Evaluation of changes of anterior segment parameters in patients with pseudoexfoliation syndrome after cataract surgery using anterior segment optical coherence tomography.

The aim of the study was to compare the anterior segment parameters after cataract surgery in pseudoexfoliation syndrome (PEX) and control eyes. We conducted a prospective comparative study of 36 eyes (PEX group), 16 eyes (PEXG group) and 46 eyes (control group) of 98 patients after phacoemulsification with intraocular lens implantation. Before surgery, 1 week, 1 month and 3 months postoperatively, anterior chamber parameters were evaluated by swept source anterior segment optical coherence tomography (AS-OCT). Anterior chamber depth (ACD), angle opening distance (AOD500/750), trabecular-iris space area (TISA500/750), trabecular-iris angle (TIA500/750) and lens vault (LV) were assessed at each study visit. Preoperatively, ACD, AOD500/750 and TISA500/750 were significantly smaller, while LV was significantly greater in PEX and PEXG eyes than in controls. 3 months postoperatively all irido-corneal parameters and ACD were significantly greater in all study groups without intergroup differences. ACD and LV significantly increased in PEX group between 1 and 3 months after surgery while being stable in control group. Relative increases in ACD, AOD500, TISA750, TIA500/750 were significantly higher in PEX and PEXG groups than in controls. Our study finds that ACD and iridocorneal parameters in AS-OCT demonstrated significantly greater relative increases 3 months after phacoemulsification in PEX and PEXG groups than in control eyes. Significantly greater deepening of anterior chamber and opening of the irido-corneal angle may be a reason for different refractive outcomes and IOP control in patients with PEX and PEXG after routine cataract surgery.

Bleb Analysis Using Anterior Segment Optical Coherence Tomography and Surgical Predictors of XEN Gel Stent.

PURPOSE: To determine the early predictors of surgical success 6 months after XEN surgery among clinical parameters, including anterior segment optical coherence tomography (AS-OCT). METHODS: A total of 31 eyes with medically uncontrolled primary open-angle glaucoma or pseudoexfoliation glaucoma was enrolled retrospectively. Using AS-OCT, XEN tip location was categorized into intraconjunctival, intratenon, or uviform at day 1 and blebs were classified into no or low, high sparse, high thick, cystic, or mixed walls at month 6. Using slit-lamp photography, blebs were classified into no or low, localized avascular, diffuse avascular, localized vascular, or diffuse vascular blebs at month 6. Surgical success was defined as an intraocular pressure (IOP) of less than 14 mm Hg. RESULTS: Intraconjunctival and intratenon locations of the tip mostly created a high sparse wall, whereas the uviform type mostly created no or low wall and no or low bleb. The uviform type was linked to pseudoexfoliation glaucoma. A high sparse wall and diffuse avascular bleb showed a lower mean IOP than a high thick wall and localized vascular bleb. In the multivariate analysis, female sex and IOP at week 1 were early predictors of surgical success (8.45 times and 33.1% per 1 mm Hg-decrease, respectively). CONCLUSIONS: Bleb evaluation using AS-OCT is valuable to correlate tip location and bleb morphology with clinical profiles, considering that a lower early postoperative IOP is linked to surgical success. TRANSLATIONAL RELEVANCE: Bleb analysis using AS-OCT on day 1 could help to predict bleb morphology after 6 months, which is important to maintain the functioning bleb in the longer term.

One-year outcomes of microshunt implantation in pseudoexfoliation glaucoma.

