Evaluation of Eyeball and Orbit in Relation to Gender and Age

The investigation of cranial fossae in the intracranial cavity of fixed cadaveric skull bases: associations with sex, laterality, and clinical significance

PURPOSE

Our study aims to investigate three parts of the intracranial cavity, their distances to essential anatomical landmarks, and the correlations between these distances with sex, laterality, and surgical significance.

METHODS

The cranial nerve foraminae and essential surgical landmarks of each fossa were investigated bilaterally in 30 adult formalin-fixed cadaveric heads. Measurements, including lengths, depths, diameters, and horizontal distances to each other, to the midline of the skull, and to the outer lateral margin of the skull, were recorded on both sides.

RESULTS

The optic canal (OC) depth, internal auditory meatus (IAM) width, CNVII and CNIX diameters, and accessory hypoglossal canal (HC) distance were significantly greater on the left side (p < 0.05). CNVI length, CNV diameter, CNXI length, and the distances of the HC and accessory HC from the skull were significantly greater on the right side (p < 0.05). In males, correlations were found between the length of the left CNVIII and the right IAM diameter (r = 0.864, p = 0.001), right CNVIII length (r = 0.709, p = 0.022), right accessory HC length (r = 0.847, p = 0.016), and right-sided skull distance (r = 0.829, p = 0.042). In females, correlations were noted between IAM depth and length, right IAM location relative to the skull, left CNIX and CNX lengths, left CNXII length, left accessory HC location relative to the skull, and accessory HC length.

CONCLUSIONS

The findings of the current study indicate inherent asymmetry, sexual dimorphism, and variability in certain cranial nerves among cadaveric heads, which could have implications for surgical procedures, neuroanatomical studies, and clinical assessments. The study revealed side disparities and correlations within cranial fossa formations and essential surgical landmarks in both genders.

Anatomical variations of foramen of the diaphragma sellae and neighboring structures: a cadaveric study

The aim of our study was to examine the variations and types of foramen of diaphragma sellae (FDS) and their relationship with nearby surgical landmarks on cadavers.Twenty adult (9 male, 11 female) formalin-fixed cadaveric heads were bilaterally used to analyze the anatomical relationships around the supradiaphragmatic region of sella turcica. Lengths and distances of nearby surgical landmarks were measured by a digital microcaliper. SPSS version 25 was used to analyze the comparison between genders and body sides. Dorsum sellae distances to tuberculum sellae and the optic chiasm(OC) were higher in males than females (p < 0.05). Type 8 infundibulum passage was the most common variation with 50%. There was no finding related to types 1-4 of infundibulum passage. Thus, the present study has indicated that the infundibulum passes mostly from the posterior half of the foramen. The shape of the foramen was irregular in 45%, circular in 20%, sagittally oval in 20%, and horizontally oval in 15% of the cases. The OC was noted normal in 60%, prefixed in 35%, and postfixed in 5% of the cases. Comprehensive anatomical knowledge about the types of the FDS and their neighboring structures is crucial for preoperative planning of sellar region diseases in terms of navigating the region when accessing the foramen. Discrimination of variations of FDS, OC, and pituitary stalk, their relationships, and differences between genders is useful to minimize potential surgical complications.

Three-Dimensional (3D) Analysis of Orbital Morphometry in Healthy Anatolian Adults: Sex, Side Discrepancies, and Clinical Relevance

Background and objective The complex structural integrity of the orbit is crucial for visual functions. Three-dimensional (3D) reconstructions from radiological images have revolutionized anatomical understanding, eliminating the limitations of two-dimensional (2D) imaging and offering intricate spatial details for complex structures. The aim of this study was to analyze the detailed morphometry of the orbit in healthy Anatolian adults, considering sex, side discrepancies, and clinical relevance using 3D models reconstructed from multidetector computed tomography (MDCT) images. Materials and methods Fifty-six (44.44%) males and 70 (55.56%) females (total: 126, mean age: 48.62) MDCT images were randomly selected and 3D skull models were reconstructed using 3D Slicer software. Measurements were conducted in millimeters (mm) for transverse and vertical diameters, circumference of the orbital opening, orbital wall lengths, as well as intraorbital and extraorbital distances. Results The method of measurements showed high reproducibility of results. The mean values for transverse and vertical diameters, circumference of the orbital opening, medial and lateral wall lengths, roof and floor lengths, and intraorbital and extraorbital distances were 40.23±2.12 mm (p<0.001), 34.94±2.16 mm (p=0.365), 44.74 ±3.02 mm (p<0.001), 46.30±2.69 mm (p<0.001), 51.26±2.91 mm (p<0.001), 49.01±3.22 mm (p<0.001), 126.10±5.71 mm (p<0.001), 19.63±2.35 mm (p=0.026), and 94.09±4.84 mm (p<0.001), respectively. Conclusion The study's high measurement reproducibility contributes significantly to the existing literature and clinical practice. These findings offer specific insights into Anatolian orbital morphometry, aiding in surgical planning, implant placement, and diagnostic assessments. The precise measurement values serve as a reliable reference for clinicians, facilitating the identification of normal and abnormal orbital anatomy and enhancing patient care. We believe this study provides valuable data for craniofacial and ophthalmological research, benefiting both clinical practice and future research endeavors in these fields.

