Bowing Of Iris Research Articles

Endodiathermal Tautening of Floppy or Irregular Iris in Endothelial Keratoplasty (Iridodiathermy).

Floppy or irregular irides may be seen during endothelial keratoplasty in complex cases or in eyes with damaged irides and may cause uneven air fill, retro-pupillary air escape, anterior bowing of iris, forward movement of lens-iris diaphragm, shallowing of anterior chamber (AC), bellowing and floppiness of iris, uneven AC depth, difficulty in inserting and opening graft, iris trauma, intraoperative bleeding, and iridodialysis. We present a technique of iridodiathermy for tautening and flattening such irides. With continuous irrigation using AC maintainer, the bipolar endodiathermy probe tip is applied in localized spots to midperipheral iris in the affected area with power and duration adjusted to induce mild localized shrinkage and tightening of iris stroma. Such iris tautening decreases its floppiness and prevents anterior bowing, excessive mobility, irido-corneal touch, and peripheral anterior synechiae formation. It provides a stable AC with regular depth and improved, uniform, and nonmigratory air fill, thus decreasing intraoperative challenges.

Ocular morphologic traits in the American Cocker Spaniel may confer primary angle closure glaucoma susceptibility

Acute primary angle closure glaucoma is a potentially blinding ophthalmic emergency requiring prompt treatment to lower the elevated intraocular pressure in humans and dogs. The PACG in most of canine breeds is epidemiologically similar to humans with older and female patients overrepresented with the condition. The American Cocker Spaniel (ACS) is among the most common breeds observed with PACG development in dogs. This study initially sought to identify genetic risk factors to explain the high prevalence of PACG in ACSs by using a case–control breed-matched genome-wide association study. However, the GWAS failed to identify candidate loci associated with PACG in this breed. This study then assessed intrinsic ocular morphologic traits that may relate to PACG susceptibility in this breed. Normal ACSs without glaucoma have a crowded anterior ocular segment and narrow iridocorneal angle and ciliary cleft, which is consistent with anatomical risk factors identified in humans. The ACSs showed unique features consisting of posterior bowing of iris and longer iridolenticular contact, which mirrors reverse pupillary block and pigment dispersion syndrome in humans. The ACS could hold potential to serve as an animal model of naturally occurring PACG in humans.

Biometric and Structural Ocular Manifestations of Anterior Megalophthalmos.

ObjectiveThe aim of this study was to examine the biometric ocular manifestations and structural ocular features of anterior megalophthalmos (AM).MethodsFifteen patients with AM (30 eyes) from the Eye & ENT Hospital of Fudan University were included. The age-matched control group consisted of 30 participants (30 eyes) who underwent Pentacam HR and IOLMaster 700 measurements for one normal eye. Data on demographics, biometric manifestations, and genotypes were carefully compared.ResultsA total of 15 patients with AM and 30 control patients were enrolled. There were no differences in age (37.27 ± 19.1 vs. 31.43 ± 19.69 years, P = 0.249) between these two groups. AM eyes were characterized by premature cataracts (11/30, 36.67%) and zonular weakness with lens subluxation (22/30, 73.33%) compared with the control group. Notably, 20 of the 30 AM eyes (66.67%) had significant posterior iris bowing, and 16 of the 30 AM eyes (53.33%) showed an enlarged ciliary ring on ultrasound biomicroscopy (UBM). Mean corneal curvature was lower in the AM eyes (42.01 ± 2.06 D vs. 43.14 ± 1.38 D, P = 0.023). There was no significant difference in corneal pachymetry and central endothelial cell count between the AM and control groups. Significant differences were found in terms of the anterior chamber and white-to-white (WTW) among the Pentacam HR and IOLMaster 700 in patients with AM (P < 0.05). The difference was 0.53 ± 0.48 mm and 0.36 ± 0.14 mm, respectively (P < 0.001).ConclusionThe results of this cohort study conclude the biometric and structural ocular manifestations in Chinese cohorts. Posterior iris bowing (66.67%) and lens subluxation (73.33%) are the most characteristic findings in patients with AM with anatomical abnormalities of megalocornea and a deep anterior chamber, although corneal biometric manifestations of AM included flatter cornea and lower total corneal astigmatism. The knowledge of ocular manifestations of AM is important for diagnosis and preparation for the operation in advance to avoid intraoperative and postoperative complications. Significant differences were found in the anterior chamber and WTW values between the Pentacam HR and IOLMaster 700. Thus, we suggest that various examinations should be carefully considered before determining an AM diagnosis.

