Qualitative and quantitative evaluation of acute angle-closure mechanisms.

BACKGROUND: To evaluate ocular biometric parameters in different subtypes of acute angle closure and compared to fellow eyes of AAC and PACS eyes. METHODS: This is a retrospective chart review study. A total of 167 eyes (96 patients) consisting of 71 AAC eyes, 71 fellow eyes of AAC, and 25 PACS eyes were recruited. All patients underwent ocular examination and biometry. The mechanism of AAC was confirmed by ultrasound biomicroscopy. We then subdivided AAC eyes into four subgroups: crowded-angle (CR), lens subluxation (LS) pupillary block (PB), and plateau iris syndrome (PL). Outcome variables included anterior chamber depth (ACD), lens thickness (LT), vitreal length (VL), axial length (AL), lens position and relative lens position (LP and RLP, respectively), and lens axial length factor (LAF). RESULTS: Among the three groups, ACD was shallower in AAC eyes than fellow eyes of AAC and PACS eyes (p < 0.01 for both) and AAC eyes demonstrated a lesser LP and RLP. The LT, VL, AL, and LAF were not significantly different among the three groups. Among the four subgroups, LS displayed the most shallow ACD (p = 0.01). The lens position in PL was greater than in CR and LS (p < 0.05 and <0.01, respectively). CONCLUSIONS: AAC eyes had a more anterior lens position than fellow eyes and PACS eyes, though lens thickness did not differ among the groups. As such, an anterior lens position may offer more sensitive prognostication regarding future development of AAC compared to lens thickness.

Hidden mechanisms beyond the pupillary block in acute angle closure: ultrasound biomicroscopic study.

BACKGROUND: To evaluate the mechanisms of acute angle closure (AAC) other than the pupillary block using ultrasound biomicroscopy. DESIGN: Retrospective chart review. PARTICIPANTS: All patients who were diagnosed with AAC in Ramathibodi Hospital, Bangkok, Thailand, between June 2011 and February 2015 were enrolled. METHODS: Seventy-two patients who were diagnosed with AAC underwent a detailed ocular examination. The diagnosed mechanism of AAC was confirmed by UBM and ocular biometry. MAIN OUTCOME MEASURES: Primary mechanism responsible for acute angle closure. RESULTS: In 72 patients, the mean age was 62.33 ± 10.4 years, 18 (25%) patients were male and 54 (75%) patients were female. The primary mechanism of AAC was iridolenticular wrapping (crowded-angle (CR) plus anterior lens subluxation (LS)) in 49 eyes (68.1%), pupillary block (PB) in 17 (23.6%) eyes, and plateau iris (PL) in 6 (8.3%) eyes. Thirty (41.7%) out of 72 eyes without previous iridotomy before UBM examination were analyzed. The most common primary mechanism in this group was iridolenticular wrapping (20 eyes, 66.7%). There were seven (23.3%) eyes that had a pupillary block, and only three (10.0%) eyes had plateau iris syndrome as the primary mechanism of AAC. There was a single mechanism in 14 (46.7%) eyes, and there were combined mechanisms in 16 (53.3%) eyes. CONCLUSIONS: The most common mechanism contributing to AAC development in this Thai population was iridolenticular wrapping. From this study, we suggest that iridolenticular wrapping was the most common hidden mechanism beyond pupillary block among Thai patients.

The Clinical Spectrum and a New Theory of Pathogenesis of True Exfoliation Syndrome.

