eyes and 38 subjects with narrow-angle eyes. The mean age was 59.52±7.04y for narrow-angle subjects and 60.76±7.23y for open-angle subjects (P=0.514). Multivariate linear regression analysis was performed to assess the association between choroidal thickness and narrow-angle parameters. There were no differences in subfoveal choroidal thickness between open- and narrow-angle subjects (P=0.231). Anterior chamber parameters, including central anterior chamber depth, trabecular iris angle, iris thickness 500 µm from the scleral spur (IT500), and ciliary body thickness at 1 mm and 2 mm from the scleral spur (CBT1, CBT2) showed significant differences between the two groups (P<0.05). Subfoveal choroidal thickness showed negative correlation (β=-0.496, P=0.016) only with anterior chamber depth in the open-angle group and with age (β=-0.442, P=0.003) and IT500 (β=-0.399, P=0.008) in the narrow-angle group. However, subfoveal choroidal thickness was not correlated with trabecular iris angle, anterior chamber depth, ciliary body thickness, or central corneal thickness in the narrow-angle group. Choroidal thickness does not differ in the two groups and has not correlated with anterior chamber parameters in narrow-angle subjects, suggesting a lack of relationship between choroidal thickness and primary angle-closure glaucoma.

Evaluation of circumferential angle closure using iridotrabecular contact index after laser iridotomy by swept-source optical coherence tomography.

To investigate the quantitative changes of circumferential angle closure after laser iridotomy (LI) using the iridotrabecular contact (ITC) index by Swept-Source optical coherence tomography (OCT). In this prospective observational study conducted in a hospital setting, 42 eyes of 36 patients (five males, 31 females) who underwent LI were included. The mean age was 65.00±8.13years old and the diagnosis included primary angle closure (PAC, 21 eyes), PAC suspect (16 eyes) and PAC glaucoma (five eyes). Optical coherence tomography (OCT) images were obtained pre-LI and at 1week post-LI. In each image frame, the scleral spur (SS) and the ITC end-point were marked, from which the ITC index was calculated as a percentage of the angle closure across 360°. Measurements inspected before and after LI included: central anterior chamber depth (ACD), anterior chamber volume (ACV), lens vault (LV), nasal and temporal angle opening distance (AOD), angle recess area (ARA), trabecular-iris space area (TISA), trabecular-iris angle (TIA) at 500μm and 750μm from the SS and intraocular pressure (IOP). The ITC index and IOP decreased significantly after LI from 71.52±26.29 to 35.31±27.19 and from 20.64±12.72mmHg to 14.02±3.49mmHg, respectively (p<0.001 and p<0.001). Central ACD (1.94±0.31mm pre-LI) and LV (1.13±0.32mm pre-LI) did not show a significant change after LI (all p>0.05), but ACV increased significantly after LI (p<0.001). Most of the angle parameters except for nasal TIAs increased significantly after LI (all p<0.05). The ITC index from patients with shallow anterior chamber angle showed a significant decrease after LI, but part of the angle closure was not relieved after LI. Other mechanisms besides pupillary block may play a role together in causing angle closure.

Phacoemulsification combined with goniosynechialysis in the treatment of cataract with acute angle-closure glaucoma

Objective To observe the clinical efficacy of phacoemulsification combined with goniosynechialysis for cataract patients with acute primary angle-closure glaucoma. Methods From February 2010 to January 2014, 54 eyes of 54 cases with cataract and acute primary angle-closure glaucoma admitted to our department were selected in this study. All patients received phacoemulsification combined with goniosynechialysis. The visual acuity, intraocular pressure, anterior chamber depth and angle changes before and after the treatment were compared. The clinical effects of this surgical approach were analyzed. Results The visual acuities 6 months after the surgery were significantly better than those before the surgery(P<0.05), and only two eyes with age-related macular diseases had poor visual acuities less than 0.1. One day after the surgery, the intraocular pressure was (13.22±3.44) mmHg (1 mmHg=0.133 kPa). One month after the surgery, the intraocular pressure was (13.87±1.11) mmHg.The intraocular pressure of three and six months after surgery were (13.81±0.97)mmHg and(13.07±1.05)mmHg respectively. Six months after the surgery, the central and peripheral anterior chamber depth were (3.53±0.32)mm and (3.91±0.14)mm respectively, both were evidently higher than those before the surgery (P<0.05). The angle grading after the surgery were improved remarkably compared with the preoperative one(P<0.05). Corneal edemas occured in six eyes, and anterior chamber inflammation and iris fibrinoid exudations occured in four eyes. The anterior chamber of two eyes were shallow. The intraocular lens were adhered to pupil in three eyes. Conclusion Phacoemulsification combined with goniosynechialysis is safe and effective for angle-closure glaucoma. This kind of combined surgery can obviously increase the depth of the anterior chamber, improve the openness of angle, improve the vision and reduce the intraocular pressure. Key words: Glaucoma, angle-closure; Phacoemulsification; Cataract; Goniosynechialysis

The morphologic and quantitative evaluation of ocular anterior chamber parameters after laser peripheral iridotomy in primary angle-closure glaucoma eyes