Comparison of anterior chamber angle parameters and iris structure of juvenile open-angle glaucoma and pigmentary glaucoma.

Purpose:To compare the quantitative measurements of the anterior chamber angle (ACA) and iris parameters in patients with juvenile open-angle glaucoma (JOAG), pigmentary glaucoma (PG), and healthy controls using anterior segment optical coherence tomography (AS-OCT).Methods:This was a retrospective, cross-sectional study of 25 eyes with JOAG, 25 eyes with PG, and 25 control eyes. Anterior chamber depth, angle-opening distance 500 and 750, trabecular–iris space 500 and 750, scleral spur angle, iris thickness (IT, measured at the thickest part), and iris bowing were obtained using AS-OCT (Visante” OCT 3.0 Model 1000, Carl Zeiss Meditec, Inc).Results:The quantitative ACA parameters were found to be significantly higher in JOAG and PG patients compared to healthy controls (P < 0.001); there was no significant difference between the eyes with JOAG and PG (P > 0.05). In eyes with JOAG and PG, there was significantly backward bowing of the iris in temporal and nasal angles compared to control subjects (P < 0.001). Median iris bowing was not significantly different between the patients with JOAG and PG (P > 0.05). The temporal and nasal angle iris thickness were significantly thinner in eyes with JOAG than the eyes with PG (P < 0.001) and age-matched control subjects (P < 0.001). The median IT did not differ between the patients with PG and control subjects (P > 0.05). In patients with JOAG, the intraocular pressure (IOP) was inversely correlated with IT (r = -0.43, P < 0.05).Conclusion:AS-OCT provided quantitative data on the ACA and iris parameters in JOAG and PG. The evaluation of the ACA and iris structures using AS-OCT revealed higher ACA measurements and posterior bowing of the iris in patients with JOAG and PG. Furthermore, the patients with JOAG were found to have thinner IT than the ones with PG and healthy controls.

Effects of Nd-YAG Laser iridotomy on anterior segment measurements in pigment dispersion syndrome and ocular hypertension

To compare the anterior segment optical coherence tomography (AS-OCT) measurements of eyes with pigment dispersion syndrome (PDS) and ocular hypertension (OHT) before and after neodymium:yttrium-aluminum-garnet (Nd:YAG) laser peripheral iridotomy (LPI). A total of 23 eyes of 23 patients with PDS and OHT with features of PDS were included in this retrospective study. All of the eyes with PDS and OHT were examined by AS-OCT before and after Nd:YAG LPI. Anterior chamber depth, angle opening distance 500, angle opening distance 750, trabecular iris space 500, trabecular iris space 750 and scleral spur angle, iris bowing and iris shape were measured with AS-OCT by the same examiner. The differences in all parameters before and after Nd:YAG LPI were statistically significant. Iris configuration was concave in all eyes prior to iridotomy. After Nd:YAG laser iridotomy, the iris configuration became convex in 7 eyes, flat in 9 eyes and remained concave in 7 eyes. Nd:YAG laser peripheral iridotomy is an effective method for reversing the iris concavity and iris bowing in pigment dispersion syndrome.

Clock position-based iris bow configuration after laser peripheral iridotomy in Chinese angle closure eyes: a swept source optical coherence tomography study.

