Strong coupling-induced frequency shifts of highly detuned photonic modes in multimode cavities.

Strong coupling between light and molecules is a fascinating topic exploring the implications of the hybridization of photonic and molecular states. For example, many recent experiments have explored the possibility that strong coupling of photonic and vibrational modes might modify chemical reaction rates. In these experiments, reactants are introduced into a planar cavity, and the vibrational mode of a chemical bond strongly couples to one of the many photonic modes supported by the cavity. Some experiments quantify reaction rates by tracking the spectral shift of higher-order cavity modes that are highly detuned from the vibrational mode of the reactant. Here, we show that the spectral position of these cavity modes, even though they are highly detuned, can still be influenced by strong coupling. We highlight the need to consider this strong coupling-induced frequency shift of cavity modes if one is to avoid underestimating cavity-induced reaction rate changes. We anticipate that our work will assist in the re-analysis of several high-profile results and has implications for the design of future strong coupling experiments.

Selection Bias in Strong Coupling Experiments.

The strong coupling of light and molecules offers a potential new pathway to modify the properties of photonic modes and molecules. There are many reasons to be optimistic about the prospects of strong coupling; however, progress in this field is currently hindered by challenges in reproducibility, problems associated with differentiating between strong coupling and other effects, and the lack of a clear theoretical model to describe the reported effects. Concerning the question of differentiating between strong coupling and other possible mechanisms when examining experimental data, here, we show how cognitive bias can lead us to place undue emphasis on a given interpretation of unsystematic experimental data. We hope that this Viewpoint will, where appropriate, help readers to plan strong coupling experiments more carefully and evaluate the significance of the data obtained from them.

Non-Polaritonic Effects in Cavity-Modified Photochemistry.

Strong coupling of molecules to vacuum fields is widely reported to lead to modified chemical properties such as reaction rates. However, some recent attempts to reproduce infrared strong coupling results have not been successful, suggesting that factors other than strong coupling may sometimes be involved. In the first vacuum-modified chemistry experiment, changes to a molecular photoisomerization process in the ultraviolet-visible spectral range are attributed to strong coupling of the molecules to visible light. Here, this process is re-examined, finding significant variations in photoisomerization rates consistent with the original work. However, there is no evidence that these changes need to be attributed to strong coupling. Instead, it is suggested that the photoisomerization rates involved are most strongly influenced by the absorption of ultraviolet radiation in the cavity. These results indicate that care must be taken to rule out non-polaritonic effects before invoking strong coupling to explain any changes of properties arising in cavity-based experiments.

Origin of an Anticrossing between a Leaky Photonic Mode and an Epsilon-Near-Zero Point of Silver.

Strong light-matter coupling hybridizes light and matter to form states known as polaritons, which give rise to a characteristic anticrossing signature in dispersion plots. Here, we identify conditions under which an anticrossing can occur in the absence of strong coupling. We study planar silver/dielectric structures and find that, around the epsilon-near-zero point in silver, the impedance matching between the silver and dielectric layers gives rise to an anticrossing. Our work shows that care must be taken to ensure that anticrossing arising from impedance matching is not misattributed to strong coupling.

All-optical control of phase singularities using strong light-matter coupling.

Strong light-matter coupling occurs when the rate of energy exchange between an electromagnetic mode and a molecular ensemble exceeds competing dissipative processes. The study of strong coupling has been motivated by applications such as lasing and the modification of chemical processes. Here we show that strong coupling can be used to create phase singularities. Many nanophotonic structures have been designed to generate phase singularities for use in sensing and optoelectronics. We utilise the concept of cavity-free strong coupling, where electromagnetic modes sustained by a material are strong enough to strongly couple to the material's own molecular resonance, to create phase singularities in a simple thin film of organic molecules. We show that the use of photochromic molecules allows for all-optical control of phase singularities. Our results suggest what we believe to be both a new application for strong light-matter coupling and a new, simplified, more versatile means of manipulating phase singularities.

Agreement between three methods for measuring near point of convergence among patients with different refractive errors.