Normative orbital measurements in an Australian cohort on computed tomography

PURPOSE

To determine the normal diameters of the extraocular muscles (EOMs) and optic nerve sheath complex (ONSD) and correlate with patient demographics in an Australian cohort.

METHODS

Consecutive patients who underwent contrast enhanced computed tomography (CT) orbits between December 2017 and March 2021 were included. Patients with bilateral disease, previous orbital surgery, or poor scan quality were excluded. Normal orbit was used in patients with unilateral orbital disease.

RESULTS

Two hundred one orbits from 201 patients were included. Normal measurements (mean ± SD) were as follows: medial rectus (MR) 4.22 ± 0.56 mm; inferior rectus (IR) 4.20 ± 0.70 mm; lateral rectus (LR) 3.40 ± 0.56 mm; superior muscle group (SMG) 4.13 ± 0.72 mm; superior oblique (SO) 2.60 ± 0.43 mm; inferior oblique (IO) on quasi-sagittal plane 2.19 ± 0.42 mm, and the ONSD 5.62 ± 0.82 mm. The mean diameters of the LR, SMG, IR, SO, and ONSD were significantly larger in male than female patients (p < .05). Statistically significant correlation was found between age and the diameters of the LR (r = 0.29, p < .01), SMG (r = 0.22, p < .01), IO on a coronal plane (r = -0.18, p < .01), and ONSD (r = 0.16, p = .02).

CONCLUSION

This normative data may be used to diagnose pathological enlargement of the optic nerve and extraocular muscles, including involvement of the oblique muscles.

Virtual reconstruction of midfacial bone defect based on generative adversarial network

BACKGROUND

The study aims to evaluate the accuracy of the generative adversarial networks (GAN) for reconstructing bony midfacial defects.

METHODS

According to anatomy, the bony midface was divided into five subunit structural regions and artificial defects are manually created on the corresponding CT images. GAN is trained to reconstruct artificial defects to their previous normal shape and tested. The clinical defects are reconstructed by the trained GAN, where the midspan defects were used for qualitative evaluation and the unilateral defects were used for quantitative evaluation. The cosine similarity and the mean error are used to evaluate the accuracy of reconstruction. The Mann-Whitney U test is used to detect whether reconstruction errors were consistent in artificial and unilateral clinical defects.

RESULTS

This study included 518 normal CT data, with 415 in training set and 103 in testing set, and 17 real patient data, with 2 midspan defects and 15 unilateral defects. Reconstruction of midspan clinical defects assessed by experts is acceptable. The cosine similarity in the reconstruction of artificial defects and unilateral clinical defects is 0.97 ± 0.01 and 0.96 ± 0.01, P = 0.695. The mean error in the reconstruction of artificial defects and unilateral clinical defects is 0.59 ± 0.31 mm and 0.48 ± 0.08 mm, P = 0.09.

CONCLUSION

GAN-based virtual reconstruction technology has reached a high accuracy in testing set, and statistical tests suggest that it can achieve similar results in real patient data. This study has preliminarily solved the problem of bony midfacial defect without reference.

Measurement of 0 to 2 age normal eyeball volume by the use of multidetector computed tomography

Aim: To diagnose microphthalmia or macrophthalmia, it is necessary to know the normal reference values of the eyeball volumes. However, we do not have a table of normal reference values to evaluate normal eyeball volume at 0-2 years of age. To compensate for this deficiency, we aimed to detect normal eyeball volumes in the age group of 0-2 years with multidetector computed tomography (MDCT). Material and Method: A total of 90 patients who underwent MDCT with a prior diagnosis of head trauma but without traumatic pathology were included in the study. Patients were divided into age groups of 0-1 months, 2-6 months, 7-12 months, 13-24 months. The mean values of patients in each age group were examined with a 95% confidence interval. The correlation between bilateral eyeball volumes and age was calculated using the Pearson correlation test. The relationship between the age groups and the volume of the eyeball was studied using one-way ANOVA test. The relationship between eyeball volumes and sex was evaluated using the Mann Whitney U test. Results: Mean eyeball volume was measured as 3.91±0.54 cm3 for 0-1 months, 4.44 ±0.66 cm3 for 2-6 months, 5.81 ±0.68 cm3 for 7-12 months, and 5.83±1.09 cm3 for 13-24 months. A strong positive correlation was observed between eyeball volume and age (p < 0.001). There was no statistically significant relationship between eyeball volume and sex (p > 0.05). No statistically significant difference was observed between right eyeball volume and left eyeball volume ( p> 0.05). Conclusions: The increase in eyeball volume is most rapid in the first year of life. In this study, the reference eyeball volumes were determined in order to properly assess this rapid increase.