To determine how many measurements should be evaluated to determine the iris bow and evaluate changes of iris bow at 12 clock positions after LPI in primary angle closure eyes. A total of 93 primary angle closure eyes in 93 Chinese patients were enrolled. Anterior iris bowing was evaluated at 12 clock positions and 4 clock positions (3, 6, 9, and 12 o'clock) before, 1 week and 3 months after LPI using swept source optical coherence tomography. At baseline, almost all of the eyes exhibited an iris bow when measured using 12 clock positions, consistent with results obtained from measurements at 4 clock positions (Cronbach's alpha = 0.99). LPI caused a relative unified change in all of the clock positions (Cronbach's alpha = 0.91) except the LPI site. After LPI, there was no significant difference between 12 and 4 clock position measurements for the iris bow (both p > 0.05), with ~34.1% vs. 33% of the patients remained iris bow at 1 week and 34% vs. 31.9% of the patients remained iris bow at 3 months. However, the coexisting iris bow configuration was more common when measured using 4 clock positions (16.5% vs. 3.3% at 1 week and 25.5% vs. 10.6% at 3 months). There was excellent consistency when measuring the iris bow at 4 or 12 clock positions. LPI caused a relatively unified iris bow change at 12 clock positions, and a single LPI relieved only ~2/3 of the iris bow configurations.

Outcomes of phacoemulsification in previously vitrectomized eyes

Aim: To describe and determine the intraoperative and postoperative complications stemming from technical difficulties and anatomical aspects of patients undergoing phacoemulsification after pars plana vitrectomy (PPV). Materials and Methods: In this prospective study, thirty individual eyes who presented with cataract in a previously vitrectomized eye were analyzed. The indications for PPV, operative details of PPV, and postoperative complications were noted. The best-corrected visual acuity after vitrectomy, type of lens opacity that developed following PPV, visual acuity immediately prior to cataract surgery, duration between PPV and subsequent cataract extraction, estimated intraocular lens (IOL) power, formula used for calculating the IOL power, IOL type, intraoperative complications, best final visual acuity following phacoemulsification, and finally the incidence of neodymium-doped yttrium aluminum garnet capsulotomy were noted. Statistical Analysis: SPSS for Windows, version 11.0.1, and Microsoft Excel 2007 were used. Chi-square test was used to compare complication rates. Results: Overall 86% of the eyes had improved visual acuity post cataract surgery, 11% remained the same, and 3% of it worsened. Intraoperatively, small pupil, deepening of the anterior chamber, bowing of iris–lens diaphragm, difficulty in capsulorrhexis, and presence of posterior-capsular plaque were noted. Posterior-capsule opacification was the most common late postoperative complication. Conclusion: Although challenging, with prior knowledge regarding vitrectomized eyes, such cases can be performed safely and complication rates are acceptably low.

Outcome of Single-piece Intraocular Lens Sulcus Implantation following Posterior Capsular Rupture during Phacoemulsification.

Purpose:To assess the safety and outcome of single-piece posterior chamber intraocular lens (PC-IOL) implantation in the ciliary sulcus following posterior capsular rupture during cataract surgery.Methods:Patients with posterior capsular rupture during cataract surgery with a single-piece acrylic IOL implanted into the ciliary sulcus were studied. Complete ocular examinations were performed after 6 months postoperatively.Results:Twenty-four eyes were included. Mean follow-up duration was 8.33 ± 2.33 months. There was no significant difference between preoperative and postoperative keratometric cylinder or intraocular pressure. Visual acuity of 87.50% of patients was ≥20/40 after surgery. Complications included foveopathy (10 eyes), iris transillumination defect (4 eyes), iris chafing (2 eyes), pigmented keratic precipitate (KP) (4 eyes), clinical IOL tilt (6 eyes), endothelial pigment dusting (14 eyes), IOL pigment dusting (17 eyes), iris bowing (6 eyes), IOL decentration (4 eyes), and IOL tilt detected with ultrasonography biomicroscopy (UBM) (4 eyes). IOL pigment dusting was significantly higher in eyes with short axial lengths, high IOL power, small sulcus-to-sulcus (STS) diameter, large STS IOL diameter mismatch, and small anterior chamber depth and angle. Significant relationships were observed between pigmented KP with small STS diameter and large STS IOL diameter mismatch, UBM and clinical IOL tilt with large anterior chamber depth and between iris transillumination defect and STS IOL diameter mismatch.Conclusion:This implantation is associated with higher incidence of complications. Single-piece acrylic IOLs are not designed for sulcus implantation. However, they may be used in eyes with longer axial length if the 3-piece IOL is not available.

Determinants of pupil diameters and pupil dynamics in an adult Chinese population.