PURPOSE: To describe the clinical spectrum and a new theory of pathogenesis of true exfoliation syndrome. DESIGN: Cross-sectional and prospective, observational case series. PARTICIPANTS: Consecutive patients with characteristic peeling of the anterior lens capsule. METHODS: After maximal mydriasis, slit-lamp biomicroscopy, and photography, imaging of the anterior capsule and zonules was performed. The condition was classified into 4 clinical stages: annular anterior capsule thickening with a distinct splitting margin (stage 1), an inward detached crescentic flap lying on the anterior lens (stage 2), a floating and folding translucent membrane behind the iris (stage 3), and a broad membrane within the pupil (stage 4). Serial photography was performed at each 3-month follow-up visit. Ultrastructural examination of dislocated lenses and excised anterior capsules was performed. MAIN OUTCOME MEASURES: Detached membrane morphologic features, zonular defects, pigment deposition, glaucoma, phacodonesis, and cataract. RESULTS: We enrolled 259 patients (424 eyes). Ages ranged from 52 to 97 years (mean age, 75.2±7.1 years). Eleven patients were associated with trauma (n = 1) or intense heat (n = 10), whereas 248 were idiopathic. Two hundred ten patients were followed up every 3 months, with a mean follow-up of 9.6±6.1 months (range, 3-50 months). The detachment started along the anterior zonular insertions in association with zonular disruption. It progressed centrally to higher stages, manifesting a spectrum of disease. Several stages coexisted in a single eye. At the final visit, including 49 patients who were examined once, there were 70, 87, 85, and 17 patients in stages 1, 2, 3, and 4, respectively. All stages shared common histologic findings consisting of diffuse capsular lamellar separation and anterior zonular disruption. All developed cataract. Pigment deposition on the membrane was present in 178 patients (68.7%). Twenty-six patients (10%) had spontaneous phacodonesis. Eighteen eyes (4.2%) demonstrated secondary delamination. CONCLUSIONS: Capsular lamellar separation and anterior zonular disruption are characteristic findings. Aging, heat exposure, and trauma are risk factors. Initial capsular splits occur along the insertions of disrupted anterior zonules. The peeling progresses centrally in association with iris movement and aqueous flow. A second detachment can occur.

Pseudophakic angle-closure from a Soemmering ring.

BACKGROUND: Report of three patients with pseudophakic angle-closure from a Soemmering ring. Three mechanisms of the Soemmering ring induced pseudophakic angle-closure in three patients were demonstrated by meticulous anterior segment examination and ultrasound biomicroscopic (UBM) analysis. CASE PRESENTATION: In the first case, the Soemmering-capsule-IOL complex caused relative pupillary block similar to a phakic eye and was successfully treated with laser iridotomy alone. In the second case, an enlarged Soemmering ring provided posterior iris support in apposition to the anterior chamber angle. We performed a laser capsulotomy through the iridotomised hole. The last, a protruding Soemmering content causing absolute pupillary block became resolved after laser iridotomy and total Soemmering ring content removal. CONCLUSION: Angle-closure in pseudophakic eyes is uncommon. Several causes have been reported in the literatures including Soemmering ring. This is the first report on three different mechanisms of Soemmering ring related angle-closure in pseudophakic eyes. Ultrasound biomicroscopic analysis plays a crucial role as a diagnostic tool.

Twenty-Four-Hour Intraocular Pressure in Chronic Primary Angle-Closure Disease.

PRCIS: Primary angle closure and primary angle closure glaucoma may exhibit normal intraocular pressure. Twenty-four-hour intraocular pressure fluctuation is highest in primary angle closure glaucoma. The degree of peripheral anterior synechiae was associated with a 24-hour intraocular pressure pattern in primary angle-closure disease without laser iridotomy. PURPOSE: The purpose of this study was to study 24-hour intraocular pressure (IOP) patterns in eyes with chronic primary angle-closure disease and evaluate associations between peripheral anterior synechiae (PAS) and 24-hour IOP pattern. PATIENTS AND METHODS: In this prospective cohort study, 59 eyes of 35 Asian patients with chronic primary angle-closure disease underwent complete ocular examinations at Ramathibodi Hospital, Mahidol University. Twenty-four-hour IOP records were obtained using Goldmann applanation tonometry at 2-hour intervals. Peak, mean, and trough 24-hour IOP values and 24-hour IOP fluctuation (difference between peak and trough values) were compared among groups. None of the participants received any treatment before complete data collection. RESULTS: Even univariable analysis demonstrated a significant difference in peak, mean, and trough IOP and 24-hour IOP fluctuation between the 3 groups; the magnitude of trough IOP was not higher than 21 mmHg in all groups. In multivariable analysis, PAC and PACG eyes showed significantly higher peak IOP ( P =0.020 and 0.006, respectively) and 24-hour IOP fluctuation ( P =0.048 and 0.001, respectively) compared with PACS eyes. In comparison between combined PACS and PAC eyes versus PACG eyes, PACG eyes revealed significantly higher 24-hour IOP fluctuation. The degree of PAS was associated with peak and mean IOP values and with 24-hour IOP fluctuation in PAC and PACG eyes. CONCLUSIONS: Twenty-four-hour IOP fluctuation was highest in PACG eyes. Although PAC and PACG eyes showed higher peak IOP and 24-hour IOP fluctuation values, compared with PACS eyes, trough IOP in PAC and PACG eyes were mostly below 21 mmHg. In addition, the degree of PAS was associated with a 24-hour IOP pattern in either PAC or PACG eyes.

