Transillumination Defects Research Articles

Clinical characteristics of pigment dispersion syndrome in Chinese patients

To report clinical findings and characteristics of pigment dispersion syndrome (PDS) in Chinese patients. PDS suspects with any one of the following signs: corneal endothelial pigmentation, iris transillumination defects (ITDs), pigment granule dusting on anterior iris surface, posterior iris bowing, trabecular meshwork (TM) pigmentation, and lenticular or zonular pigmentation were evaluated for PDS at the glaucoma specialty clinic at Beijing Tongren Eye Centre. Diagnosis of PDS required at least two of the following signs: Krukenberg spindle, moderate-to-heavy TM pigmentation (>or=Scheie II) and any degree of lenticular and/or zonular pigmentation. Eighteen patients (12 males and six females) were identified as having PDS during a 1-year period, with mean age of 35.5+/-7.0 years (range, 22-49). All but two eyes from two patients had myopia of -0.5 D or greater, with mean spherical equivalent power of -5.20+/-5.80 D (range, -24.75+/-0.5). The average IOP at initial diagnosis was 33.7+/-10.5 mm Hg (range, 16-56). Fifteen patients (83.3%) were found to have pigmentary glaucoma at their initial diagnosis. All patients showed homogenous increased TM pigmentation as well as lenticular and/or zonular pigmentation. 61.1% of patients (11 of 18) had Krukenberg spindle. None of the patients exhibited spoke-like midperipheral ITDs except for trace-isolated transillumination in both eyes of the two patients. The most common clinical findings in Chinese PDS patients include homogeneous TM pigmentation and pigment granule dusting on lens zonules and/or posterior peripheral lens surface. ITDs are uncommon in Chinese patients with PDS.

Visualization of Changes of the Iris Configuration After Peripheral Laser Iridotomy in Primary Melanin Dispersion Syndrome Using Optical Coherence Tomography

Pigment or melanin dispersion syndrome is characterized by radial iris transillumination defects, retrocorneal Krukenberg spindle, and dense trabecular pigmentation. Reverse pupillary block has been presumed as one possible pathogenetic mechanism for backward bowing of the iris leading to iris-zonular rubbing and distribution of melanin granules in the anterior chamber. Laser iridotomy is recommended as a treatment to prevent further melanin dispersion and development of pigmentary glaucoma. The effect of Nd:YAG laser iridotomy as a prophylactic and potentially causal treatment in melanin dispersion syndrome can be easily visualized by optical coherence tomography as a fast and noncontact procedure.

Clinical signs and characteristics of pigmentary glaucoma in Chinese

To report the clinical findings in 21 Chinese patients with pigmentary glaucoma (PG). Medical charts of 21 patients diagnosed with PG between 1993 and 2006 at the Beijing Tongren Eye Center were reviewed. From our database, 14 men and seven women were identified as having PG. The mean age of the subjects at the time of the diagnosis was 35.3+/-6.8 years. All but one patient had myopia >-0.5 diopters (D) with a mean spherical equivalent refractive error of -5.38+/-2.56 D. The average intraocular pressure at the initial diagnosis was 34.5+/-10.3 mmHg. All 17 patients with visibility chart documentation of the appearance of the peripheral lens and zonule showed lenticular and/or zonular pigmentation. The irides of all 15 subjects for whom detailed descriptions of the iris configuration were reported were bowed posteriorly. None of the subjects had iris transillumination defects (TIDs) except for trace areas of transillumination in both eyes of one patient. In these Chinese patients with PG, homogeneous increased trabecular pigmentation, dusting of the peripheral lens or zonule with pigment granules, and posterior bowing of the iris were common. Typical spoke-like radial TIDs were not observed.