Anatomical study of the scleral ring and eyeball of the long-eared owl (Asio otus) with anatomical methods and diagnostic imaging techniques

BACKGROUND

The scleral ring in birds consists of ossicles that are fixed as small plates by cartilage joints and have no articulation to other parts of the skeleton.

OBJECTIVE

Due to inadequate examination of the scleral ring anatomy and its specific form in owls, this study aimed to investigate the exact structure of the scleral ring and some morphometric characteristics of the eyeball in a long-eared owl (Asio otus).

METHODS

The eyes of 20 alive and 10 dead male and female owls were examined. In addition to common anatomical methods, computed tomography scans and radiographic and ultrasonographic imaging techniques were used in this study.

RESULTS

The structure consisted of 15 ossicles. In the ventral part of the ring, these tubercles were observed in the scleral rings of all owls; in each ring, there were four bones with these tubercles. Additionally, there was no significant difference between the left and right eye parameters. Most ocular parameters in female owls were larger than those in males, but in the case of some parameters, such as optic nerve length and optic nerve sheath diameter, this difference was not observed.

CONCLUSIONS

According to this study, the scleral ring in the Asio otus has anterior and posterior parts, and the lens is in the immediate vicinity of the anterior part. The right and left scleral rings and eyeballs are bilaterally symmetrical in terms of the shape, size, and number of ossicles that form the ring.

Reappraisal of the types of hypoglossal canal: endocranial approach

This study aims to classify the endocranial variations inside the Hypoglossal Canal (HC) and evaluate the elements of the HC region in terms of sizes, diameters, and distances to the nearby surgical landmarks. The present study was done on 18 adult human fixed cadaver heads bilaterally. The internal opening of HC was examined for the presence of dural or osseos septations in the canal and was classified into five types (Type 1-5). The dimensions of hypoglossal nerve (CN XII) and the distance of intracranial openings of HC from the jugular foramen and jugular tubercle were measured. The prevalence of endocranial HC types were determined on both sides as follows: type 1 (23.53% left, 6.25% right), type 2 (37.5% right, 5.88% left), type 3 (52.94% left, 25% right), type 4 (18.75% right, 17.65% left), type 5 (12.5% right). Understanding the endocranial HC types is crucial for neurosurgeons in the differential diagnosis of various intracranial pathologies for the posterior cranial fossa approach. Knowing the anatomical relationships between the adjacent structures and symmetrical organization of the HC according to the types is crucial in determining surgical strategies and preserving adjacent structures.

Biometry of the human cornea and globe: An evaluation by age, gender and population

The purpose of this study was to examine the effects of age, gender and population origin on human globe and corneal dimensions and to explore the relationships between the dimensions. Human post-mortem eyes were obtained in Hyderabad (n = 223; range, 0-85 years) and Miami (n = 486; range, 6-103 years). The eyes were freed of extraneous tissues and globe antero-posterior length (GAPL), mean globe diameter (MGD) (average of horizontal and vertical), and corneal horizontal (HCD) and vertical (VCD) diameters were measured using digital calipers. The relationships of age, gender and population origin with globe and corneal dimensions and the relationships between the dimensions were assessed by bivalent and multiple regression analyses. Globe and cornea dimensions increase asymptotically with age until around the late teens but do not change thereafter. Bivariate and multivariate regression analysis of the >20-year-old eyes showed that population was significantly correlated with GAPL, MGD. HCD and VCD. Male globes and corneas were larger than those from females, but the difference did not appear to be statistically significant. All Hyderabad dimensions were significantly larger than those from the Miami. Neither GAPL nor MGD were correlated with the corneal dimensions. GAPL was significantly correlated with MGD as was HCD with VCD.

Developmental changes of the facial skeleton from birth to 18 years within a South African cohort (A computed tomography study)

Skeletal remains are often found on a crime scene in which a forensic anthropologist is then consulted to create a biological profile, which includes the estimation of age, sex, ancestry and stature. The viscerocranium plays an important role in the formation of a biological profile. However, to utilise the viscerocranium for age estimation, population specific normative data and knowledge of the development of the viscerocranium is required. Therefore, this study aimed to investigate the developmental changes from birth to 18 years of age of the facial skeleton of individuals from a South African cohort. This study comprised of 239 computed tomography (CT) scans (128 males; 111 females). The viscerocranium was subdivided into five regions viz.: orbital, nasal, midfacial, maxillary and mandibular. The linear parameters in each region were correlated to age to identify the developmental growth patterns of the viscerocranial regions according to male and female. The measurements which displayed the highest correlations with age were used to develop formulas which could be used for age estimation. The results of this study showed that the measurements in the orbital, midfacial, maxillary and mandibular regions experienced rapid growth between 0 and 5 years of age, with the nasal region increasing steadily over time. It was noted that males displayed overall larger measurements than females except for the anterior interorbital distance and both right and left zygomatic arch lengths (ZAL). Although only the left orbital height, nasal aperture height and mandible width displayed statistically significant size differences according to sex (p ≤ 0.05). The measurements which showed the highest correlations to age were the zygomatic arch distance (r = 0.8842, p < 0.001), ZAL (right: r = 0.8929, p < 0.001; left: r = 0.8656, p < 0.001) and the mandible width (r = 0.8444, p < 0.001). Formulas were derived for the measurements that could be used to forensically estimate age within a subadult cohort.

