White-to-white corneal diameter: normal values in healthy humans obtained with the Orbscan II topography system

Alpha-1 antagonist treatment for eyelid retraction in patients with thyroid eye disease-a prospective pilot study

BACKGROUND

Sympathetic overstimulation of Müller's muscle is a suggested mechanism underlying upper eyelid retraction in thyroid eye disease (TED). We examined the effect of tamsulosin, an alpha-1 antagonist, on eyelid retraction in patients with TED.

METHODS

A single-centre prospective study. Patients with TED and associated eyelid retraction were treated with oral 0.4 mg/day tamsulosin for 3 months. Upper eyelid margins-to-reflex distance (MRD1), vertical palpebral fissure height (PFH), subjective improvement, signs and symptoms of dry eye, and lubricants use were assessed at baseline and at each subsequent visit.

RESULTS

Eleven suitable patients (mean age 47.5 ± 9.68, 8 females) enrolled in the study. Three patients discontinued the drug due to mild adverse effects (dizziness, bradycardia, nausea, and gastrointestinal distress), which resolved immediately upon stopping treatment. The other eight patients tolerated the drug well and reported no side effects. Five patients experienced an objective improvement in eyelid position and subjective improvement in eye discomfort. The mean MRD1 decreased by -1.04 ± 0.81 mm (P = 0.015), and mean PFH decreased by -1.46 ± 1.33 mm (P = 0.039). Mean duration of tamsulosin treatment was 84.63 ± 71.9 days. Patients discontinued the drug due to no improvement in MRD1 (n = 3), referral for eyelid surgery with stable inactive TED (n = 2), treatment with intravenous methylprednisolone due to worsening active TED (n = 2), and patient choice after 5 months of treatment with spontaneous resolution of symptoms (n = 1).

CONCLUSIONS

Tamsulosin is a safe potential treatment for eyelid retraction in TED and can be used as a temporary alternative therapeutic approach for patients unsuitable for surgery.

What Did the Ideal Beauty of the 15th Century Look Like? An Anthropometric Analysis of Botticelli Portraits

The aim of this study was to conduct an anthropometric analysis of the 5 portraits painted by Botticelli that depict Simonetta Vespucci. Five images in the Simonetta series by Botticelli workshop were measured. The anthropometric measurements of the face included 22 parameters on the lateral view (in 4 portraits; 18 distances and 4 angles) and 17 distances on the frontal view (in one portrait), which were measured using Adobe Photoshop. The absolute distances were calculated relative to the vertical corneal diameter (10.6 mm), which was calculated by multiplying the distance from the pupil's center to the lower margin of the iris. In the lateral faces, the nasofrontal angle (g-n-prn) was 157.6±2.4 degrees, and the nasal tip angle (n-prn-sn) was 99.7±3.4 degrees. The nasolabial angle (prn-sn-ls) was 125.7±4.9 degrees, and the labiomental angle (li-sl-pg) was 131.6±4.4 degrees. The ratio of the upper lip height to the lower lip height (sn-sto/sto-sl) was 85.4±9.0%. The ratio of the upper lip vermillion to the upper lip height (ls-sto/sn-sto) was 27.7±3.9%. The ratio of the lower lip vermillion to the lower lip height (sto-li/sto-sl) was 47.2±6.6%. Comparing the data with 21st-century Italian females, forehead II height (tr-n), physiognomical face height (tr-gn), and morphologic face height (n-gn) of the beauties of the 15th century were significantly greater than those of 21st-century Italian females. However, there were no significant differences in lower face height (sn-gn) and nose height (n-sn). Considering the ongoing cultural relevance of Renaissance art, the esthetic proportions from this study may have reflection to the present day plastic surgery.