Annular and central heavy pigment deposition on the posterior lens capsule in the Pigment dispersion syndrome

To report annular and central heavy pigment deposition on the posterior lens capsule in a case of pigment dispersion syndrome. Case report. A 36-year-old female with bilateral pigment dispersion syndrome presented with progressive decrease in visual acuity in the right eye over the past 1-2 years. Clinical examination revealed the typical findings of pigment dispersion syndrome including bilateral Krunkenberg spindles, iris transillumination defects, and dense trabecular meshwork pigmentation. Remarkably, annular and central dense pigmentation of the posterior lens capsule was noted in the right eye. Annular pigment deposition on the posterior lens capsule may be a rare finding associated with pigment dispersion syndrome. Such a finding suggests that there may be aqueous flow into the retrolental space in some patients with this condition. The way of central pigmentation is the entrance of aqueous to Berger's space. In our case, it is probable that spontaneous detachment of the anterior hyaloid membrane aided this entrance.

Analysis of Ocular Hypopigmentation inRab38cht/chtMice

To characterize the ocular phenotype resulting from mutation of Rab38, a candidate gene for Hermansky-Pudlak syndrome. Chocolate mice (cht, Rab38(cht/cht)) and control heterozygous (Rab38(cht/)(+)) and wild-type mice were examined clinically, histologically, ultrastructurally, and electrophysiologically. Mice homozygous for both the Rab38(cht) and the Tyrp1(b) alleles were similarly examined. Rab38(cht/cht) mice showed variable peripheral iris transillumination defects at 2 months of age. Patches of RPE hypopigmentation were noted clinically in 57% of Rab38(cht/cht) eyes and 6% of Rab38(cht/)(+) eyes. Rab38(cht/cht) mice exhibited thinning of the iris and RPE and larger b-wave amplitudes in the scotopic range when compared with the control animals. Compared with wild-type mice, Rab38(cht/cht) melanosomes were smaller and there were fewer in neuroectodermally derived retinal pigment epithelium; in neural crest-derived choroid melanocytes, they were smaller in size only. Mutation of both Rab38 and Tyrp1 produced mice with ocular and coat color pigment dilution greater than that seen with either mutation alone. Comprehensive clinical and pathologic analyses showed no other organ system or blood defects in Rab38(cht/cht) mice. Rab38(cht/cht) mice show ocular characteristics reminiscent of human oculocutaneous albinism, as well as iris and RPE thinning. The synergistic effects of the Rab38(cht) and Tyrp1(b) alleles suggest that TYRP1 is not the only target of RAB38 trafficking. This mouse line provides a useful model for studying melanosome biology and its role in human ocular diseases.

Infrared Imaging Technique may Help Demonstrate Iris Transillumination Defects in Blacks who Show Other Pigment Dispersion Syndrome Clinical Signs

Pigment dispersion syndrome (PDS) is considered to be rare among blacks, although the inability to detect iris transillumination defects (ITDs) among very darkly pigmented irides could diminish the clinician's commitment toward the PDS diagnosis due to uncertainty brought on by the lack of this clinical sign. The goal of this study was to investigate the potential utility of a new infrared (IR) imaging technique to demonstrate ITDs among a group of blacks whose initial PDS diagnosis had to be based on pigment dispersal signs other than iris transillumination. A previously described digital camera system, modified to detect visible and IR light, was used to image the irides of 10 blacks (20 eyes, 8 females, 2 males; age range=51 to 67 y) considered to have PDS on the basis of the clinical signs not including the presence of ITDs as detected with traditional slit lamp examination. Only 1 eye of 2 different subjects had ITDs that were detected with slit lamp examination, but these consisted of a very small, isolated ITD of questionable importance in each of the eyes. Normal control eyes that were matched according to age, race, sex, and refractive error were also photographed, and 2 glaucoma specialists independently reviewed PDS/control eye pairs in a masked fashion. They were instructed to select the eye more likely to be the PDS eye without the benefit of clinical information other than the digital transillumination characteristics. Observer no. 1 correctly selected the PDS eye among 19 of 20 (95%) PDS-normal eye pairs, and observer no. 2 correctly selected the PDS eye among 15 of 20 (75%) matched pairs. On the basis of these results, it was unlikely that observer no. 1 (Fisher exact test, P<0.0001) or observer no. 2 (P=0.06) selected the PDS eye IR image due to chance alone. It was also unlikely that selection agreement between the 2 observers was due to chance alone (kappa coefficient=0.58). Digital IR iris photography may help demonstrate abnormal ITDs among the darkly pigmented irides of blacks who have signs of pigment dispersal but who do not have detectable ITDs with traditional slit lamp examination. Infrared iris examination with newer methods should be studied further relative to blacks and others because useful clinical and/or research oriented information could be gained.