PURPOSE: To describe the agreement of three methods of Near Point of Convergence (NPC) measurement among patients with different refractive errors. METHODS: 60 asymptomatic subjects, 18 - 25 yrs old, were included in 3 groups: emmetropes, myopes and hypermetropes. All subjects underwent NPC break point and recovery point measurement by Royal Air Force (RAF) rule, Pencil Rule (PR) and penlight with red green glasses (RG) using standard techniques. The values obtained were compared within each group by Friedman test. Bland Altman plots were constructed and Limits of Agreement calculated. RESULTS: Hypermetropes performed poorly in RG test with significantly receded break point and recovery point values (10.30 ± 1.45cm, 13.13± 1.20cm) compared to RAF test (7.18 ± 1.86 cm, 10.15 ± 2.11cm ) and PR test (7.78 ± 1.75 cm, 10.75 ± 1.44cm). The recovery point values of the emmetropes with RG test (10.15 ± 2.32cm) was significantly receded compared to PR (9.30 ± 1.72 cm) and RAF test (Emm: 9.08 ± 2.30cm). The myopes performed better with PR test with significantly better recovery point values with PR test (8.70 ± 1.97 cm) compared to RAF (9.68 ± 2.08) and RG (9.45 ± 1.73) tests. The limits of agreement were wide suggesting disagreement between the tests. CONCLUSION: The RG test yields more receded results in hypermetropes compared to the RAF and PR tests, and the PR test yields better results than the RAF test in myopes. Thus, the results obtained by these different methods show a lack of agreement. The variability is not uniform in patients with different refractive errors.

Cavity-Free Ultrastrong Light-Matter Coupling.

Strong coupling between light and matter can occur when the interaction strength between a confined electromagnetic field and a molecular resonance exceeds the losses to the environment, leading to the formation of hybrid light-matter states known as polaritons. Ultrastrong coupling occurs when the coupling strength becomes comparable to the transition energy of the system. It is widely assumed that the confined electromagnetic fields necessary for strong coupling to organic molecules can only be achieved with external structures such as Fabry-Pérot resonators, plasmonic nanostructures, or dielectric resonators. Here we show experimentally that such structures are unnecessary and that a simple dielectric film of dye molecules supports sufficiently modified vacuum electromagnetic fields to enable room-temperature ultrastrong light-matter coupling. Our results may be of use in the design of experiments to probe polaritonic chemistry and suggest that polaritonic states are perhaps easier to realize than previously thought.

Single vs double anti-crossing in the strong coupling between surface plasmons and molecular excitons.

Strong coupling between surface plasmons and molecular excitons may lead to the formation of new hybrid states-polaritons-that are part light and part matter in character. A key signature of this strong coupling is an anti-crossing of the exciton and surface plasmon modes on a dispersion diagram. In a recent report on strong coupling between the plasmon modes of a small silver nano-rod and a molecular dye, it was shown that when the oscillator strength of the exciton is large enough, an additional anti-crossing feature may arise in the spectral region where the real part of the permittivity of the excitonic material is zero. However, the physics behind this double anti-crossing feature is still unclear. Here, we make use of extensive transfer matrix simulations to explore this phenomenon. We show that for low oscillator strengths of the excitonic resonance, there is a single anti-crossing arising from strong coupling between the surface plasmon and the excitonic resonance, which is associated with the formation of upper and lower plasmon-exciton polaritons. As the oscillator strength is increased, we find that a new mode emerges between these upper and lower polariton states and show that this new mode is an excitonic surface mode. Our study also features an exploration of the role played by the orientation of the excitonic dipole moment and the relationship between the modes we observe and the transverse and longitudinal resonances associated with the excitonic response. We also investigate why this type of double splitting is rarely observed in experiments.

A New Signature for Strong Light-Matter Coupling Using Spectroscopic Ellipsometry.

Light-matter interactions can occur when an ensemble of molecular resonators is placed in a confined electromagnetic field. In the strong coupling regime the rapid exchange of energy between the molecules and the electromagnetic field results in the emergence of hybrid light-matter states called polaritons. Multiple criteria exist to define the strong coupling regime, usually by comparing the splitting of the polariton bands with the line widths of the uncoupled modes. Here, we highlight the limitations of these criteria and study strong coupling using spectroscopic ellipsometry, a commonly used optical characterization technique. We identify a new signature of strong coupling in ellipsometric phase spectra. The combination of ellipsometric amplitude and phase spectra yields a distinct topological feature that we suggest could serve as a new criterion for strong coupling. Our results introduce the idea of ellipsometric topology and could provide further insight into the transition from the weak to strong coupling regime.