To investigate the determinants of pupil diameter (PD), amplitude of pupil diameter change (PD-change) and speed of pupil constriction (SPC) using video anterior segment optical coherence tomography (AS-OCT) in a population-based sample of Chinese adults. Chinese adults aged 40 to 80years who were free from glaucoma were consecutively recruited from the population-based Singapore Chinese Eye Study. The SPC was measured by AS-OCT videography. Univariate and multivariate analyses were performed to examine the effects of demographic and ocular biometric factors (e.g., axial length [AL], anterior chamber depth [ACD], baseline PD, iris thickness at the area of the dilator muscle [ITDMR], iris area [IA], and iris bowing [IB]) on SPC, PD, and PD-change. A total of 266/302 (89.5%) AS-OCT videos of eligible eyes were available for analysis. Among these subjects, 64.3% were women, and the mean age (± standard deviation [SD]) was 56 ± 8.3years. SPC was not associated with sex. In multiple regression analyses, SPC was independently associated with baseline PD (β = 0.116, p = 0.006). Baseline PD was independently associated with ACD (β = 0.341, p < 0.001), TISA 500 (β = -4.513, p < 0.001), IA (β = -2.796, p < 0.001), and ITDMR (β = 6.573, p < 0.001). PD-change was independently associated with ACD (β = 0.256, p < 0.001), IA (β = -1.507, p < 0.001), IB (β = 0.630, p = 0.011), and ITDMR (β = 3.124, p < 0.001). Among normal eyes in an adult Chinese population, SPC was associated with larger baseline PD. Larger baseline PD and greater PD change form dark to light were associated with greater ACD, with smaller IA and thicker ITDMR.

Anterior segment optical coherence tomography documentation of Reverse Pupillary Block -A case of Pigment Dispersion Syndrome in a 10 year Old Child

We report a 10-year-old boy with unusually dense, bilateral central posterior capsule pigmentation associated with the characteristic clinical features of pigment dispersion syndrome, including Krukenberg’s spindle and dense trabecular pigmentation in both eyes. There was no history of trauma , laser or intraocular surgeries . The presence of posterior or backward bowing of iris suggested a reverse pupillary block mechanism of pigment dispersion syndrome. Nd Yag laser peripheral iridotomy was performed in both eyes to relieve reverse pupillary block. Anterior segment optical coherence tomography (AS-OCT) showed reversal of iris concavity after laser iridotomy.

Physical Factors Affecting Outflow Facility Measurements in Mice.

Mice are commonly used to study conventional outflow physiology. This study examined how physical factors (hydration, temperature, and anterior chamber [AC] deepening) influence ocular perfusion measurements in mice. Outflow facility (C) and pressure-independent outflow (Fu) were assessed by multilevel constant pressure perfusion of enucleated eyes from C57BL/6 mice. To examine the effect of hydration, seven eyes were perfused at room temperature, either immersed to the limbus in saline and covered with wet tissue paper or exposed to room air. Temperature effects were examined in 12 eyes immersed in saline at 20 °C or 35 °C. Anterior chamber deepening was examined in 10 eyes with the cannula tip placed in the anterior versus posterior chamber (PC). Posterior bowing of the iris (AC deepening) was visualized by three-dimensional histology in perfusion-fixed C57BL/6 eyes and by spectral-domain optical coherence tomography in living CD1 mice. Exposure to room air did not significantly affect C, but led to a nonzero Fu that was significantly reduced upon immersion in saline. Increasing temperature from 20 °C to 35 °C increased C by 2.5-fold, more than could be explained by viscosity changes alone (1.4-fold). Perfusion via the AC, but not the PC, led to posterior iris bowing and increased outflow. Insufficient hydration contributes to the appearance of pressure-independent outflow in enucleated mouse eyes. Despite the large lens, AC deepening may artifactually increase outflow in mice. Temperature-dependent metabolic processes appear to influence conventional outflow regulation. Physical factors should be carefully controlled in any outflow studies involving mice.