Sweep Visual Evoked Potential Testing as a Predictor of Recognition Acuity in Albinism

To determine if sweep visual evoked potential (VEP) acuity is predictive of recognition acuity in children with albinism. A retrospective review was performed in children with albinism who underwent sweep VEP testing from 1992 to 2003. All patients had a complete ophthalmologic examination with either binocular or monocular sweep VEP testing and at least 5 years of follow-up. Positive predictability of sweep VEP acuity was defined as final recognition acuity within 1 Snellen line of initial sweep VEP acuity. Of the 13 patients included in the study, 11 had nystagmus, iris transillumination defects, and foveal hypoplasia at initial examination. The mean age at initial sweep VEP testing was 3.1 years (range, 0.1-10.0 years). Five of 13 patients had initial sweep VEP acuity that was predictive of final recognition acuity. Five additional patients had final recognition acuity, which surpassed initial sweep VEP acuity by 2 to 3 lines. Of these 10 patients, the mean duration for recognition acuity to reach VEP acuity was 5.4 years. There was no correlation between predictive VEP acuity and foveal pigmentation, refractive error, strabismus, nystagmus, or longer follow-up. Sweep VEP testing can be used as a predictive tool for recognition acuity in children with albinism. Predictability was found in a clinical spectrum of albinism.

Recurrent vitreous hemorrhage secondary to haptic-induced chafing

Case report: After cataract extraction and placement of a posterior chamber intraocular lens, a 70-year-old man had 5 vitreous hemorrhages over 3 years. Iris transillumination defects and apposition of the nasal haptic and ciliary body were found.Comments: Iris chafing is a rare complication of cataract extraction. Vitreous hemorrhage presumably resulted from iris erosion caused by the IOL haptic.

Injektorimplantation sklerafixierter Faltlinsen

In this pilot study, a new injector technique for small-incision implantation of scleral-fixated intraocular lenses (IOLs) was evaluated for IOL stability and visual rehabilitation. Secondary lens implantation was performed in 18 aphakic eyes using a new small incision technique with injector implantation. This allowed for haptic suturing with the lens body inside the cartridge. All patients were followed-up for best-corrected visual acuity, refraction, IOL evaluation and ultrasound biomicroscopy. In all eyes the IOL was stable without tilt or torque. Best-corrected visual acuity improved 2.2 ETDRS lines after 1 week and 3.1 lines after a mean follow-up time of 7.9+/-2.8 months. Two eyes were complicated with small, peripheral transillumination defects (n=2), but no pigmentary glaucoma occurred. By using a self-sealing tunnel incision and injector technique, significant fluid egress and consecutive transient hypotony is minimized throughout the whole procedure. The technique shows a high IOL stability without tilt and assures rapid visual rehabilitation.