Parapapillary choroidal microvascular density in acute primary angle-closure and primary open-angle glaucoma: an optical coherence tomography angiography study.

BACK GROUND/AIMS: To determine whether parapapillary choroidal microvasculature (PPCMv) density, measured by optical coherence tomography angiography, differed between acute primary angle-closure (APAC), primary open-angle glaucoma (POAG) and controls. METHODS: This is a prospective, cross-sectional, observational study. Data from 149 eyes from two academic referral centres were analysed. Automated PPCMv density was calculated in inner and outer annuli around the optic nerve region in addition to the peripapillary superficial vasculature, using customised software. A generalised estimating equation was used to compare vessel densities among groups, adjusted for confounders. RESULTS: Data from 40 eyes with APAC, 65 eyes with POAG and 44 eyes in healthy controls were gathered and analysed. Global radial peripapillary capillary densities were reduced in eyes with APAC and POAG compared with controls (p=0.027 and 0.136, respectively). Mean outer annular PPCMv density in the POAG group was lower vs the APAC group by 3.6% (95% CI 0.6% to 6.5%) (p=0.018) in the multivariable model adjusted for confounders. The mean difference in inner and outer superior PPCMv between the POAG and APAC groups was 5.9% and 4.4% (95% CI 1.9% to 9.9% and 1.0% to 7.7%, respectively; both p<0.010). Furthermore, POAG and APAC groups both had significantly lower PPCMv compared with controls (both, p<0.001). CONCLUSIONS: While superficial peripapillary vessels were affected to similar degrees in POAG and APAC, PPCMv drop-out was greater with POAG versus APAC, suggesting that choroidal vessel density may be affected to a lesser extent following an acute increase in intraocular pressure before glaucoma develops.

Light and electron microscopic features of preclinical pseudoexfoliation syndrome.

PURPOSE: This study sought to explore the features of the anterior lens capsule in patients with preclinical pseudoexfoliation syndrome (pPEX) via light microscopy (LM) and transmission electron microscopy (TEM). DESIGN: Cross-sectional, prospective, and observational case series. METHODS: We recruited consecutive patients with and without pPEX who underwent routine cataract surgery at Ramathibodi Hospital, between April 2018 and November 2020. pPEX can be characterized by pigmented spoke-wheel deposition (P) on the anterior lens capsule, midperiphery cleft/lacunae (C), faint central disc present within the photopic pupil (D), white-spoke pattern (W) noted at the midperiphery, and a combination of at least two signs (Co). LM and TEM were used to examine anterior lens capsule specimens for the presence of characteristic pseudoexfoliation material (PXM). The features of the anterior lens capsule in pPEX explored via LM and TEM were recorded. RESULTS: This study included a total of 96 patients (101 excised anterior lens capsules); among them, 34 (35 excised anterior lens capsules) exhibited pPEX signs (pPEX group) but 62 (66 excised anterior lens capsules) did not (control group). The patients had a mean age of 74 ± 7 (range, 58-89) years. LM and TEM revealed no definite PXM in any patient. In the pPEX group, LM analysis identified two capsule specimens with suspected PXM; PXM precursors were observed in 1 of the 34 excised capsule specimens analyzed via TEM. Furthermore, 39 eyes (59.09%) exhibited signs of true exfoliation syndrome (TEX) in LM analysis (12.82%, 25.64%, 10.26%, 10.26%, and 41.03% for patients exhibiting P, D, C, W, and Co, respectively). However, no TEX signs were observed in the control group. We found that the anterior lens capsules exhibiting C and D were significantly associated with TEX (odds ratio = 5.4 and 7.9; P = 0.007 and 0.004, respectively). CONCLUSIONS: LM analysis revealed no definite PXMs were detected in the excised anterior lens capsules, whereas TEM analysis showed PXM precursors in one specimen (2.94%). Notably, a significant association was observed between C and D signs and TEX.