Comparison of torsional amplitudes between emmetropes and myopes using after-image slides.

Purpose: To describe the influence of corrected refractive error on measured torsional fusional amplitudes (TA) by comparing the TA between emmetropes and spectacle corrected myopes, using the after-image slides of the synoptophore, as targets. Methods: Fifty emmetropes (Group I) and 50 myopes (Group II) with best-corrected acuity of 6/6 in each eye were included in the study. Near point of convergence (NPC), near point of accommodation (NPA), and horizontal fusional amplitudes (HFA) were assessed in all the subjects. After-image slides, both horizontally aligned, were used as targets (without the bright flashes). One of the slides was rotated inwards, till cyclo-diplopia was reported by the subject; the procedure was repeated with the slide rotated outwards. The sum of the two readings was taken as TA. NPC, NPA, HFA, and TA were analyzed. Results: There was no significant difference in the NPC, NPA, and HFA between the two groups. The emmetropic subjects had significantly better torsional amplitude (8.4 ± 1.4 degrees) compared to myopes (7.7 ± 1.5 degrees, P = 0.03). We postulate that this difference may be due to perceived image minification, which brings the edges of retinal image of the targets closer to the fovea, thus rendering the myopes lesser tolerant to cyclodiplopia than emmetropes. Conclusion: Refractive error, corrected with spectacles, influences the measured TA. Myopic subjects have lesser torsional fusional amplitude than emmetropes.

Eighty Years of Mycopathologia: A Retrospective Analysis of Progress Made in Understanding Human and Animal Fungal Pathogens.

Mycopathologia was founded in 1938 to 'diffuse the understanding of fungal diseases in man and animals among mycologists.' This was an important mission considering that pathogenic fungi for humans and animals represent a tiny minority of the estimated 1.5-5 million fungal inhabitants on Earth. These pathogens have diverged from the usual saprotrophic lifestyles of most fungi to colonize and infect humans and animals. Medical and veterinary mycology is the subdiscipline of microbiology that dwells into the mysteries of parasitic, fungal lifestyles. Among the oldest continuing scientific publications on the subject, Mycopathologia had its share of 'classic papers' since the first issue was published in 1938. An analysis of the eight decades of notable contributions reveals many facets of host-pathogen interactions among 183 volumes comprising about 6885 articles. We have analyzed the impact and relevance of this body of work using a combination of citation tools (Google Scholar and Scopus) since no single citation metric gives an inclusive perspective. Among the highly cited Mycopathologia publications, those on experimental mycology accounted for the major part of the articles (36%), followed by diagnostic mycology (16%), ecology and epidemiology (15%), clinical mycology (14%), taxonomy and classification (10%), and veterinary mycology (9%). The first classic publication, collecting nearly 200 citations, appeared in 1957, while two articles published in 2010 received nearly 150 citations each, which is notable for a journal covering a highly specialized field of study. An empirical analysis of the publication trends suggests continuing interests in novel diagnostics, fungal pathogenesis, review of clinical diseases especially with relevance to the laboratory scientists, taxonomy and classification of fungal pathogens, fungal infections and carriage in pets and wildlife, and changing ecology and epidemiology of fungal diseases around the globe. We anticipate that emerging and re-emerging fungal pathogens will continue to cause significant health burden in the coming decades. It remains vital that scientists and physicians continue to collaborate by learning each other's language for the study of fungal diseases, and Mycopathologia will strive to be their partner in this increasingly important endeavor to its 100th anniversary in 2038 and beyond.

Traumatic chiasmal syndrome: A meta-analysis.

PURPOSE: To report a case presenting with bitemporal hemianopia due to traumatic chiasmal syndrome after head injury, and to compare the findings with individual case reports published in the literature. METHODS: A detailed search was made in PubMed, MedIND, Taylor and Francis online and Wiley online library databases for individual case reports of traumatic chiasmal syndrome. All the case reports were read in full and the findings summarized in a table, which included details of the case who presented with bitemporal hemianopia as an index case. RESULTS: All published cases of traumatic chiasmal syndrome appear to share some common features, such as injury to the frontal bone and fracture of the anterior skull base. Bitemporal hemianopia and visual acuity have a variable presentation, and do not appear to correlate with severity of injury. Isolated bitemporal hemianopia is rare and clinical improvement may or may not occur. CONCLUSIONS AND IMPORTANCE: Traumatic chiasmal syndrome should be considered as a differential diagnosis in patients presenting with bitemporal hemianopia after head injury causing frontal and anterior skull base fracture.