Orbital Growth is Associated with Eyeball Size: A Study Using CT-based Three-dimensional Techniques

AIM OF THE STUDY

This study was aimed to investigate the growth patterns and the relationship of the eyeball and the orbit using computed tomography (CT)-based three-dimensional (3D) techniques.

MATERIALS AND METHODS

A total of 175 Chinese patients who had undergone craniofacial or orbital CT scans were enrolled. This study only included data from the unaffected eye and orbit. Images were processed using 3D reconstruction to obtain the eyeball and the orbit parameters.

RESULTS

In early postnatal years, the sizes of eyeball and orbit increased significantly with age (p < 0.001) and reached a turning point at a critical age (8.967 and 12.800 years for the eyeball and orbit volume, respectively). The orbital index and orbital depth index, showing the shape of the orbital aperture and walls, decreased significantly with age (p < 0.001). In all ages, the orbit size was correlated with eyeball size (p < 0.001). The eye-orbit index, equivalent to the ratio of eye volume to orbital volume, declined steadily with age (p < 0.001).

CONCLUSIONS

The eyeball and orbit developed rapidly in early postnatal years, and then matured at a critical age. The eyeball size significantly contributed to the orbital growth; this contribution may be reduced as the eye-orbit index decreased with age. To the best of our knowledge, this is the first report on the growth and interrelation of the eyeball and the orbit using CT-based 3D techniques.

Correlation of Automated Computed Tomography Volumetric Analysis Metrics With Motility Disturbances in Thyroid Eye Disease

PURPOSE

The authors sought to examine relationships between CT metrics derived via an automated method and clinical parameters of extraocular muscle changes in thyroid eye disease (TED).

METHODS

CT images of 204 orbits in the setting of TED were analyzed with an automated segmentation tool developed at the institution. Labels were applied to orbital structures of interest on the study images, which were then registered against a previously established atlas of manually indexed orbits derived from 35 healthy individuals. Point-wise correspondences between study and atlas images were then compared via a fusion algorithm to highlight metrics of interest where TED orbits differed from healthy orbits.

RESULTS

Univariate analysis demonstrated several correlations between CT metrics and clinical data. Metrics pertaining to the extraocular muscles-including average diameter, maximum diameter, and muscle volume-were strongly correlated (p < 0.05) with the presence of ocular motility deficits with regards to the superior, inferior, and lateral recti (with exception of superior rectus motility deficits being mildly correlated with muscle volume [p = 0.09]). Motility defects of the medial rectus were strongly correlated with muscle volume, and only weakly correlated with average and maximum muscle diameter.

CONCLUSIONS

The novel method of automated imaging metrics may provide objective, rapid clinical information which may have utility in prevention and recognition of visual impairments in TED before they reach an advanced or irreversible stage and while they are able to be improved with immunomodulatory treatments.

Sex and Age Determination by Measurement of Foramen Magnum Dimensions on Computer Tomography Scanning Study in the Iranian Population

BACKGROUND

Individual distinguishing evidence may be an imperative field of measurable investigation which demonstrates higher correct expectation rates. This process of recognizable Evidence is facilitated by the assurance of sex and age. In circumstances where there are fragmented and mangled skeletal remains, sex assurance is moderately troublesome, and it becomes important to set up the precision of cadaver bones. Therefore, this study aims to evaluate sexual dimorphism and age determination by measuring foramen magnum (FM) dimensions in the Iranian population using digital computed tomography scan.

METHODS

The study sample consisted of a modern adult Iranian population of 120 males and 109 females (age range: 15-50 years). Length, width, and area of FM, also FM index were measured on base skull computed tomography scan.

RESULT

All of the parameters of FM (length, width, area, and FM index), were larger in men than women. The accuracy of sex determination was up to 50.2. The highest accuracy for sex determination was FM width (67.9). This study also helps craniofacial surgeon for exact reference value of FM, which are authorize neurosurgeons' accessibility to the brain stem approach and FM region with minimum retraction.

CONCLUSIONS

It can be concluded from the result, that morphometric analyze of FM is useful for sex determination but cannot be suitable for age determination.