PURPOSE: To compare the safety and efficacy of microshunt implantation augmented with Mitomycin C in patients with pseudoexfoliation glaucoma (PEXG) and primary open-angle glaucoma (POAG). METHODS: In this retrospective, single centre, interventional study, 46 eyes of 41 patients with PEXG (20 eyes) and POAG (26 eyes) underwent microshunt implantation. Definition of failure was an intraocular pressure (IOP) lower than 5 or higher than 17mmHg on two consecutive visits, an IOP reduction lower than 20% on two consecutive visits, the need of surgical revisions or reoperations or loss of light perception. Outcome was rated as complete success if achieved without medication, otherwise as qualified success. Furthermore, postoperative complications and interventions were compared between the two groups. RESULTS: Patient demographics were similar, except for older age in the PEXG group (70.9±8.6 versus 77.6±8; p = 0.02). Mean IOP dropped from 21.5±5.8mmHg (PEXG) and 18.2±4.5mmHg (POAG) at baseline to 12.8±3.0mmHg (p<0.0001) and 12.9±4.2mmHg (p<0.0001), respectively, at one year. Mean number of medications were reduced from 2.8±1.3 to 0.3±0.8 for PEXG patients (p<0.0001) and from 2.7±1.3 to 0.3±0.8 for POAG patients (p<0.0001). At one year of follow-up 75.0% of PEXG patients achieved complete success and 80.0% qualified success. In the POAG group rates were 73.1% and 76.9%, respectively. Postoperative complications were comparable between both groups, except for higher rates of hypotony (p = 0.04) and choroidal detachment (p = 0.03) in the PEXG group. CONCLUSION: Microshunt implantation demonstrated similar efficacy results in PEXG and POAG eyes at a follow-up of 12 months. Higher rates of transient hypotony and choroidal detachment were observed in PEXG eyes.

Microstructure and Chemical Analysis in Pseudoexfoliation Syndrome.

Purpose: The aim of this study is to show the pseudoexfoliation syndrome (PES) material accumulated in the lens anterior capsule and the trace elements directly with using scanning electron microscopy (SEM) and to investigate the effect of PES materials on aqueous humor by chemical analyses.Methods: The study groups consisted of 30 patients with PES and 30 patients without PES. 0.1-0.3 mL of aqueous humor was aspirated from anterior chamber and anterior capsule sample was obtained by applying continuous curvilinear capsulorhexis. The level of selected elements (Zn, Cu, Se, Fe, Si, Al, Ca, K) were determined from aqueous humor samples via Inductively coupled plasma - optical emission spectrometry (ICP-OES) machine. The morphology and elemental distribution of anterior lens capsules were carried out via a Zeiss Sigma 300 scanning electron microscope with energy dispersive X-ray spectroscopy (semiquantitative EDX).Results: For aqueous humor, the ICP-OES results show that Cu and Zn levels is higher (p < .001, both of them) in PES group than that the obtained from control group. It was noticed that the ratio of Cu/Zn was higher (p = .008) in aqueous humor, while Cu/Se ratio was higher in both aqueous humor (p < .001) and anterior capsule (p < .001) for PES group. The SEM images show that different metal precipitates were obtained from anterior lens capsules with PES. However, there is no obvious element precipitates on the anterior lens capsules without PES.Conclusion: The results observed that the level of selected elements can be obtained at different level in both PES group and control group. Especially, if the oxidative behavior of these elements which is thought to play a role in PES formation can be clarified, new approaches will be done to evaluate the structure of PES.

Exfoliation syndrome associated with LOXL1 gene polymorphisms in a Black patient from Latin America: a case report / Síndrome de esfoliação associada a polimorfismos do gene LOXL1 em paciente negro da América Latina: relato de caso

ABSTRACT A 89-year-old Black female with a 6-year history of advanced open-angle glaucoma was referred to the Glaucoma Service of the Ophthalmology Department - Federal University of São Paulo (UNIFESP). Best-corrected visual acuity was 20/400 in the right eye and 20/60 in the left eye. Pseudoexfoliation material was observed at the iris border, angle, and the anterior lens surface. Anterior biomicroscopy revealed exfoliation material forming an evident peripheral zone and a central disc separated by a clear intermediate zone on the anterior lens surface OU. Gonioscopy showed an open-angle Sampaolesis's line and whitish material deposits OU. Fundus examination revealed a cup-to-disc ratio of 1.0 OU with peripapillary atrophy. Genetic analysis for single nucleo­tide polymorphisms of the lysyl oxidase-like 1 gene linked to exfoliation syndrome identified two such single nucleotide polymorphisms, rs1048661 and rs216524.