Teprotumumab improves light sensitivity in patients with thyroid eye disease

BACKGROUND

Teprotumumab, a novel IGF-1R antibody, has been shown to significantly reduce the signs of acute and chronic Thyroid Eye Disease (TED). Light sensitivity is a reported symptom in patients with TED. There is a lack of a prospective study that has explored the effects on light sensitivity in a large cohort of patients with acute and chronic TED following treatment with teprotumumab.

METHODS

Consecutive patients who were diagnosed with TED and reported light sensitivity at baseline were considered for study eligibility. All patients had measurements of Visual Light Sensitivity Questionnaire-8 (VLSQ-8), proptosis, clinical activity score (CAS), and MRD1 (distance between the upper eyelid margin and corneal reflex, mm) and MRD2 (distance between the lower eyelid margin and corneal reflex, mm) before and after treatment.

RESULTS

Ninety patients (41 acute, 49 chronic) met the inclusion criteria. The mean (SD) age was 47.3 (14.3). Eighty-six (95.6%) patients completed all 8 infusions. There was a significant reduction in the total score and across all categories of the VLSQ-8 (p <  0.01 for all). Seventy-two (80%) patients had a clinically significant improvement (≥2 reduction) in at least one category. There was no significant difference in the total VLSQ-8 score between the acute and chronic group (p = 0.8).

CONCLUSION

Teprotumumab improves light sensitivity in patients with acute and chronic TED. The results of this study highlight that the improvements in light sensitivity following treatment are not directly related to the mechanical changes in TED, suggesting another underlying mechanism is potentially involved.

Evaluation of Long-Term Surgical and Patient-Reported Outcomes after Pediatric Facial Reanimation

BACKGROUND

Outcomes of pediatric facial reanimation beyond 10 years are not known. This cross-sectional study evaluated long-term surgical and patient-reported outcomes of adults who underwent smile reconstruction as children with either a cross-face nerve graft (CFNG) or masseter nerve transfer at least 10 years previously.

METHODS

Commissure excursion was quantified with FACE-Gram software at 3 time points: preoperatively, early postoperatively within 2 years, and at long-term follow-up. Patient-reported outcomes were evaluated with validated questionnaires (Facial Clinimetric Evaluation Scale, FACE-Q 1.0) and thematic analysis of semistructured interviews. Results are reported as median (interquartile range [IQR]).

RESULTS

A total of 42 patients were included (26 women and 16 men). Median long-term follow-up was 19.3 years (IQR, 8.8 years) for CFNG and 17.6 years (IQR, 5.8 years) for masseter nerve transfer. For both groups, commissure excursion increased significantly from preoperative to early postoperative time points and remained stable at long-term follow-up (P < 0.0001). Commissure excursion at long-term follow-up between the 2 groups was not significantly different (CFNG, 5.0 mm [IQR, 9.4 mm]; masseter nerve transfer, 8.4 mm [IQR, 4.1 mm]); P > 0.05). For patient-reported outcomes, median Facial Clinimetric Evaluation Scale score was 72 of 100, and 95% of respondents agreed with the statement "I am pleased with the result" on the FACE-Q 1.0. Overall quality of life was rated at 7 of 10 or greater by 97% of participants, and all participants would recommend the surgery to other children.

CONCLUSIONS

Pediatric facial reanimation with CFNG or masseter nerve transfer reliably improves commissure excursion with longevity beyond 10 years. Adult patients report overall high satisfaction and social functioning.

In vitro and ex vivo models of microbial keratitis: Present and future

Microbial keratitis (MK) is an infection of the cornea, caused by bacteria, fungi, parasites, or viruses. MK leads to significant morbidity, being the fifth leading cause of blindness worldwide. There is an urgent requirement to better understand pathogenesis in order to develop novel diagnostic and therapeutic approaches to improve patient outcomes. Many in vitro, ex vivo and in vivo MK models have been developed and implemented to meet this aim. Here, we present current in vitro and ex vivo MK model systems, examining their varied design, outputs, reporting standards, and strengths and limitations. Major limitations include their relative simplicity and the perceived inability to study the immune response in these MK models, an aspect widely accepted to play a significant role in MK pathogenesis. Consequently, there remains a dependence on in vivo models to study this aspect of MK. However, looking to the future, we draw from the broader field of corneal disease modelling, which utilises, for example, three-dimensional co-culture models and dynamic environments observed in bioreactors and organ-on-a-chip scenarios. These remain unexplored in MK research, but incorporation of these approaches will offer further advances in the field of MK corneal modelling, in particular with the focus of incorporation of immune components which we anticipate will better recapitulate pathogenesis and yield novel findings, therefore contributing to the enhancement of MK outcomes.