Background Pentacam anterior segment analysis system(Pentacam) is more accurate in the quantitative evaluation of ocular anterior segment in primary angle-closure glaucoma (PACG) eyes than slit lamp microscope and ultrasound biomicroscope (UBM). However, its accuracy in the earlier stage of PACG before and after YAG laser peripheral iridotomy (LPI) is not fully elucidated. Objective This study was to assess the effect of YAG LPI in PACG patients with Pentacam. Methods A prospective self-controlled study was performed.Thirty-five fellow eyes (pre-clinical stage of PACG) of acute PACG and 35 fellow eyes of chronic PACG were included in the Second Hospital of Hebei Medical University from July, 2012 to December, 2013.YAG LPI was performed on the eyes, and the parameters of ocular anterior segment including central anterior chamber depth (ACD), anterior chamber volume (ACV) and peripheral anterior chamber angle (ACA) were measured and compared by Pentacam before and 1 day, 7 days, 28 days after operation.This study was approved by the Ethic Committee of the Second Hospital of Hebei Medical University and informed consent was obtained from all subjects. Results In pre-clinical stage of PACG eyes, the postoperative ACD and ACV values were increased in comparison with preoperation, showing significant differences among various time points (ACD: F=6.783, P=0.004; ACV: F=19.090, P=0.000), and no significant difference was found in ACA among different time points (F=0.153, P=0.928). In the fellow eyes of chronic PACG, the postoperative ACD and ACV values were larger than those of preoperation, with significant differences among various time points (ACD: F=21.576, P=0.000; ACV: F=47.506, P=0.000), and no significant difference was found in ACA among different time points (F=0.581, P=0.629). The change values of ACD and ACV were (0.064±0.022)mm and (27.840±4.963)mm3 in the eyes of pre-clinical stage of PACG, and those in the fellow eyes of chronic PACG were (0.047±0.020)mm and (21.000±3.278)mm3, showing significant differences between the two groups (ACD: t=2.783, P=0.008; ACV: t=5.749, P=0.000). Conclusions Pentacam allows easy, fast, automatic and non-contact quantification and three-dimension image of the anterior chamber parameters before and after YAG LPI in pre-clinical stage of PACG eyes and fellow eyes of chronic PACG.The ACD deepens and ACV increases after LPI in glaucomous eyes, especially in the pre-clinical stage of PACG eyes. Key words: Glaucoma, angle-closure/surgery; Anterior chamber/pathology; Biometry; Imaging, three-dimensional; Diagnostic techniques, ophthalmological/instrumentation; Laser therapy; Iridectomy; Pentacam anterior segment analysis system

Agreement Between Swept-Source Optical Biometry and Scheimpflug-based Topography Measurements of Anterior Segment Parameters

To estimate the agreement of anterior segment parameters between a swept-source optical biometry (IOLMaster 700; Carl Zeiss Meditec AG, Jena, Germany) and a Scheimpflug-based topography with high resolution (Pentacam HR; OCULUS, Wetzlar, Germany). Interinstrument reliability analysis. A total of 62 eyes from 62 young adults were included in the study. Average keratometry (AveK) and simulated keratometry (SimK) along 2.0-mm-ring measurements provided by Pentacam HR, keratometry readings provided by IOLMaster 700, and central corneal thickness (CCT) and anterior chamber depth (ACD) values obtained from both devices were recorded. J0 and J45 vectoral components of astigmatism were obtained using power vector analysis. Mean keratometry (Km) values of IOLMaster 700 were compared for each type of Km value from Pentacam HR, while other parameters were compared between devices. To assess the agreement between measurements of the devices, Bland-Altman analysis was performed. The Pentacam HR exhibited significantly lower Km and CCT measurements (P < .001, for all); however, no significant difference emerged in J0, J45, and ACD measurements (P= .057, P= .574, and P= .64, respectively). The mean difference between AveK, SimK 2.0mm, and the IOLMaster 700 Km was-0.20 diopter (D) and-0.14 D, respectively, while the mean difference between J0, J45, CCT, and ACD measurements was 0.07 D,-0.016 D,-5.05μm, and 0.004mm, respectively. In clinical practice, Pentacam HR and IOLMaster 700 can be used interchangeably to measure J0 and J45 vectoral components of astigmatism for SimK 2.0mm and IOLMaster keratometry values, as well as ACD and CCT measurements. However, SimK 2.0mm and AveK values can be not interchangeable, as the devices have clinical and statistical differences in measurements.

Clinical Outcomes of Laser Peripheral Iridotomy in Eyes with Primary Angle Closure Suspect and Primary Angle Closure

Background: Primary angle closure glaucoma (PACG) is a leading cause of bilateral blindness worldwide. Laser peripheral iridotomy (LPI) has been proposed as the standard prophylactic option for patients with the risk of developing the spectrum of disease, from primary angle closure suspect (PACS) toprimary angle closure (PAC) then to PACG. We aim to evaluate the effect of LPI on intraocular pressure(IOP), anterior chamber depth (ACD) and angle width, as prophylactic management in PACS and PAC.Methods: Literature search was conducted from MEDLINE database using Pubmed search engine.Inclusion criteria were all studies (interventional and observational) that reported outcomes of LPI onPACS and/or PAC eyes. Exclusion criteria were outcomes of LPI on PACG eyes.Results: There were 8 studies included in this literature review; 4 studies evaluated patients with PACS,1 study evaluated patients with PAC, while 3 studies had compared between PACS and PAC. FollowingLPI, majority of the studies showed a decrease of IOP when compared to baseline. While, 5 studiesevaluated changes of central ACD and majority of those studies indicated deepening of ACD. Fourstudies had assessed the angle width changes after LPI that revealed advancement of angle width.Conclusion: The results of this literature review showed that LPI in PACS and PAC eyes showed decrease of IOP within a specified period, the deepening of central ACD and increase of angle width.Keywords: Primary angle closure suspect, primary angle closure, laser peripheral iridotomy