Differentiating Glaucomatous Optic Neuropathy From Non-glaucomatous Optic Neuropathies Using Deep Learning Algorithms.

PURPOSE: A deep learning framework to differentiate glaucomatous optic disc changes due to glaucomatous optic neuropathy (GON) from non-glaucomatous optic disc changes due to non-glaucomatous optic neuropathies (NGONs). DESIGN: Cross-sectional study. METHOD: A deep-learning system was trained, validated, and externally tested to classify optic discs as normal, GON, or NGON, using 2183 digital color fundus photographs. A Single-Center data set of 1822 images (660 images of NGON, 676 images of GON, and 486 images of normal optic discs) was used for training and validation, whereas 361 photographs from 4 different data sets were used for external testing. Our algorithm removed the redundant information from the images using an optic disc segmentation (OD-SEG) network, after which we performed transfer learning with various pre-trained networks. Finally, we calculated sensitivity, specificity, F1-score, and precision to show the performance of the discrimination network in the validation and independent external data set. RESULTS: For classification, the algorithm with the best performance for the Single-Center data set was DenseNet121, with a sensitivity of 95.36%, precision of 95.35%, specificity of 92.19%, and F1 score of 95.40%. For the external validation data, the sensitivity and specificity of our network for differentiating GON from NGON were 85.53% and 89.02%, respectively. The glaucoma specialist who diagnosed those cases in masked fashion had a sensitivity of 71.05% and a specificity of 82.21%. CONCLUSIONS: The proposed algorithm for the differentiation of GON from NGON yields results that have a higher sensitivity than those of a glaucoma specialist, and its application for unseen data thus is extremely promising.

Pseudophakic Angle Closure Due to Vitreous Block Following Ureteroscopic Lithotripsy.

BACKGROUND: Here, we describe a patient who exhibited pseudophakic angle closure due to vitreous block following ureteroscopic lithotripsy under general anesthesia. CASE PRESENTATION: A 57-year-old Thai man presented with sudden eye pain and blurring of vision in the left eye following ureteroscopic lithotripsy under general anesthesia. The patient had a history of coconut hit into his left eye which resulted in traumatic anterior lens subluxation, for which he had undergone phacoemulsification and scleral-fixated intraocular lens implantation in the left eye. Prior scleral fixation procedure, anterior vitrectomy was not performed. Clinical examination showed mushroom-shaped vitreous in the anterior chamber with absolute pupillary block, which had resulted in acute angle closure. Thus, topical and oral antiglaucoma medications were administered to achieve normal intraocular pressure in the left eye, followed by laser peripheral iridotomy in that eye. The anterior chamber depth was successfully increased. Limited anterior vitrectomy by a pars plana approach was performed to prevent recurrent angle closure. The patient's vision improved and his intraocular pressure remained controlled without any antiglaucoma medication. CONCLUSION: Vitreous block can occur in patients with pseudophakia, especially in the presence of a ruptured posterior capsule. Cautious intraoperative anterior vitrectomy and surgical iridectomy are warranted. General anesthesia may contribute to the onset of vitreous block in susceptible patients.

Peripapillary Perfused Capillary Density in Acute Angle-Closure Glaucoma: An Optical Coherence Tomography Angiography Study.