Review of Patients with Basal Cell Nevus Syndrome

To review patients with basal cell nevus syndrome (BCNS), documenting presentation, referrals, treatment patterns, and associated morbidity. Cross-sectional review and retrospective data collection of 39 patients with BCNS. Patients from the BCNS support group were invited to be examined. Demographics, presenting features, associated pathologies, and treatment modalities were recorded. Demographic data, age at presentation, age at diagnosis, spectrum of ophthalmic and periocular disease, treatment modalities used, and periocular deformities developed were reviewed. Thirty-nine patients were included with age range of 5 to 72 years. Presenting clinical features included odontogenic keratocyst in 17 patients and basal cell carcinoma in 13 patients; less common presentations were with congenital malformations (n = 2), with ophthalmic associations (n = 3), and at genetic counseling (n = 4). Seventeen of the 39 patients confirmed a parental diagnosis of BCNS. Basal cell carcinoma developed in 18 of the 28 patients before the age of 30, confirming the reported early age of onset. Periocular basal cell carcinoma was reported in 24 of 39 patients (61%), with recurrent disease reported in 17 of these 24 (71%), despite a variety of treatment modalities used. Associated ophthalmic features were multiple eyelid cysts (15 patients), strabismus (9 patients), myopia (5 patients), hyperopia (7 patients), cataracts (5 patients), myelinated nerve fibers (3 patients), amblyopia (3 patients), and nystagmus and iris transillumination defects (2 patients each). All patients were involved in multidisciplinary medical care. Patients with BCNS frequently have ophthalmic manifestations, particularly periocular basal cell carcinoma. Multidisciplinary care is essential in the care of the patient with BCNS. Early diagnosis of BCNS may allow for skin protection and surveillance at an earlier age.

Bilateral acute depigmentation of the iris

To report on five cases of unusual bilateral stromal depigmentation of the iris and pigment dispersion masquerading as uveitis. We describe the clinical features of five consecutive patients who presented with acute depigmentation of the iris stroma between June and October 2003. Four patients were female, one was male. Age at presentation ranged from 15 to 25 years. Presenting symptoms were sudden-onset ocular discomfort and red eye in four patients and change of eye color in one patient. All patients had bilateral involvement, with a symmetrical diffuse depigmentation of the iris stroma in three cases and patchy areas of iris depigmentation in two. Other common features were mild ciliary injection (seven eyes), Krukenberg spindle (seven eyes), circulating pigment in the anterior chamber (eight eyes), and heavy pigment deposition in the angle (ten eyes). No eyes had iris transillumination defects, inflammatory keratic precipitates or inflammatory cells in the anterior chamber. Systemic laboratory work-up was unrewarding in all cases, and PCR analysis of the aqueous humor for HSV1 and 2 was negative in one patient. Four patients were treated with a short course of topical corticosteroids and three with oral acyclovir. One patient was lost to follow-up. The remaining four patients were followed up for 6-19 months with a stable clinical picture. In contrast to pigment dispersion syndrome, pigment seemed to be released from iris stroma in the five cases described here. Although patchy depigmentation of the iris resembled the lesions seen in herpetic iridocyclitis in two of the patients, symmetrical bilateral involvement and lack of intraocular inflammation were the differentiating features. The patients described here could represent a new entity or an unusual presentation of herpetic eye disease.

Clinical outcomes of phakic refractive lens in myopic and hyperopic eyes: 1-year results

To confirm the safety, efficacy, and predictability of the surgical correction of myopia and hyperopia with the phakic refractive lens (PRL) (Medennium Inc.). St. Eriks Eye Hospital, Stockholm, Sweden. This was a prospective clinical study of 20 eyes, 14 myopic and 6 hyperopic, that had PRL implantation at St. Eriks Eye Hospital from April to November 2002. Examinations were performed preoperatively and 1 day, 1 week, 3 months, and 1 year postoperatively. Follow-up included evaluation of the PRL rotation with retroillumination photography, evaluation of the distance between the PRL and the crystalline lens with Scheimpflug image, laser flare, endothelial cell count, uncorrected (UCVA) and best corrected (BCVA) visual acuity, residual refractive error, refractive stability, intraocular pressure, and induced cataract. Postoperatively, 11 eyes (55%) gained 1 or more lines, 5 eyes (25%) had no change, and 4 eyes (20%) lost 1 line of BCVA. No eye lost 2 or more lines. Mean UCVA was 0.87+/- 0.29 postoperatively. Laser flare values were highest 1 day after operation with normalization at 3 months and without changes at 1 year (P<.05). A rotation of 10 degrees or more was found in 15 eyes (75%) during the first year. The distance between the PRL and crystalline lens was considerably less at 1 year than at baseline (P<.05). There was no statistically significant endothelial cell loss induced by the PRL (P<.05). No induced cataract, glaucoma, or inflammation was observed. In 1 hyperopic eye, horizontal iris transillumination defects were noticed at 1 year. Safety and efficacy indexes were high at 1-year follow-up. The PRL rotated slightly in the posterior chamber. The distance between the PRL and the crystalline lens was considerably less at 1 year than at baseline.