RESUMO Uma mulher negra de 89 anos com um histórico de seis anos de glaucoma avançado de ângulo aberto avançado foi encaminhada ao Serviço de Glaucoma do Departamento de Oftalmologia da Universidade Federal de São Paulo (UNIFESP). A acuidade visual melhor corrigida era 20/400 no olho direito e 20/60 no olho esquerdo. Material pseudo-exfoliativo foi observado na borda iriana, ângulo e superfície anterior do cristalino. A biomicroscopia de segmento anterior demonstrou material exfoliativo formando uma zona periférica evidente e um disco central separado por uma zona intermediária livre na cápsula anterior do cristalino. A gonioscopia mostrou uma linha de Sampaolesi de ângulo aberto e depósitos esbranquiçados. O exame de fundo de olho revelou disco óptico com escavação total em ambos os olhos com atrofia peripapilar. A análise genética para polimorfismos de nucleotídeo único do gene semelhante à lysyl oxidase-like 1 ligado à síndrome de esfoliação identificou dois desses polimorfismos de nucleotídeo único, rs1048661 e rs216524.

Scheimpflug Camera Measurement of Optical Density of the Corneal Epithelium, Stroma, and Endothelium in Patients with Pseudoexfoliation Syndrome.

BACKGROUND The present study evaluated the optical density of particular layers of the cornea and anterior lens capsule in patients with pseudoexfoliation syndrome (PEX). MATERIAL AND METHODS Sixty patients with cataract and PEX (mean age 76.6±5.6 years, range 62-88 years) were compared to 55 controls with cataract without PEX syndrome (mean age 76.3±6.09 years, range 62-90 years; P>0.05). The anterior segment of one eye was examined in each patient using Pentacam HR by Oculus before the planned cataract surgery. RESULTS The average optical density of the corneal epithelium, stroma, and endothelium was 25.3±6.09% and 19.9±3.41% (P<0.001), 23.1±5.5% and 19.2±3.6% (P<0.0001), and 14.6±3.4% and 12.3±2.1% (P<0.0001) in the PEX and control groups, respectively. The optical density of the anterior lens capsule was 13.6±4.2% in the PEX group and 9.74± 2.23% in the control group (P<0.0001). The average thickness of the cornea was 555 µm and 556 µm and the average optical density of endothelial cells 2240/mm² and 2323/mm² in the PEX and control groups, respectively (P<0.05). CONCLUSIONS In patients with PEX, increased optical density was observed not only in the structures with pseudoexfoliative material detectable by a slit-lamp), but also in the corneal epithelium and stroma. The increased optical density was not associated with reduced endothelial cell density or increased central cornea thickness.

Evaluation of Long-term Anatomic Changes Following Canaloplasty With Anterior Segment Spectral-domain Optical Coherence Tomography and Ultrasound Biomicroscopy.

BACKGROUND: To analyze long-term structural changes in conjunctiva, sclera and Schlemm canal (SC) with anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) following uncomplicated canaloplasty. MATERIALS AND METHODS: Fifteen patients with planned canaloplasty and no intraoperative complications were included in this prospective study. AS-OCT images were acquired at 1, 3, 6 months and at a long-term time point (20±4.9 mo) postsurgery. UBM images were acquired at 3, 6 months and long-term after canaloplasty. The surgical site was evaluated for the presence of SC, transscleral filtration, a scleral lake, and the visibility of intra-Schlemm sutures. The SC's height and width were measured at the 3 and 9 o'clock limbus position. RESULTS: Following canaloplasty, the intraocular pressure was successfully reduced from 23.43±5.52 to 12.6±1.78 mm Hg (P<0.0001) at the final control visit. Topical medication was reduced from 2.9±1.1 to 0.4±0.6 over the same period. SC's increase in height was higher than that in width at the last visit (height: +351%, P=0.0004, width: +144%, P=0.002). With the UBM the SC was easily identifiable by the reflection of the tractions sutures in 75% of the patients at the last visit. Transscleral filtration was detectable in 42% of the patients at the last visit using AS-OCT and a scleral lake was still detectable by OCT in 25% of the patients and even in 42% of the patients by UBM. CONCLUSIONS: Persisting anatomic changes of SC, a transscleral filtration and a scleral lake can be recorded by AS-OCT and UBM long-term after successful canaloplasty.