PURPOSE: To compare peripapillary perfused capillary density (PCD) on optical coherence tomography angiography among resolved acute angle-closure (AAC), primary open-angle glaucoma (POAG), and control eyes. DESIGN: Prospective, cross-sectional, observational study. METHODS: All patients with resolved AAC or POAG of varying severity and controls were enrolled. We obtained 4.5 × 4.5 mm2 optical coherence tomography angiography images of the optic nerve head. PCD was analyzed using customized software with major vessel removal. Continuous variables were assessed using the analysis of variance and Bonferroni correction test. A marginal model of generalized estimating equations was used to adjust for confounding factors and interocular correlation. RESULTS: The study included 44 eyes with resolved AAC (mean duration of elevated intraocular pressure, 8.1 ±â€Š10.9 days), 69 eyes with POAG, and 49 control eyes. PCD showed a similar decrease between AAC and POAG eyes (P > 0.99). After adjusting for age and sex, the mean difference in global PCD between each of the POAG stage groups and the AAC group was the highest in the severe POAG group (-3.43; 95% confidence interval [CI], -11.38 to 2.52; P = 0.211), followed by the mild POAG (0.68; 95% CI, -3.26 to 4.62; P = 0.735) and moderate POAG (0.20; 95% CI, -5.21 to 5.61; P = 0.942) groups. The duration of increased intraocular pressure did not affect PCD (P = 0.258 and 0.168 for global and annular PCDs, respectively). CONCLUSIONS: The degree of microvascular attenuation in AAC eyes was not different from that in POAG eyes.

Comparison of Two Tube-Modification Techniques in Baerveldt Glaucoma Implantation in Refractory Glaucoma.

IMPORTANCE: To compare treatment outcomes among a stent group, ligature group and combined group in eyes with refractory glaucoma. BACKGROUND: Various techniques have been used intra-operatively to restrict the aqueous flow in Baerveldt glaucoma implantation. DESIGN: Retrospective chart review. PARTICIPANTS: All glaucoma patients aged over 18-years old who had Baerveldt implantation in Ramathibodi Hospital, Bangkok, Thailand, between October 2011 and February 2018 were included for analysis. METHODS: Retrospective interventional research was conducted. All glaucoma patients who underwent drainage device implantations were retrospectively reviewed from medical records and divided into three groups: stent group, ligature group, and combined group. The primary outcome was post-operative intraocular pressure (IOP) changes and BCVA (logMAR) change. The secondary outcome is treatment failure. Repeated measurements with mixed models and multi-level parametric survival model stratified by propensity score and eye side were used to compare the primary and secondary outcomes between stent group and ligature group. MAIN OUTCOME MEASURES: Treatment failure between two groups. RESULTS: A total of 163 patients with a mean age of 57.11 ± 19.04 years, implanted with Baerveldt tube, were eligible. There were no significant differences between stent and ligature groups in terms of post-operative IOP changes [mean difference with 95% confidence interval = 0.53 (-0.49, +1.55) vs -0.02 (-0.84, +0.81); P = 0.411] and post-operative BCVA (logMAR) change (0.02 (-0.13, +0.18) vs -0.05 (-0.18, +0.07); P = 0.465). The hazard ratio and 95% confidence interval of treatment failure in ligature group were 2.57 (0.72-9.19) compared with the stent group. CONCLUSION: This study suggests a trend toward a better result in the stent group compared with the ligature group. Further research with a larger sample size and randomized control trial is warranted.

Effect of Visibility of the Ciliary Body Processes on Ocular Biometric Parameters in Patients with Primary Angle Closure.