Inflammation and oxidative stress in corneal tissue in experimental keratitis due to Fusarium solani: Amelioration following topical therapy with voriconazole and epigallocatechin gallate.

Combined antifungal and antioxidant therapy may help to reduce oxidative stress in fungal keratitis. Experimental Fusarium solani keratitis was induced by application of F. solani conidia to scarified cornea (right eye) of 16 rabbits (another four rabbits were negative controls [Group I]). Five days later, F. solani-infected animals began receiving hourly topical saline alone (Group II), voriconazole (10 mg/mL) alone (Group III), epigallocatechin gallate (EGCG, 10 mg/mL) alone (Group IV) or voriconazole and EGCG (Group V). Twenty days post-inoculation, corneal lesions were graded. After animal sacrifice, excised corneas underwent histopathological and microbiological investigations. Corneal tissue levels/activities of interleukin 1 beta (IL-1ß) and tumour necrosis factor alpha (TNF-α) gene mRNA transcripts, matrix metalloproteinase (MMP) 2 and 9 proteins, malondialdehyde (MDA) and reduced glutathione (GSH), and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were also measured. Clinical and histopathological scores (severity of corneal lesions; [P < .05]) and mean levels (P < .05) of IL-1ß and TNF-α mRNA transcripts, MMP 2, MMP 9 and MDA were Group II > Groups IV and III > Groups V and I. Mean SOD, CAT, GPx and GSH levels (P < .05) were Group II < Groups IV and III < Groups V and I. Topical voriconazole with EGCG apparently reduces inflammation in experimental F. solani keratitis, as manifested by improved clinical, histological, microbiological and molecular parameters.

Cavernous hemangioma of the orbit: an unusual acute presentation.

We report an unusual presentation of an orbital cavernous hemangioma in a 26-year-old female, who noted sudden redness and swelling of the left eye (LE) on waking up. At presentation, upper eyelid edema with periorbital ecchymosis and subconjunctival hemorrhage were noted in the LE. Although there was transient symptomatic relief with topical medications, blurring of vision developed in the LE. When seen 10 days later, the patient's LE showed axial proptosis. Magnetic resonance imaging revealed an intraconal soft tissue mass in the superomedial quadrant of the left orbit. Superior orbitotomy with mass excision was done; histopathological examination of the excised mass revealed a cavernous hemangioma. The patient had complete visual recovery following surgery. To our knowledge, an acute presentation of an orbital cavernous hemangioma with subconjunctival hemorrhage and periorbital ecchymosis has not previously been reported.

In vitro antioxidant and anticataractogenic potential of silver nanoparticles biosynthesized using an ethanolic extract of Tabernaemontana divaricata leaves.

Silver nanoparticles (AgNPs) have been found useful in biological systems and in medicine since they possess a large surface area to volume ratio, which confers on them several unique properties. In the present study, AgNPs that had been biosynthesized using an ethanolic extract of Tabernaemontana divaricata leaf were evaluated for putative antioxidant potential and efficacy in preventing experimental in-vitro selenite-induced opacification of the ocular lens (cataractogenesis). The antioxidant potential of the AgNPs was evaluated in-vitro by looking for radical-scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2) free radicals as well as by determining reducing power. The anticataractogenic potential of the AgNPs was evaluated in an in-vitro model of selenite-induced cataractogenesis in five groups of Wistar rat lenses cultured in Dulbecco's modified Eagle's medium (DMEM) for 24h: Group I lenses (negative control) were cultured in DMEM alone; Group II lenses were exposed to sodium selenite alone (100µM); Group III lenses were exposed simultaneously to sodium selenite and the T. divaricata extract (250µg/ml); Group IV lenses were exposed simultaneously to sodium selenite and the biosynthesized AgNPs (125µg/ml); and Group V lenses were exposed to the AgNPs alone. In these lenses, gross morphological changes, as well as activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), and levels of reduced glutathione (GSH) and malondialdehyde (MDA), were determined. In-vitro, the AgNPs (which were spherical in shape with an average diameter ranging from 15 to 50nm) showed potent and concentration-dependent radical-scavenging activity on DPPH and H2O2 free radicals as well as reducing power. The gross morphological changes seen in the cultured rat lenses were: all eight control (Group I) lenses remained transparent; dense opacification was noted in all eight selenite-challenged untreated (Group II) lenses; in selenite-challenged, simultaneously T. divaricata extract-treated (Group III) lenses, no opacification occurred in seven of eight (87.5%) lenses and only minimal opacification in one (12.5%) lens; all the eight Group IV (selenite-challenged, simultaneously AgNPs-treated) lenses did not show any opacification; and all the eight Group V lenses (exposed to AgNPs alone) remained as transparent as control lenses. The mean activities of CAT, SOD, GPx and GST, and the mean levels of GSH, were significantly (p<0.05) lower in Group II lenses than those in Groups I, III, IV and V lenses, while the mean MDA level was significantly (p<0.05) higher in Group II lenses than those in Groups I, III, IV and V lenses; oxidative damage possibly occurred in Group II lenses, whereas this appears to have been prevented in Groups III and IV lenses. These observations suggest that the T. divaricata leaf ethanolic extract, and also the AgNPs biosynthesized using the T. divaricata extract, possess effective in-vitro antioxidant activity and the potential to prevent experimental selenite-induced opacification in cultured Wistar rat lenses.