Evaluation of anterior segment parameters in patients with pseudoexfoliation syndrome using Scheimpflug imaging / Avaliação de parâmetros do segmento anterior por imagem Scheimpflug em pacientes com síndrome de pseudoexfoliação

ABSTRACT Purpose: To evaluate anterior segment parameters in patients with pseudoexfoliation syndrome (PXS) using Scheimpflug imaging. Methods: Forty-three PXS patients and 43 healthy control subjects were included in this cross-sectional study. All participants underwent a detailed ophthalmologic examination. Anterior segment parameters were measured using a Scheimpflug system. Results: Considering the PXS and control groups, the mean corneal thicknesses at the apex point (536 ± 31 and 560 ± 31 µm, respectively, p=0.001), at the center of the pupil (534 ± 31 and 558 ± 33 µm, respectively, p=0.001), and at the thinnest point (528 ± 30 and 546 ± 27 µm, respectively, p=0.005) were significantly thinner in PXS patients. Visual acuity was significantly lower (0.52 ± 0.37 versus 0.88 ± 0.23, p<0.001) and axial length was significantly longer (23.9 ± 0.70 mm versus 23.2 ± 0.90 mm, p=0.001) in the PXS eyes than in the control eyes. There were no statistically significant differences in the mean values of keratometry, anterior chamber angle, anterior chamber depth, corneal volume, and anterior chamber volume between the PXS and control eyes. Conclusions: The patients with PXS had thinner corneas, worse visual acuity, and longer axial length compared with those in the healthy controls.

RESUMO Objetivo: Avaliar os parâmetros do segmento anterior em pacientes com síndrome de pseudoexfoliação (PXS) utilizando imagens de Scheimpflug. Métodos: Quarenta e três pacientes com PXS e 43 indivíduos saudáveis foram incluídos neste estudo transversal. Todos os participantes foram submetidos ao exame oftalmológico detalhado. Parâmetros do segmento anterior foram medidos por sistema de Scheimpflug. Resultados: Considerando os grupos PXS e controle, respectivamente, as espessuras médias da espessura corneana no ápice (536 ± 31 µm e 560 ± 31 µm, p=0,001), no centro da pupila (534 ± 31 µm e 558 ± 33 µm, p=0,001), e no ponto mais fino (528 ± 30 µm e 546 ± 27 µm, p=0,005), foram significativamente mais finas em pacientes com PXS. A acuidade visual foi significativamente menor (0,52 ± 0,37 contra 0,88 ± 0,23, p<0,001) e comprimento axial foi significativamente maior (23,9 ± 0,70 milímetros contra 23,2 ± 0,90 milímetros, p=0,001) em olhos com PXS comparados com os olhos controle. Não houve diferenças estatisticamente significativas entre PXS e controle olhos em valores médios de ceratometria, ângulo da câmara anterior, profundidade da câmara anterior, volume da córnea e volume de câmara anterior. Conclusões: Os pacientes com PXS tem córneas mais finas, pior acuidade visual, e maior comprimento axial em comparação com controles saudáveis.

Biometric characteristics of eyes with exfoliation syndrome and occludable as well as open angles and eyes with primary open-angle glaucoma.