Anterior Segment Characteristics of Fuchs Uveitis Syndrome

Purpose: To evaluate the differences in the biometric parameters of the anterior segment in Fuchs' uveitis syndrome (FUS).Methods: 30 eyes of 15 consecutive patients with unilateral FUS were examined. Anterior segment parameters were measured by rotating Scheimpflug imaging camera. Central endothelial cell count was measured by noncontact specular microscopy.Results: The central cornea was thinner (p < 0.001), the iridocorneal angle was significantly larger (p < 0.010), anterior chamber depth was deeper in the eyes with FUS (p < 0.006). The iris bowing was different between the affected eye and the healthy eye. The mean endothelial cell density of eyes with FUS was significantly lower than control eyes (p < 0.001).Conclusions: Scheimpflug imaging method is a useful tool to analyze the anterior segment parameters in FUS. Endothelial cell loss, as well as decreased percentage of endothelial hexagonal cells, is obtained by noncontact specular microscopy in patients with FUS.

Ultrasound Biomicroscopy and Scheimpflug Imaging in Anterior Megalophthalmos: Changes Seen after Cataract Surgery.

Purpose. With this report we describe ultrasound biomicroscopic (UBM) findings in a patient with anterior megalophthalmos before and after undergoing phacoemulsification with posterior chamber intraocular lens implantation. Methods. Phacoemulsification was carried out for nuclear sclerosis in both eyes of a patient diagnosed with anterior megalophthalmos. The patient was subjected to detailed ophthalmic examination including ultrasound biomicroscopy and Scheimpflug imaging prior to and after surgery. Preoperative ultrasound biomicroscopy revealed a deep anterior chamber with posterior bowing of the midperipheral iris in both eyes. The ciliary processes were inserted on the posterior surface of the iris. UBM was repeated postoperatively as well. Results. Phacoemulsification and posterior chamber intraocular lens implantation (IOL) were carried out successfully in both eyes. The IOLs were well centered and captured within the anterior capsulorhexis. The anterior chambers were hyperdeep, 6.24 mm (OD) and 6.08 mm (OS), respectively. The posterior bowing of the midperipheral iris was absent, with the iris having a more flat profile. Conclusion. UBM findings in anterior megalophthalmos seemed to partially resolve after cataract surgery. The anterior chamber deepens appreciably as well.

Bilateral Simultaneous Angle-closure Glaucoma Associated With Septic Condition of Korean Hemorrhagic Fever (KHF)

To report a case of bilateral simultaneous angle-closure glaucoma caused by septic condition of Korean hemorrhagic fever. A 62-year-old man visited our emergency center with signs of sepsis (fever, leukocytosis, and oliguria). After 4 days of hospitalization, the patient reported blurred vision. Upon ophthalmologic examination, elevated intraocular pressure, edematous cornea, closed anterior chamber angle, and shallow anterior chamber without iris bowing were found in both eyes in slit-lamp examination and in Pentacam (Oculus, Wetzlar, Germany) Scheimpflug images. Bilateral choroidal effusion was observed on an ultrasound B scan as well. The serologic test for anti-hantaan virus immunoglobulin G (IgG) was positive. Along with the sepsis treatment, intravenous hyperosmotic agent, antiglaucoma eye drops, and 1% atropine eye drop were administered immediately. To control the choroidal effusion, systemic steroid was also administered. After 4 months, anterior chamber depth and choroidal effusion were normalized. Systemic causes should be considered in patients with bilateral angle-closure glaucoma, and Korean hemorrhagic fever can be one of the causes in endemic areas.

Analysis of iris structure and iridocorneal angle parameters with anterior segment optical coherence tomography in Fuchs’ uveitis syndrome

To evaluate the differences in the biometric parameters of iridocorneal angle and iris structure measured by anterior segment optical coherence tomography (AS-OCT) in Fuchs' uveitis syndrome (FUS). Seventy-six eyes of 38 consecutive patients with the diagnosis of unilateral FUS were recruited into this prospective, cross-sectional and comparative study. After a complete ocular examination, anterior segment biometric parameters were measured by Visante(®) AS-OCT. All parameters were compared between the two eyes of each patient statistically. The mean age of the 38 subjects was 32.5 ± 7.5 years (18 female and 20 male). The mean visual acuity was lower in eyes with FUS (0.55 ± 0.31) than in healthy eyes (0.93 ± 0.17). The central corneal thickness did not differ significantly between eyes. All iridocorneal angle parameters (angle-opening distance 500 and 750, scleral spur angle, trabecular-iris space (TISA) 500 and 750) except TISA 500 in temporal quadrant were significantly larger in eyes with FUS than in healthy eyes. Anterior chamber depth was deeper in the eyes with FUS than in the unaffected eyes. With regard to iris measurements, iris thickness in the thickest part, iris bowing and iris shape were all statistically different between the affected eye and the healthy eye in individual patients with FUS. However, no statistically significant differences were evident in iris thickness 500 μm, thickness in the middle and iris length. There were significant difference in iris shape between the two eyes of patients with glaucoma. AS-OCT as an imaging method provides us with many informative resultsin the analysis of anterior segment parameters in FUS.