Anterior megalophthalmos with pigmentary glaucoma

To describe the ocular findings and clinical characteristics of two sisters having anterior megalophthalmos with megalocornea and pigmentary glaucoma. A complete ophthalmological examination was performed. Megalocornea and transillumination defects of the irides were observed associated with deep anterior chambers in both cases. In these cases, a diagnosis of anterior megalophthalmos with pigmentary glaucoma was made. Anterior megalophthalmos is a rare hereditary condition. The ophthalmologist should be made aware of the many ocular findings that may be associated with megalophthalmos.

Trypan blue staining of anteriorly placed zonules in patients with pigment dispersion

The article by Kelty and coauthors1 highlights the seldom-considered finding of anteriorly placed zonules. The authors noted staining of the zonules after application of indocyanine green (ICG) dye used to enhance visualization of the anterior capsule. This is of particular relevance in patients having phacoemulsification surgery because of the need for an intact continuous curvilinear caspsulorhexis to enable stable in-the-bag fixation of the intraocular lens.2 We have observed anteriorly placed zonules made visible following the use of trypan blue dye 0.1% (Vision Blue, Dorc International) to stain the anterior capsule during cataract surgery in 2 patients with signs of pigment dispersion. Moroi et al.3 recently described a series of 15 patients with anteriorly placed zonules associated with signs of anterior segment pigment dispersion. They speculate that contact between the zonules and iris pigment epithelium at the pupillary ruff and central iris was the cause of pigment release. Although often subtle, long, anteriorly inserted zonules may be visible on slitlamp biomicroscopy and are easily missed. We suspect these zonules may be more common than thought. Anteriorly inserted zonules should be specifically looked for during preoperative assessment of patients with cataract, particularly patients with signs of pigment dispersion in the form of corneal endothelial pigment deposits, iris transillumination defects, and increasedtrabecular meshwork pigmentation. When anteriorly inserted zonules are noted, consideration should be given to improving preoperative visualization of the zonules with the use of trypan blue or ICG staining. The creation of a small capsulorhexis to minimize tearing of the zonular insertions and placement of a capsular tension ring may reduce the potential for peripheral extension of the capsulorhexis and zonular dialysis. Simon D.M. Chen FRCOphth Nicholas Glover FRCOphth C. K. Patel FRCOphth Oxford, United Kingdom

Atypical pigment dispersion syndrome in a child*1

Purpose To describe the features of atypical pigment dispersion in a child. Design Observational case report. Methods Retrospective chart review. Results An 8-year-old boy presented with midperipheral iris transillumination defects, iris backbowing, heavy pigmentation of the trabecular meshwork, and elevated intraocular pressure. He also had several atypical features including emmetropia, mild posterior subcapsular cataract, small pupils, and peripheral anterior synechiae. Conclusion Pigment dispersion in childhood is unusual and may have different features from those classically described in adults.

Atypical pigment dispersion syndrome in a child

Purpose To describe the features of atypical pigment dispersion in a child. Design Observational case report. Methods Retrospective chart review. Results An 8-year-old boy presented with midperipheral iris transillumination defects, iris backbowing, heavy pigmentation of the trabecular meshwork, and elevated intraocular pressure. He also had several atypical features including emmetropia, mild posterior subcapsular cataract, small pupils, and peripheral anterior synechiae. Conclusion Pigment dispersion in childhood is unusual and may have different features from those classically described in adults.

What is the risk of developing pigmentary glaucoma from pigment dispersion syndrome?