OBJECTIVE: To describe differences in axial length scan (A-scan) and ultrasound biomicroscopy (UBM) parameters in eyes with exfoliation syndrome (XFS) and occludable angles (XFSOc), XFS and open angles (XFSOp), and eyes with primary open-angle glaucoma (POAG). DESIGN: Cross-sectional descriptive study. PARTICIPANTS: Seventy-two eyes of 72 patients (mostly Caucasians) were identified through glaucoma clinics at the University of Ottawa;19 eyes had XFSOc, 31 eyes XFSOp, and 22 eyes POAG. METHODS: After a detailed ophthalmic history and examination, A-scan biometry and UBM were done to assess anterior segment parameters: central anterior chamber depth (ACD), lens thickness, trabecular meshwork-iris angle, and angle opening distance (AOD). Lens/axial length factor and the relative lens position were calculated. The above measurements were compared across the 3 groups. RESULTS: We found statistically significant differences in measurements among the groups. ACD was shallowest in eyes with XFSOc (1.88 [SD 0.07] mm), followed by XFSOp (2.37 [SD 0.05] mm), and POAG (2.64 [SD 0.08] mm). XFSOc had thicker lenses (5.28 [SD 0.09] mm) compared with the other groups: XFSOp (5.03 [SD 0.06] mm) and POAG (4.84 [SD 0.09] mm). Lens/axial length factor was highest in XFSOc (2.34 [SD 0.05] mm) versus XFSOp (2.12 [SD 0.03] mm) and POAG (2.02 [SD 0.05] mm); relative lens position was lowest in XFSOc (2.27 [SD 0.03] mm) versus XFSOp (2.31 [SD 0.02] mm) and POAG (2.36 [SD 0.03] mm). CONCLUSIONS: Eyes with XFSOc in our study demonstrated lens thickening and shallow central ACD versus eyes with XFSOp and eyes with POAG. This suggests the possibility that cataract formation and (or) zonular weakness may contribute to the development of an occludable angle in eyes with XFS.

Hemodynamic evaluation of the posterior ciliary circulation in exfoliation syndrome and exfoliation glaucoma.

BACKGROUND: Previous studies have reported impaired blood flow in the ophthalmic artery (OA) and central retinal artery (CRA) in exfoliation syndrome and exfoliation glaucoma. This study evaluates blood flow at the long and short posterior ciliary arteries (LPCA and SPCA, respectively) in these conditions. METHODS: Consecutively examined candidates for cataract surgery were included. Only one eye (OD) was included in the analyses for consistency. Patients were classified into non-glaucoma and non-exfoliation (controls), primary open angle glaucoma (POAG), exfoliation syndrome and exfoliation glaucoma groups, based on the findings of the OD. Sixty-eight patients (41 males, 60.3%) were included. Color Doppler imaging (CDI) of the nasal and temporal branches of LPCA and SPCA was performed using a 7.5 Mhz probe. The peak systolic velocity (PSV), end diastolic velocity (EDV) and resistivity index (RI) were recorded for the examined vessels. RESULTS: EDV at the LPCA was significantly lower in exfoliation syndrome and glaucoma, compared with controls and POAG respectively. EDV was significantly lower and RI was significantly higher at the SPCA in exfoliation glaucoma, compared with exfoliation, whereas respective differences were statistically not significant between controls and POAG. CONCLUSIONS: The hemodynamic impairment at the LPCA in exfoliation syndrome and glaucoma supports an association between exfoliation and ischemic stress at the anterior ocular segment.

Characterizing pseudoexfoliation syndrome through the use of ultrasound biomicroscopy.

PURPOSE: To determine the clinical utility of ultrasound biomicroscopy (UBM) in diagnosis of pseudoexfoliation (PEX) syndrome by characterizing the lens capsule and zonules before cataract surgery. SETTING: Veterans Administration Hospital, East Orange, and University of Medicine & Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey, USA. METHODS: Ultrasound biomicroscopy was performed on 10 patients clinically diagnosed with PEX syndrome. The clinical diagnosis was made by the presence of fibrillin deposits on the anterior lens capsule, lack of pigment at the pupillary ruff, and poor pharmacologic dilation. Five persons without PEX were used as controls. The thickness of the anterior lens capsule was measured in 5 locations in each eye: centrally and in the peripheral lens capsule superiorly, inferiorly, nasally, and temporally. Four measurements were taken from the zonule at the thickest point on each fiber. The UBM also found the presence or absence of nodular deposits on the zonules. RESULTS: The anterior and peripheral lens capsule in patients with PEX was thicker than that in the control group. Additionally, patients with PEX had thicker zonules than the control group and had nodular deposits present; the control group had no deposits. These differences were all significant with a 99% confidence interval. CONCLUSIONS: A thicker anterior lens capsule and lens zonule nodules were associated with PEX. These abnormalities can be visualized with the UBM to confirm the diagnosis of PEX and identify patients at risk for operative complications.