The effect of topical latanoprost on anterior segment anatomic relationships in normal dogs

Topical latanoprost 0.005% is commonly used in dogs with primary angle closure glaucoma (PACG), and marked miosis has been reported in the literature. To further explore the effect of topical latanoprost on anterior segment anatomy, we performed iridocorneal angle biometrics in normal beagle dogs. Thirty-five normal female beagle dogs were assessed using anterior segment optical coherence tomography (AS-OCT). One eye of each dog was scanned with the AS-OCT in the superotemporal quadrant. One drop of latanoprost 0.005% was applied topically, and the OCT scan was repeated 30min later. Images were imported into ImageJ, and pupil diameter, anterior chamber angle, angle opening distance, angle recess area (ARA), anterior chamber hemifield, and anterior chamber depth were measured. A single drop of latanoprost resulted in marked miosis, anterior bowing of the peripheral iris, narrowing of the iridocorneal angle, and shallowing of the anterior chamber. The anterior segment parameters demonstrated a significant reduction (P-value≤0.001) from baseline following latanoprost with the exception of the ARA (P=0.07). Latanoprost significantly decreases pupil diameter and narrows the iridocorneal angle in normal female beagle dogs. Therefore, the utility of latanoprost as a prophylactic treatment for PACG in fellow eyes may be limited. Studies using quantitative iridocorneal angle measurements in goniodysgenic dogs are warranted to understand the changes in iridocorneal angle morphology that occur in PACG in response to topical application of latanoprost.

The Posterior Location of the Dilator Muscle Induces Anterior Iris Bowing during Dilation, Even in the Absence of Pupillary Block

To examine the effect of the posterior location of the dilator on iris anterior curvature during dilation. An in vivo human study, an ex vivo porcine experiment, and an in silico computational model were performed in parallel. Iris anterior curvature was measured in vivo before and after dilation by time-domain slit lamp optical coherence tomography (SL-OCT). All patients (n = 7) had undergone laser peripheral iridotomy to eliminate any pupillary block due to primary angle-closure glaucoma. In the ex vivo experiments, isolated porcine irides (n = 30) were secured at the periphery and immersed in an oxygenated Krebs-Ringer buffer. Dilation was induced pharmaceutically by the addition of 2.5% phenylephrine and 1% tropicamide. An in-house optical coherence tomography (OCT) system was used to obtain iris images before and after dilation. A finite element model was also developed based on typical geometry of the iris from the initial OCT image. The iris was modeled as a neo-Hookean solid, and the active muscle component was applied only to the region specified as the dilator. An increase in curvature and a decrease in chord length after dilation were observed in both experiments. In both the in vivo and ex vivo experiments, the curvature-to-chord length ratio increased significantly during dilation. Computer simulations agreed well with the experimental results only when the proper anatomic position of dilator was used. The posterior location of the dilator contributes to the anterior iris bowing via a nonpupillary block dependent mechanism.

Use of optical coherence tomography in the diagnosis and management of uveitis.