Strong coupling of diffraction coupled plasmons and optical waveguide modes in gold stripe-dielectric nanostructures at telecom wavelengths.

We propose a hybrid plasmonic device consisting of a planar dielectric waveguide covering a gold nanostripe array fabricated on a gold film and investigate its guiding properties at telecom wavelengths. The fundamental modes of a hybrid device and their dependence on the key geometric parameters are studied. A communication length of 250 µm was achieved for both the TM and TE guided modes at telecom wavelengths. Due to the difference between the TM and TE light propagation associated with the diffractive plasmon excitation, our waveguides provide polarization separation. Our results suggest a practical way of fabricating metal-nanostripes-dielectric waveguides that can be used as essential elements in optoelectronic circuits.

Identification of phytoconstituents and in-vitro evaluation of the putative anticataractogenic effect of an ethanolic root extract of Leucas aspera.

Modern herbal medicine has played a significant role in treating oxidative stress and related complications. In the present investigation, gas chromatography-mass spectrometric analysis of ethanolic extracts of the leaf and of the root of Leucas aspera (L. aspera) (Willd.) Link separately showed the presence of various phytoconstituents; major components have already been reported to possess various biological, including antioxidant, activities. Of the two extracts analyzed, the root extract exhibited more potential antioxidant activity than did the leaf extract. Since this finding correlated with more perceptible amounts of antioxidant components being detected in the ethanolic extract of L. aspera root, the root extract was evaluated for possible anticataractogenic potential in cultured Wistar rat lenses. Following incubation of Wistar rat lenses for 24h at 37°C in Dulbecco's modified Eagle's medium (DMEM), gross morphological examination revealed that none of the eight lenses incubated in DMEM alone (Group I) exhibited any opacification (Grade 0), whereas all eight lenses incubated in DMEM that contained sodium selenite (100µM selenite/ml of DMEM) (Group II) exhibited thick opacification (Grade +++). In contrast, only one out of eight lenses incubated in DMEM containing sodium selenite (100µM selenite/ml of DMEM) and simultaneously exposed to the L. aspera root extract (300µg/ml of DMEM) (Group III) exhibited a slight degree of opacification (Grade +) after 24h incubation, while the remaining seven lenses did not show any opacification (Grade 0). The mean activities of catalase, superoxide dismutase, glutathione peroxidase and glutathione-S-transferase and the mean level of reduced glutathione were all significantly (p<0.05) higher in Group III lenses than the mean values in Group II lenses. The mean concentration of malondialdehyde in Group III lenses was significantly (p<0.05) lower than that in Group II lenses. Further, significantly (p<0.05) lower mean mRNA transcript levels of the genes encoding αA- and ßB1-crystallins, as well as significantly lower mean levels of the αA- and ßB1-crystallin proteins themselves, were observed in Group II lenses. However, in Group III lenses, the mean mRNA transcript levels of the crystallin genes, and the mean protein levels, were essentially similar to those noted in normal control (Group I) lenses. The results of the present study suggest that in selenite-challenged Wistar rat lenses simultaneously exposed to an ethanolic extract of L. aspera root, lenticular opacification was prevented by mean activities of enzymatic antioxidants, mean levels of reduced glutathione and malondialdehyde mean expression levels of genes encoding αA- and ßB1-crystallins, and mean levels of the crystallin proteins themselves, being maintained at near normal levels. Further studies are required to confirm whether the ethanolic extract of the root of L. aspera can be developed for pharmacological management of cataract.