A technique for performing ultrasound biomicroscopy in the sitting and prone positions.

To develop a reliable method for performing ultrasound biomicroscopy (UBM) in the sitting and prone positions. The probe suspended from an articulated arm was removed and reattached to the arm upside-down for use in the prone position and horizontally for use in the sitting position. A latex Tono-Pen tip cover was attached to the edge of the eyecup and was placed over the transducer through the small hole on the tip of the Tono-Pen tip cover. UBM was successfully performed in the prone and sitting positions with no loss of image quality. This method can expand the ability of the UBM to examine alterations in anatomic relationships among anterior segment structures between the supine, sitting, and prone positions.

Iridolenticular contact decreases following laser iridotomy for pigment dispersion syndrome.

OBJECTIVE: To evaluate changes in anterior segment anatomy after laser iridotomy for pigment dispersion syndrome. METHODS: Ultrasound biomicroscopy was performed on 7 eyes of 7 untreated patients with reverse pupillary block and pigment dispersion syndrome. A radially oriented image with the probe perpendicular to the eye in the superior meridian was obtained before and at least 1 week after laser iridotomy in each eye. We assessed changes in angle recess area and iris-lens contact distance. RESULTS: Mean +/- SD patient age was 31.3 +/- 5.7 years and mean +/- SD refractive error was -5.0 +/- 3.9 diopters. Angle recess area (mean +/- SD, 0.78 +/- 0.28 vs 0.35 +/- 0.11 mm2; P=.001, paired t test) and iris-lens contact distance (2.05 +/- 0.28 vs 0.79 +/- 0.13 mm; P<.001) decreased following iridotomy. Central anterior chamber depth did not change. CONCLUSION: Flattening of the iris following laser iridotomy for pigment dispersion syndrome causes a decrease in iris-lens contact and angle width while lens position remains constant.

Nd:YAG laser iridotomy in pigment dispersion syndrome: an ultrasound biomicroscopic study.

AIMS: Ultrasound biomicroscopy was used to study the shape of the iris and the iridolenticular contact in pigment dispersion syndrome (PDS) eyes, to compare them with matched normal eyes, and to assess the morphological effects of laser iridotomy in PDS eyes. METHODS: 50 eyes of 50 patients suffering from PDS (group 1), and 15 normal eyes of 15 subjects matched for age and refraction (group 2), were studied by ultrasound biomicroscopy (UBM, Humphrey-Zeiss). Nd:YAG laser iridotomy was proposed to the 30 PDS patients with concave iris and 18 underwent the treatment. RESULTS: The iris was concave in 27 eyes in group 1, and three more eyes showed a concave iris during accommodation. Among normals, iris concavity was present in two eyes. The height of the iris convexity was -0.15 (0.24) mm (range -0.65 to +0.21), in the eyes of group 1, whereas it was +0.07 (0.10) mm (range -0.21 to +0.16) in group 2 (p < 0.0012). Group 1 had greater iridolenticular contact than group 2: 1.55 (0.78) mm (range 0.30-2.88) and 1.07 (0.61) (range 0.30-2.50; p = 0.0304). After laser iridotomy, only one eye still had a concave iris. Pre- and post-treatment deflections were -0.35 (0.18) mm (range -0.61 to -0.05) and +0.01 (0.06) mm (range -0.12 to +0.17), respectively (p < 0.0001). Pre- and post-treatment iridolenticular contact was 2.10 (0.65) mm (range 0.70-2.88) and 0.93 (0.38) mm (range 0.4-1.75), respectively (p < 0.0001). After laser iridotomy, the treated irises were flatter than normal (p = 0.0207), whereas the iridolenticular contact was not significantly different. CONCLUSIONS: Laser iridotomy can restore a normal iris shape and iridolenticular contact in eyes suffering from PDS.