Lateralization bias for autoimmune optic neuritis

The asymmetrical structure of the human brain is reflected not only by innate interhemispheric differences but also by lateralization in neurological disease. We tested if unilateral autoimmune optic neuritis (aON) manifests more frequently on the left than the right eye in clinical and neuroimaging terms and whether Google searches for aON symptoms reflect this bias, too. We employed a retrospective analysis of a patient cohort from 2009 to 2019 with 552 unilateral aONs and 374 corresponding MRI imaging data sets. Searchmetrics Suite keywords tool was applied for the analysis of Google searches on aON-symptoms in Germany, the US and the UK for the last 12 months. Left eye aON manifestations were more frequent than right aON manifestations (55.3% vs. 44.7%, p = 0.015) and 1.9 times more likely to be associated with a pathological MRI finding in the affected optic nerve (p = 0.013). Keywords describing aON-typical but not other ocular symptoms were more frequently associated with Google searches for the left in comparison to the right eye (p < 0.001). Autoimmune optic neuritis more frequently affects the left than the right eye and people search on the Internet more often for left-sided aON symptoms. Although a reporting bias due to an increased perception of left eye symptoms is one possible explanation, MRI evidence of more frequent optic nerve affection for the left in comparison to the right side suggests a leftward lateralization bias similar to the one previously shown for cerebral neuroinflammatory lesions.

Reappraisal of the types of trigeminal porus and importance in surgical applications

OBJECTIVE

The detailed information regarding the types of trigeminal porus (TP) and related surgical approach is lacking in the literature. Therefore, we performed this study to elucidate further the types of TP and the relationships with critical surgical landmarks in the skull base.

METHODS

The study was performed on 19 formalin-fixed cadavers of the cranial base (52.6% male, n = 10; 47.4% female, n = 9) on both sides. Calculations were made of the vertical dimension (VD), horizontal dimension (HD), and types of TP, the thickness of the TP, the HD and VD of the internal acoustic meatus, the distance between the TP-IAM, the thickness of the ossifying tissue that forms the TP, the trigeminal nerve (CN V) in both types and the distance between the CN V-VI.

RESULTS

The elliptical (42.1% left, 36.8% right), oval (52.6% left, 36.8% right) and slit-like (5.3% right) types of TP were detected (X² = 11.722). The HD of the TP was, on average, 8.02 mm (female) and 9.2 mm (male) on the right side, and 8.26 mm (female) and 8.81 mm (male) on the left side. The VD of the TP was, on average, 1.99 mm (female) and 2.65 mm (male) on the right side, and 2.42 mm (female) and 2.94 mm (male) on the left side.

CONCLUSIONS

In our study, ellipse and slit-like types of TP are taken into account in order to plan the surgical approaches to remove or prevent the extension of tumors. A combined surgical technique is recommended to reach the TP easily without damaging the nearby surgical structures during surgery. The oval type of TP allows a wide range of movements, so it is more advantageous in skull base surgery.

The eye as the discrete but defensible portal of coronavirus infection

Oculo-centric factors may provide a key to understanding invasion success by SARS-CoV-2, a highly contagious, potentially lethal, virus with ocular tropism. Respiratory infection transmission via the eye and lacrimal-nasal pathway elucidated during the 1918 influenza pandemic, remains to be explored in this crisis. The eye and its adnexae represent a large surface area directly exposed to airborne viral particles and hand contact. The virus may bind to corneal and conjunctival angiotensin converting enzyme 2 (ACE2) receptors and potentially to the lipophilic periocular skin and superficial tear film with downstream carriage into the nasopharynx and subsequent access to the lungs and gut. Adenoviruses and influenza viruses share this ocular tropism and despite differing ocular and systemic manifestations and disease patterns, common lessons, particularly in management, emerge. Slit lamp usage places ophthalmologists at particular risk of exposure to high viral loads (and poor prognosis) and as for adenoviral epidemics, this may be a setting for disease transmission. Local, rather than systemic treatments blocking virus binding in this pathway (advocated for adenovirus) are worth considering. This pathway is accessible with eye drops or aerosols containing drugs which appear efficacious via systemic administration. A combination such as hydroxychloroquine, azithromycin and zinc, all of which have previously been used topically in the eye and which work at least in part by blocking ACE2 receptors, may offer a safe, cost-effective and resource-sparing intervention.

Novel TMEM98, MFRP, PRSS56 variants in a large United States high hyperopia and nanophthalmos cohort

Nanophthalmos is a rare condition defined by a small, structurally normal eye with resultant high hyperopia. While six genes have been implicated in this hereditary condition (MFRP, PRSS56, MYRF, TMEM98, CRB1,VMD2/BEST1), the relative contribution of these to nanophthalmos or to less severe high hyperopia (≥ + 5.50 spherical equivalent) has not been fully elucidated. We collected probands and families (n = 56) with high hyperopia or nanophthalmos (≤ 21.0 mm axial length). Of 53 families that passed quality control, plausible genetic diagnoses were identified in 10/53 (18.8%) by high-throughput panel or pooled exome sequencing. These include 1 TMEM98 family (1.9%), 5 MFRP families (9.4%), and 4 PRSS56 families (7.5%), with 4 additional families having single allelic hits in MFRP or PRSS56 (7.5%). A novel deleterious TMEM98 variant (NM_015544.3, c.602G>C, p.(Arg201Pro)) segregated with disease in 4 affected members of a family. Multiple novel missense and frameshift variants in MFRP and PRSS56 were identified. PRSS56 families were more likely to have choroidal folds than other solved families, while MFRP families were more likely to have retinal degeneration. Together, this study defines the prevalence of nanophthalmos gene variants in high hyperopia and nanophthalmos and indicates that a large fraction of cases remain outside of single gene coding sequences.