Purpose To determine the probability of converting from pigment dispersion syndrome to pigmentary glaucoma. Design Retrospective community-based study of all newly diagnosed cases of pigment dispersion syndrome or pigmentary glaucoma. Methods Subjects were patients newly diagnosed with pigment dispersion syndrome or pigmentary glaucoma from 1976 to 1999 in Olmsted County, Minnesota. Criteria for pigment dispersion syndrome were two of three signs: midperipheral, radial iris transillumination defects; Krukenberg spindle; heavy trabecular meshwork pigmentation. Criteria for pigmentary glaucoma were pigment dispersion syndrome and two of three findings: intraocular pressure (IOP) greater than 21 mm, optic nerve damage, or visual field loss. Kaplan-Meier survival curves were used to determine the probability of conversion to pigmentary glaucoma. Results A total of 113 patients were newly diagnosed with pigment dispersion syndrome over the 24-year period. Of these, 9 persons developed pigmentary glaucoma or elevated IOP requiring therapy. The probability of converting to pigmentary glaucoma was 10% at 5 years and 15% at 15 years. An additional 23 patients were found to have pigmentary glaucoma at their initial examination. The mean age at diagnosis of pigmentary glaucoma was 42 ± 12 years; 78% of patients were male, whereas 58% of patients with pigmentary dispersion syndrome glaucoma were male. The most significant risk factor for conversion to pigmentary glaucoma was an IOP greater than 21 mm Hg at initial examination, whereas age, refractive error, and family history of glaucoma were not correlated with conversion. Conclusion The risk of developing pigmentary glaucoma from pigment dispersion syndrome was 10% at 5 years and 15% at 15 years. Young, myopic men were most likely to have pigmentary glaucoma. An IOP greater than 21 mm Hg at initial examination was associated with an increased risk of conversion.

Iris transillumination defects in patients with primary open angle glaucoma.

To examine the incidence and pattern of iris transillumination defects in patients with primary open angle glaucoma (POAG) with and without vascular dysregulation, in comparison to controls. We prospectively examined 24 patients with POAG (M/F 10:14; mean age 59 +/- 14, range 21-76 years) and 23 controls (M/F 10:13; mean age 52 +/- 15, range 25-86 years). Vascular dysregulation was presumed if patients had a typical medical history of vasospasm and a pathological result in nailfold capillaroscopy. Iris transillumination defects were visualized by video-taped, digitized diaphanoscopy and assessed by two blinded observers. We found significantly more iris transillumination defects in POAG than in controls (54.2% vs. 8.7%; chi2 = 8.85; df = 1; p = 0.002). The defects in POAG showed a characteristic radially-streaked pattern different from those described, for instance, in pigment dispersion syndrome, pseudoexfoliation syndrome, and acute glaucoma. Glaucoma patients with vascular dysregulation had a tendency to a higher incidence of transillumination defects than non-vasospastic patients, though this finding was not significant. Patients with POAG have a higher incidence of iris transillumination defects than controls. The underlying mechanisms are not yet clear and call for further investigation.

Nd-YAG laser iridotomy in pigment dispersion syndrome and pigment dispersion glaucoma

Pigment dispersion syndrome is characterized by iris transillumination defects, Krukenberg spindels, and dense trabecular pigmentation. Additional features are bilaterality, myopia, concavity of the peripheral iris, a higher incidence in men than in woman,and young age of onset. A mechanism of reverse pupillary block causes iridozonular friction. Laser iridotomy is recommended as treatment to prevent further pigment dispersion and pigmentary glaucoma.

Digital camera system to perform infrared photography of iris transillumination.

The authors modified a standard digital camera by replacing an internal infrared-blocking filter that allowed photography of iris transillumination defects. Visible and infrared light was produced with a halogen fiberoptic light source that was placed against the inferior eyelid and directed perpendicular to the globe. To obtain images, the camera was mounted to a tabletop tripod placed 3 to 5 in from a chin/headrest apparatus. Images were downloaded onto a personal computer via software and accessories provided by the camera manufacturer. This technique, which is convenient and produces high quality, color images, can highlight details of the normal and pathologic iris. It may have significant utility in clinical research as well as routine clinical care.