The role of YAG-laser iridotomy in pigment dispersion syndrome.

We determined iris configuration and posterior-chamber depth before and after YAG-laser iridotomy in 20 eyes with pigment dispersion syndrome using high-resolution ultrasound and measured the intraocular pressure after a mean of 9.1 months. The iris configuration and posterior-chamber depth of our patients were compared with those of an age- and refraction-matched control group of 20 eyes without pigment dispersion. In the patient group, 8 eyes had a concave iris configuration with shallow posterior chambers and 12 eyes had planar irides. In the former group the posterior-chamber depth increased significantly after treatment. In the latter group it did not change. In the normal control group, three subjects also had concave irides. There was a significant correlation between posterior-chamber depth and refraction in patients with pigment dispersion syndrome, but not in the normal control group. After the follow-up period the intraocular pressure of treated eyes was not significantly lower than that of untreated eyes. Iris concavity can also occur in normal individuals and may therefore be only a pathogenetic cofactor in the pigment dispersion syndrome. Laser iridotomy proved to flatten irides but did not significantly decrease the intraocular pressure.

Accommodation and iridotomy in the pigment dispersion syndrome.

BACKGROUND AND OBJECTIVE: Iris concavity has been noted in pigment dispersion syndrome, and could have a role in producing iris-zonule contact. Iris concavity is most likely caused by a relative increase in anterior chamber pressure. The method by which this occurs remains speculative. The authors used ultrasound biomicroscopy to examine the role of accommodation in producing iris concavity and to document changes that occur following iridotomy. PATIENTS AND METHODS: Thirteen patients with clinically diagnosed pigmentary dispersion and pigmentary glaucoma underwent accommodation studies while being continuously imaged with ultrasound biomicroscopy. Anterior chamber depths were measured and iris configuration noted on distance and near fixation. These studies were repeated in 6 patients following laser iridotomy. RESULTS: All patients showed a decrease in anterior chamber depth with accommodation. Ten patients had a planar iris configuration on distance fixation and 3 concave. Eleven of 13 patients showed increased concavity of the iris on near fixation as compared with distance fixation. Following iridotomy in 6 patients, the iris showed a planar configuration that remained unchanged on near fixation. CONCLUSION: Accommodation increases iris concavity in some patients with pigment dispersion syndrome. The most likely explanation is an accommodation-induced relative increase in anterior chamber pressure secondary to anterior movement of the lens surface. Iridotomy prevents change in the iris profile with accommodation.

Ultrasound biomicroscopy in pigment dispersion syndrome.

PURPOSE: To examine the positional relations of the iris, lens, ciliary processes, and zonules in eyes with the pigment dispersion syndrome (PDS). METHODS: High-resolution, anterior segment ultrasound biomicroscopy was performed on 16 untreated eyes of 11 patients with PDS. Scanning was repeated on four eyes after miotic treatment and four eyes after laser iridotomy. RESULTS: Mid-peripheral iris concavity could be demonstrated in 56%, irido-zonular contact in 25%, and irido-ciliary process contact in 75% of untreated eyes with PDS. Repeat scanning after laser iridotomy or pilocarpine therapy showed resolution of the iris concavity and irido-zonular contact in all eyes receiving these therapies. Irido-ciliary process contact persisted in some eyes. CONCLUSION: The authors' findings demonstrate the structural relations among the iris, lens, zonules, and ciliary processes in vivo that characterize the PDS. Miotic therapy and laser iridotomy eliminate the iris concavity in all patients with this finding, supporting the hypothesis of reverse pupillary block. Irido-ciliary process contact may be another mechanism causing release of pigment. This issue merits further clinical and histologic study.