Regatieri, Caio V. MD, PhD; Alwassia, Ahmad MD; Zhang, Jason Y. MD; Vora, Robin MD; Duker, Jay S. MD Author Information

Factors Influencing Laser Peripheral Iridotomy Outcomes in White Eyes

To determine the pre-laser anterior segment optical coherence tomography (AS-OCT) features in White eyes which may predict the outcome after laser peripheral iridotomy (PI). Consecutive White patients who underwent laser PI at Capital Eye Specialists over a 25-month period (November 2007 to November 2009) were identified, and the AS-OCT images of the temporal and nasal angles (in light and dark) before laser were analyzed. The PI was considered unsuccessful if there was still iridotrabecular apposition in the dark in ≥2 quadrants at follow up. The parameters studied were anterior chamber depth, trabecular-iris angle (TIA), angle opening distance (AOD), trabecular-iris space area, trabecular-iris contact length (TICL), iris thickness, and maximum iris bow height (MIBH). Images of 71 eyes (71 patients) were assessed. The mean age at laser PI was 60.3 (±10.0) years. The mean time from laser PI to the follow-up AS-OCT scan was 5.92 (±3.22) weeks. The TIA 500 (P=0.002 temporal; P=0.024 nasal), AOD 500 (P=0.004 temporal; P=0.022 nasal), and TICL (P<0.001 temporal; P=0.013 nasal) in light were significantly different between the successful and unsuccessful groups. The MIBH in light was significant temporally (P=0.021) and approached significance nasally (P=0.052). Iris thickness measurements demonstrated no statistical significance. An unsuccessful PI outcome is associated with pre-laser greater angle closure (decreased TIA 500 and AOD 500, increased TICL) and less anterior iris bowing (decreased MIBH) in light conditions in the temporal and nasal angles.

Pigment dispersion secondary to anterior chamber angle recession

Dear Editor: Irido-zonular and/or -lenticular disruption, mostly due to posterior bowing of the iris, is believed to be the mechanism of primary pigment dispersion syndrome (PDS). Characteristic findings of PDS include Krukenberg spindle, homogenous trabecular meshwork (TM) pigmentation, and spoke-like mid-peripheral iris transillumination defects [1–5]. Primary PDS usually affects bilateral eyes, although the morbidity and manifestations may be asymmetric. Herein, we report an unusual case of monocular pigment dispersion secondary to traumatic anterior chamber angle recession. A 33-year-old male complained of blurred vision and distending pain in his right eye for more than 1 year. He sustained blunt ocular trauma by a wooden stick 10 years prior. He had no family history of either glaucoma or PDS. On admission, his visual acuity was 20/200 OD and 20/20 OS. A Krukenberg spindle was discerned in his right eye (Fig. 1a), along with posterior bowing of the mid-peripheral iris. A Zentmayer ring was visualized on the rear surface of the crystalline lens. Homogenous heavy TM pigmentation and 270o of anterior chamber (AC) angle recession were revealed on gonioscopy (Fig. 1b). Spoke-like iris transillumination defects were not seen. His left eye was unremarkable on both biomicroscopy and gonioscopy, with minimal TM pigmentation and flat iris configuration (Fig. 1c). The vertical cup/disc ratio was 0.9 OD and 0.3 OS. The intraocular pressure (IOP) was 52 OD and 17 OS. Refraction revealed −0.25 diopters in both eyes. Humphrey visual field analysis showed inferior arcuate scotoma in the right eye and normal field in the left. Ultrasound biomicroscopy (UBM) revealed posterior bowing of the iris and irido-zonular and -lenticular contact in the right eye (Fig. 1d), and flat iris in the left. The patient underwent trabeculectomy for pigmentary glaucoma in his right eye, with postoperative IOP in the teens during 6 years of follow-up. The iris became flat, and no more pigment dispersion was discerned after the surgery. Visual field deterioration was not detected with Humphrey visual field analysis postoperatively. The left eye did not show any signs of pigment dispersion or other ocular disorders after 6 years of surveillance. Pigment dispersion may occur after ocular trauma, intraocular lens implantation, iritis, and so on [1, 4, 6]. However, such secondary pigment dispersion differs from primary PDS, in that the former usually does not have Krukenberg spindle and iris transillumination defects. Krukenberg spindle is more likely to be the result of continuous pigment shedding like primary PDS, which is secondary to irido-zonular contact. The typical appearance This manuscript has not been published or submitted for publication elsewhere. We certify that all applicable institutional and governmental regulations concerning the ethical use of human subjects were followed during this research. The authors have full control of the primary data, and they agree to allow Graefe’s Archive for Clinical and Experimental Ophthalmology to review their data if requested.