[Gender medicine in ophthalmology : The "small difference" between women and men]

Gender-specific or sex-specific medicine is part of "personalized" medicine. After differences in heart diseases between women and men were first identified and increasingly published in the field of cardiology since the 1980s, differences between the sexes have also become the focus of interest in other disciplines. Immunological and hormonal aspects indicate significant differences, e.g. in the severity of the disease or the response to treatment. Even in ophthalmology epidemiological differences in some diseases are known but so far these do not lead to a different approach in the practical treatment of patients. This CME article aims to raise awareness of gender medicine also in the field of ophthalmology and at the same time to promote understanding of these differences by presenting the fundamental differences between the sexes.

Ranibizumab Population Pharmacokinetics and Free VEGF Pharmacodynamics in Preterm Infants With Retinopathy of Prematurity in the RAINBOW Trial

Purpose

To develop a population pharmacokinetic (PK) model for intravitreal ranibizumab in infants with retinopathy of prematurity (ROP) and assess plasma free vascular endothelial growth factor (VEGF) pharmacodynamics (PD).

Methods

The RAnibizumab compared with laser therapy for the treatment of INfants BOrn prematurely With retinopathy of prematurity (RAINBOW) trial enrolled 225 infants to receive a bilateral intravitreal injection of ranibizumab 0.1 mg, ranibizumab 0.2 mg, or laser in a 1:1:1 ratio and included sparse sampling of blood for population PK and PD analysis. An adult PK model using infant body weight as a fixed allometric covariate was re-estimated using the ranibizumab concentrations in the preterm population. Different variability, assumptions, and covariate relationships were explored. Model-based individual predicted concentrations of ranibizumab were plotted against observed free VEGF concentrations.

Results

Elimination of ranibizumab had a median half-life of 5.6 days from the eye and 0.3 days from serum, resulting in an apparent serum half-life of 5.6 days. Time to reach maximum concentration was rapid (median: 1.3 days). Maximum concentration (median 24.3 ng/mL with ranibizumab 0.2 mg) was higher than that reported in adults. No differences in plasma free VEGF concentrations were apparent between the groups or over time. Plotted individual predicted concentrations of ranibizumab against observed free VEGF concentrations showed no relationship.

Conclusions

In preterm infants with ROP, elimination of ranibizumab from the eye was the rate-limiting step and was faster compared with adults. No reduction in plasma free VEGF was observed. The five-year clinical safety follow-up from RAINBOW is ongoing.

Translational Relevance

Our population PK and VEGF PD findings suggest a favorable ocular efficacy: systemic safety profile for ranibizumab in preterm infants.

Intraforaminal Dural Septations of the Jugular Foramen: A Cadaveric Study

OBJECTIVE

The aim of this study was to define the types, prevalences, and diameters of dural septations (DSs) on the inner surface of the jugular foramen (JF) and to describe the distances between the JF, the glossopharyngeal nerve (cranial nerve [CN] IX), vagus nerve (CN X), and accessory nerve (CN XI), the internal acoustic meatus, and nearby surgical landmarks on cadaveric heads.

METHODS

Seventeen adult (9 men and 8 women) formalin-fixed cadaveric heads were used to analyze the types and prevalence of DS bilaterally. Diameters and distances between the DS and the adjacent CNs (CN IX-XI) were measured by digital microcaliper. The multiple t test (SPSS version 25) was used to analyze the comparison between both sides via diameters, numbers, distance, length, and thickness of DS.

RESULTS

The most frequent type of DS was type I (62.5%, right; 56.3%, left), followed by type II (18.8%, right; 25%, left), type III (12.5%, right; 6.3%, left), and type IV (6.3%, right; 12.5%, left). The mean diameter of the septum was 0.6-1 mm, and the mean length of the dural septa was 4.01 mm (right) and (3.83 mm) left. The difference in the length and thickness of the DS between the genders was statistically significant on both sides (P < 0.05). The DS-CN X and DS-JF distances of women were greater than those of men on the right side (P < 0.05).

CONCLUSIONS

The significant differences between dural septum types on the 2 sides of the body may indicate asymmetric location or a variant emerging site of CNs in the same individual.

The Relationship Between Ocular Protrusion and Craniofacial Structures

OBJECTIVE

This study aimed to evaluate the relationships between ocular protrusion and other craniofacial structures.

METHODS

The lateral cephalograms of 124 nonsyndromic white adults were assessed. Two orbital and 13 craniofacial parameters were measured. Subgroups were constructed according to sex, anteroposterior position of maxilla, and mandibular plane angle values.Anatomical parameters and their relationships were statistically analyzed by analysis of variance and multivariate stepwise regression analysis.