PURPOSE: To evaluate the differences in ocular biometric parameters between eyes with primary angle closure (PAC) with and without visible ciliary body processes (CBP) (PAC+CBP and PAC-CBP) and normal open-angle controls. STUDY DESIGN: Cross-sectional study. METHODS: Eyes with PAC and normal open-angle controls underwent detailed ocular examinations and gonioscopy to determine the visibility of the CBP. The following ocular biometric parameters were determined using A-scan ultrasound biometry: axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and vitreous length (VL). The lens-axial length factor (LAF) and relative lens position (RLP) were also calculated. Continuous variables were assessed by analysis of variance with Bonferroni correction. Multiple linear regression analysis was performed to adjust for confounding factors. Area under the receiver operating characteristic curves were calculated to determine the diagnostic capability of biometric parameters. RESULTS: 84 PAC+CBP eyes, 57 PAC-CBP eyes, and 32 normal open angle control eyes were evaluated. The means of the ocular biometric values were significantly different among the three groups. AL, ACD, LT, VL, LAF, and RLP were also significantly different among the three groups in the multivariate regression analysis. AL, ACD, and VL were lower in the PAC+CBP group and LT, RLP, and LAF were greater in the PAC+CBP group than in the PAC-CBP and control groups. LAF ≥ 2.4 is the cutting point with the highest sensitivity and specificity to differentiate PAC+CBP from PAC-CBP. CONCLUSIONS: The ocular biometric parameters in the PAC+CBP group were more strongly associated with a crowded anterior segment than in the other groups. Visibility of CBP in PAC-affected eyes may serve as a surrogate for an anterior segment crowding mechanism and help to select the most appropriate treatment in individual cases.

Eight-ball hyphema after laser iridotomy in a patient with undiagnosed hypocellular myelodysplastic syndrome.

INTRODUCTION: We report a rare case of unexpected gross hyphema in the right eye (OD) and eight-ball hyphema in the left eye (OS) from a bilateral laser iridotomy in an acute primary angle-closure patient. We also demonstrated the effectiveness of the inferior full-thickness trabeculectomy with daily intracameral air injection as an alternative treatment in eight-ball hyphema. CASE REPORT: An 81-year-old Thai female presented with gross hyphema grade II OD and eight-ball hyphema with blood-stained cornea OS after laser iridotomy. The patient was scheduled for surgery and the preoperative blood test showed bicytopenia. We performed anterior chamber washout OD and an inferior full-thickness trabeculectomy with daily intracameral air injection OS. The hyphema completely resolved on the following day OD and 3 days after surgery OS. The inferior bleb OS did not raise with digital pressure and became nonfunctional in 7 days. No recurrent hyphema was found in both eyes (OU) during 6 months of follow-up. This patient was ultimately diagnosed with hypocellular myelodysplastic syndrome (MDS). CONCLUSION: Gross hyphema after laser iridotomy can be seen in patients with hypocellular MDS. The inferior full-thickness trabeculectomy is an alternative surgical procedure for an eight-ball hyphema.

Brown-McLean syndrome: the role of iridodonesis.

PURPOSE: The aim of this study was to report a case series of Brown-McLean syndrome (BMS). METHODS: The charts of 28 patients with BMS at Ramathibodi and Rutnin Hospital from 1981 to 2015 were reviewed. RESULTS: BMS is a rare condition with corneal edema involving the peripheral cornea with orange-brown pigment deposition underlying the edematous area. The edema typically starts inferiorly and advances circumferentially to superior cornea. Central cornea remains clear in most patients. We report 28 patients with BMS that occurred either spontaneously or after various intraocular procedures. Ultrasound biomicroscopy was performed to demonstrate the iridocorneal relationship. CONCLUSION: Iridocorneal relationship from the ultrasound biomicroscopy study in four patients did not support previous hypothesis about the role of iridodonesis impact on corneal endothelium. Patients with BMS can rarely progress to corneal decompensation; however, they should be periodically monitored and made aware of early clinical signs of their complications.

Assessment of a rapid method to determine approximate visual acuity in large surveys and other such settings.