Prospective, Randomized Clinical Trial of Povidone-Iodine 1.25% Solution Versus Topical Antibiotics for Treatment of Bacterial Keratitis.

PURPOSE: To compare povidone-iodine 1.25% ophthalmic solution with topical antibiotics for treatment of bacterial keratitis in areas of the world where use of effective topical antibiotics may not be an option. STUDY DESIGN: Randomized, controlled, investigator-masked clinical trial. METHODS: We randomized 172 individuals with bacterial keratitis to topical treatment with povidone-iodine or antibiotics (neomycin-polymyxin B-gramicidin in the Philippines; ciprofloxacin 0.3% in India). Using survival analysis, we compared intervals from start of treatment to "presumed cure" (primary outcome measure, defined as a closed epithelial defect without associated inflammatory signs) and to "recovering" (residual epithelial defect <1 mm2 with only minimal inflammation). RESULTS: Median interval to presumed cure in the Philippines was 7 days for povidone-iodine and 7 days for neomycin-polymyxin B-gramicidin (95% confidence interval [CI] for difference in median interval, -9.5 to 0.7 days) and in India was 12 days for povidone-iodine and 17 days for ciprofloxacin (95% CI, -35.2 to 3.2 days). Hazard ratio (HR) for presumed cure among those treated with povidone-iodine (vs antibiotics) was 1.46 in the Philippines (95% CI, 0.90-2.36; P = .13) and 1.70 in India (95% CI, 0.73-3.94; P = .22). Comparisons of intervals to recovering and HR for recovering also revealed no significant differences between treatment groups in either country. CONCLUSIONS: There is no significant difference between the effect of topical povidone-iodine 1.25% and topical antibiotics commonly available in the developing world for treatment of bacterial keratitis. Povidone-iodine 1.25%, which is widely available and inexpensive, can be considered for treatment of bacterial keratitis when antibiotic treatment is not practical.

Comparison of ultrasound biomicroscopy and ultrasonographic parameters in eyes with phacomorphic glaucoma and eyes with mature cataract.

PURPOSE: To compare data on anatomical and biometric parameters, and their combination, obtained by using ultrasound biomicroscopy (UBM) and A-scan in eyes with phacomorphic glaucoma (PG) and eyes with mature cataract and to determine differences that may predispose to development of PG. METHODS: Eighty patients (80 eyes) were enrolled in this cross-sectional study. Anterior chamber parameters, namely anterior chamber depth (ACD), angle-opening distance (AOD), iris-lens contact distance (ILCD), and trabecular-ciliary process distance (TCPD), among other parameters, were assessed by UBM (35 MHz), while axial length (AL) and lenticular thickness (LT) were determined by A-scan biometry. Absolute lenticular position (ALP) and relative lenticular position (RLP) were also compared. RESULTS: The mean AL of eyes with PG was less (P = 0.64) than the mean AL of eyes with mature cataract. The mean ILCD value in eyes with PG (1.30 ± 0.78 mm) was significantly higher (P = 0.0015) than that in eyes with mature cataract (0.86 ± 0.32 mm). The mean AOD value in eyes with PG (0.15 ± 0.10 mm) was significantly lower (P < 0.0001) than that in eyes with mature cataract (0.23 ± 0.06 mm); similarly, the mean RLP value in eyes with PG (0.20 ± 0.02) was significantly lower (P < 0.0001) than that in eyes with mature cataract (0.17 ± 0.02). TCPD showed negative correlation with LT r = -0.514; P = 0.017, r 2 = 0.264, in eyes with phacomorphic glaucoma and mature cataracts showed significant negative correlation of ILCD with AL (r = -0.575; P = 0.025, r 2 = 0.330). CONCLUSION: The results of UBM examination suggest that there are multiple mechanisms underlying the pathophysiology of PG, namely crowding of the anterior segment, increased iris-lens contact distance, and a more pronounced anterior shift of the lens. Simultaneous evaluation of anatomic and biometric parameters can improve diagnostic accuracy in predicting cases at risk for PG.