RESULTS

There were no significant differences in ocular protrusion distances between sexes, and between individuals with different maxillary anteroposterior position and mandibular plane angle values. Ocular protrusion distances, the distance between the eyeball apex and the lateral orbital margin (Eyeball apex-LOr: OP1) and inferior orbital margin (Eyeball apex-IOr: OP2), were found to be 20.6 ± 2.8 and 16.5 ± 3.1, respectively. However, regression analysis showed that the ocular protrusion distances had weak correlation with a few craniofacial structures. The OP1 had a low negative relationship with the maxillary anteroposterior position (N-Aperp) (r: -0.289) (P < 0.05). The OP2 had a low negative relationship with the palatal plane angle (FH/PP) (r: -0.291) (P < 0.01) but had a positive relationship with the cranial base angle (BSN) (r: 0.304) (P < 0.01) and posterior facial height (SGo) (r: 0.299) (P < 0.01).

CONCLUSIONS

Ocular protrusion distances did not differ by sex, maxillary anteroposterior position, and amount of mandibular plane angle and showed weak correlation with a few craniofacial structures. Ocular protrusion amounts can be used for diagnosis and treatment plan in craniofacial syndromic or nonsyndromic anomalies.

Risk Factors for Glaucoma Drainage Device Exposure in a Middle-Eastern Population

PRéCIS:: In this case-control study, female sex, and older age were risk factors for tube exposure; risk was related to the number of prior ocular surgeries and scleral patch graft (compared with pericardial graft) was found to protect against exposure.

PURPOSE

Identification of potential risk factors for glaucoma drainage device (GDD) exposure may help to prevent this potentially blinding complication. The purpose of this study was to evaluate the possible risk factors for GDD exposure in a tertiary eye care center in the Middle-East.

METHODS

A retrospective case-control study was undertaken for a 7-year period (2008 to 2015 inclusive). All patients who presented with a GDD incident exposure were identified and were compared with a similar number of controls (without exposure) identified during the same period. Demographic factors, past ocular history, treatment, and surgical technique were recorded for both groups. Bivariate and multivariable analyses were used to identify possible risk factors for tube exposure.

RESULTS

A total of 836 patients underwent GDD surgery during this time period and 53 patients were identified with exposure, giving a cumulative incident exposure rate of 6.3% (0.9% per year). Bivariate analysis showed that the median age of cases (51 years) was similar to controls (53 years) (P=0.95), while there was a greater proportion of women with exposure (49%) compared with the control group (28%) with a statistically significant difference (P=0.028). The number of previous surgeries (3.77±2.1) was significantly higher (P=0.018) in the exposure group (4.25±2.0) compared with controls (3.3±2.0). With each unit increase in the number of previous surgeries, the odds of exposure significantly increased by 1.29 (95% confidence interval, 1.05-1.57). In the multivariable regression, female sex (P=0.006) and older age (P=0.025) were significant risk factors and use of a scleral patch (P=0.02) graft potentially protective.

CONCLUSIONS

Previous surgery, female sex, and older age are potential risk factors identified in our study. The use of scleral patch graft is potentially protective against GDD extrusion. Further study is needed to elucidate the reasons for these causative and protective factors.

Interocular Symmetry of Fixation, Optic Disc, and Corneal Astigmatism in Bilateral High Myopia: The Shanghai High Myopia Study

Purpose

We investigate the interocular symmetry of fixation, optic disc, and corneal astigmatism in bilateral high myopia, and evaluate the predictive relationships between them.

Methods

We enrolled 202 cases with bilateral high myopia. Fixation, in terms of the bivariate contour ellipse area (BCEA), was evaluated with the Macular Integrity Assessment microperimetry. Optic disc features, including orientation, tilt, and rotation, were evaluated with ultrawide-field retinal photographs. Corneal topography was performed with Pentacam. Interocular symmetry of fixation, optic disc, and corneal astigmatism was assessed, and the predictive relationships between these parameters were investigated.

Results

Axial length differences between the two eyes were: ≥0 to ≤1 mm, 67.8%; 1 to ≤2 mm, 20.3%; 2 to ≤3 mm, 9.4%; and >3 mm, 2.5%. Axial length, 95% BCEA, and magnitude of corneal astigmatism showed good interocular symmetry, whereas the optic disc tilt, rotation, and axis of corneal astigmatism (mirror axes) showed less symmetry (all P < 0.05). No interocular symmetry was observed in the direction of the fixation ellipse. In both eyes, the corneal steep meridian more often was consistent with the optic disc orientation than inconsistent (right eye [OD], P < 0.001; left eye [OS], P = 0.029).

Conclusions

As different parameters presented different degrees of symmetry, cautions are needed when including both eyes or only one lateral eye in cases of bilateral high myopia for clinical investigations. The optic disc orientation, to some extent, may indicate the steep meridian of the cornea.

Translational Relevance

Our study provided evidences for selection of eye laterality in clinical investigations of highly myopic eyes.