PURPOSE: To evaluate the efficacy of an iPod application developed to rapidly measure approximate visual acuity (VA). DESIGN: Prospective, cross-sectional study. METHODS: One hundred four subjects (104 eyes) with a wide range of VA underwent both Early Treatment Diabetic Retinopathy Study (ETDRS) VA testing and iPod application testing. The application presented 4 randomized ETDRS letters at the Snellen equivalent of 20/40 and 20/200 each. In separate analyses, sensitivity and specificity of the iPod test were determined using the ETDRS VA testing results as the gold standard and defining "failure" to see as identifying 1, 2, 3, or all 4 letters incorrectly out of 4 trials. The minimum number of iPod trials necessary to maintain high accuracy was determined by defining a "failure" as getting the first, first 2, first 3, or all trial letters incorrect. In 13 subjects, the time necessary to perform the testing was determined. RESULTS: Forty-six subjects had an ETDRS Snellen equivalent VA ≥20/40; 45 had a VA <20/40 and ≥20/200; and 13 had a VA <20/200. The mean ± SD testing time for the 3 groups was 43 ± 13, 60 ± 15, and 72 ± 25 seconds, respectively. The highest sensitivity and specificity combination was observed when a "failure" was defined as getting all letters incorrect for both the 20/40 (sensitivity = 98.3%/specificity = 93.5%) and 20/200 (sensitivity/specificity both 92.3%) cutoffs. CONCLUSIONS: An iPod application requiring about a 1-minute testing time provides an objective, portable, rapid, and low-cost method to determine approximate VA, allowing VA testing to be performed efficiently in large surveys and other settings where approximate VA should be measured.

Development and validation of an associative model for the detection of glaucoma using pupillography.

PURPOSE: To develop and validate an associative model using pupillography that best discriminates those with and without glaucoma. DESIGN: A prospective case-control study. METHODS: We enrolled 148 patients with glaucoma (mean age 67 ± 11) and 71 controls (mean age 60 ± 10) in a clinical setting. This prototype pupillometer is designed to record and analyze pupillary responses at multiple, controlled stimulus intensities while using varied stimulus patterns and colors. We evaluated three approaches: (1) comparing the responses between the two eyes; (2) comparing responses to stimuli between the superonasal and inferonasal fields within each eye; and (3) calculating the absolute pupil response of each individual eye. Associative models were developed using stepwise regression or forward selection with Akaike information criterion and validated by fivefold cross-validation. We assessed the associative model using sensitivity, specificity and the area-under-the-receiver operating characteristic curve. RESULTS: Persons with glaucoma had more asymmetric pupil responses in the two eyes (P < 0.001); between superonasal and inferonasal visual field within the same eye (P = 0.014); and smaller amplitudes, slower velocities and longer latencies of pupil responses compared to controls (all P < 0.001). A model including age and these three components resulted in an area-under-the-receiver operating characteristic curve of 0.87 (95% CI 0.83 to 0.92) with 80% sensitivity and specificity in detecting glaucoma. This result remained robust after cross-validation. CONCLUSIONS: Using pupillography, we were able to discriminate among persons with glaucoma and those with normal eye examinations. With refinement, pupil testing may provide a simple approach for glaucoma screening.

Symmetry of the pupillary light reflex and its relationship to retinal nerve fiber layer thickness and visual field defect.

PURPOSE: To assess the relationship between the pupillary light reflex (PLR) and visual field (VF) mean deviation (MD) and retinal nerve fiber layer (RNFL) thickness. METHODS: A total of 148 patients with glaucoma (mean age 67 ± 11, 49% female) and 71 controls (mean age 60 ± 10, 69% female) were included in this study. Using a pupillometer, we recorded and analyzed pupillary responses at varied stimulus patterns (full field, superonasal and inferonasal quadrant arcs). We compared the responses between the two eyes, compared responses to stimuli in the superonasal and inferonasal fields within each eye, and calculated the absolute PLR value of each individual eye. We assessed the relationship among PLR, MD, and RNFL thickness using the Pearson correlation coefficient. For analyses performed at the level of individual eyes, we used multilevel modeling to account for between-eye correlations within individuals. RESULTS: For every 0.3 log unit difference in between-eye asymmetry of PLR, there was an average 2.6-dB difference in visual field MD (correlation coefficient R = 0.83, P < 0.001) and a 3.2-µm difference in RNFL thickness between the two eyes (R = 0.67, P < 0.001). Greater VF damage and thinner RNFL for each individual eye were associated with smaller response amplitude, slower velocity, and longer time to peak constriction and dilation after adjusting for age and sex (all P < 0.001). However, within-eye asymmetry of PLR between superonasal and inferonasal stimulation was not associated with corresponding within-eye differences in VF or RNFL. CONCLUSIONS: As measured by this particular device, the PLR is strongly correlated with VF functional testing and measurements of RNFL thickness.