Sphenoid Sinus in Relation to Age, Gender, and Cephalometric Indices

The sphenoid sinus is located in the center of the cranial base and is surrounded by numerous neurovascular structures. The aim of this study was to determine sphenoid sinus types and subtypes, dimensions of the sinus and cranium, and the relations of these to age and gender.Computed tomography data was obtained from 144 patients to determine right sphenoidal volume (sphVOLR), left sphenoidal volume (sphVOLL), total sphenoidal volume (sphVOLT), anteroposterior length of the sphenoid sinus (sphAP), laterolateral length of the sphenoid sinus (sphLL), head circumference (crHC), fronto-occipital length (crFO), and biparietal length (crBP), with OSIRIX software. The patients' ages ranged between 9 and 83 years (mean age 38 ± 15.5 years). The study included 89 males (mean age 39 ± 15.5 years) and 55 females (mean age 38 ± 15.6 years).Conchal (1.4%), presellar (8.3%), sellar (23.6%), and postsellar (66.7%) type sphenoid sinuses were determined based on the extension of pneumatization around the sella turcica. Each type of sphenoid sinus was classified into the following 5 types based on the direction of pneumatization: body, full lateral, pterygoid, lesser wing, and greater wing subtypes. Mean sphAP was determined as 29.72 mm and mean sphLL as 37.73 mm. In 5 patients only (3.4%), the sphenoid sinus was not divided into right and left by the intersphenoidal septum.The variations in the extensions of pneumatization of the sphenoid sinus and its dimensions might be used to estimate the selection of a surgical approach to lesions bordering the sinus.

Facial approximations: Characteristics of the eye in a South African sample

Although guidelines for facial approximations, including those for the eye, are in use in South Africa, limited data on African populations exist to confirm its validity. As precise placement of the eyes in facial approximations is of importance for facial recognition, this study tested established guidelines by measuring specific instrumental dimensions. Forty-nine cadavers from the Sefako Makgatho Health Sciences University and the University of Pretoria were dissected to determine the position of the canthi and the size and position of the eyeball in the orbit. Thirty cone beam computer tomography scans and 30 computer tomography scans from the Oral and Dental and Steve Biko Hospitals respectively were used to determine the size of the eyeball. Results from this study were compared to the published guidelines. The most prominent discrepancies included a more rectangular shape of the orbit, an oval shaped eyeball and a different position of the canthi. In African faces, the medial canthus was found to be located higher than the lateral canthus. The distance between the endocanthion and superior orbital margin was 17.7mm and the exocanthion and superior orbital margin 19.5mm. Inter-population differences may have an effect on facial approximations and its accuracy as is often demonstrated in practice. The findings of this study should be taken into consideration when designing population specific guidelines for reconstruction of the eye in South Africans of African ancestry.

Porous orbital implant after enucleation in retinoblastoma patients: indications and complications

This study aims to identify risk factors associated with complications in retinoblastoma patients following primary and secondary enucleations with porous implant placement. A retrospective case-control study was performed between 2010 and 2015. Data pertaining to subjects' demographics, medical history, clinical, and pathological findings, implant characteristics and complications were collected. The analysis included 103 eyes of 101 patients age 27.8 ± 21.9 months undergoing enucleation for retinoblastoma. Postoperatively, 19/103 (18%) eyes developed exposure, extrusion, or hematoma requiring subsequent surgery. Exposure was the most common postoperative complication (12/19, 63%). Age at enucleation 24 months or younger, Hispanic ethnicity, female gender, and intravenous chemotherapy prior to enucleation were associated with increased odds of implant complications. In contrast, patients who were given intravitreal melphalan (IM), subtenons carboplatin (SC), or external beam radiation therapy (EBRT) did not demonstrate an increased risk of complications. In this cohort of retinoblastoma patients undergoing primary or secondary enucleation with porous implants, implant exposure was the most common postoperative complication. Our findings suggest that female gender, Hispanic ethnicity, age at enucleation 24 months or younger, and intravenous chemotherapy prior to enucleation may increase the risk of complications.

Lateral thinking - Interocular symmetry and asymmetry in neurovascular patterning, in health and disease

No biological system or structure is likely to be perfectly symmetrical, or have identical right and left forms. This review explores the evidence for eye and visual pathway asymmetry, in health and in disease, and attempts to provide guidance for those studying the structure and function of the visual system, where recognition of symmetry or asymmetry may be essential. The principal question with regards to asymmetry is not 'are the eyes the same?', for some degree of asymmetry is pervasive, but 'when are they importantly different?'. Knowing if right and left eyes are 'importantly different' could have significant consequences for deciding whether right or left eyes are included in an analysis or for examining the association between a phenotype and ocular parameter. The presence of significant asymmetry would also have important implications for the design of normative databases of retinal and optic nerve metrics. In this review, we highlight not only the universal presence of asymmetry, but provide evidence that some elements of the visual system are inherently more asymmetric than others, pointing to the need for improved normative data to explain sources of asymmetry and their impact on determining associations with genetic, environmental or health-related factors and ultimately in clinical practice.