Influence of different parameters on the corneal asphericity (Q value) assessed with progress in biomedical optics and imaging - A review

The corneal eye diseases such as Keratoconus cause weakening of the cornea, with this disease the cornea can change in shape. This condition affects between 1 in 3,000 to 1 in 10,000 people. The main reason for the development of such conditions is unknown and can have significant impacts. Over the last decade, with advancements in computerized corneal topography assessments, researchers have increasingly expressed interest in corneal topography for research as well as clinical activities. Up till now, several aspheric numerical models have been developed as well as proposed to define the complex shape of the cornea. A commonly used term for characterizing the asphericity in an eye is the Q value, a common indicator of the aspherical degree of the cornea. It is one of the critical parameters in the mathematical description model of the cornea as it represents the cornea's shape and the eye's characteristics. Due to the utmost importance of this Q value of the cornea, a couple of studies have attempted to explore this parameter and its distribution, merely in terms of its influence on the human eye's optical properties. The corneal Q value is an important factor that needs to be determined to treat for any refractive errors as corneal degeneration are disease that can lead to potential problems with the structure of the cornea. This study aims to highlight the need to understand Q value of the cornea as this can essentially assist with personalising corneal refractive surgeries and implantation of intraocular lenses. Therefore, the relevance of corneal Q value must be studied in association with different patients, especially ones who have been diagnosed with cataracts, brain tumours, or even COVID-19. To address this issue, this paper first carries out a literature review on the optics of the cornea, the relevance of corneal Q value in ophthalmic practice and studies corneal degenerations and its causes. Thereafter, a detailed review of several noteworthy relevant research studies examining the Q value of the cornea is performed. To do so, an elaborate database is created, which presents a list of different research works examined in this study and provides key evidence derived from these studies. This includes listing details on the age, gender, ethnicity of the eyes assessed, the control variables, the technology used in the study, and even more. The database also delivers important findings and conclusions noted in each study assessed. Next, this paper analyses and discusses the magnitude of corneal Q value in various scenarios and the influence of different parameters on corneal Q value. To design visual optical products as well as to enhance the understanding of the optical properties of an eye, future studies could consider the database and work presented in this study as useful references. In addition, the work can be used to make informed decisions in clinical practice for designing visual optical products as well as to enhance the understanding of the optical properties of an Eye.

The Utility of Preoperative Phenylephrine Testing in Müller Muscle Conjunctival Resection Surgery for Involutional Ptosis

PURPOSE

Phenylephrine testing prior to Müller muscle conjunctival resection has traditionally been used to predict postoperative outcomes. The purpose of this study is to determine if preoperative phenylephrine testing impacts postoperative changes in eyelid position.

METHODS

In this multicenter cross-sectional cohort study, 270 eyelids of participants with involutional ptosis and levator function >12 mm who underwent Müller muscle conjunctival resection were divided into 2 comparison groups. Participants who had preoperative phenylephrine testing served as the control group and those who did not were the study group. The primary outcome measure was postoperative marginal reflex distance from the upper eyelid margin (marginal reflex distance 1 [MRD1]) at the latest follow-up visit. Secondary outcomes included change in MRD1, reoperation rate, and predictive capacity of preoperative phenylephrine testing.

RESULTS

Of the 270 eyelids that underwent Müller muscle conjunctival resection, 116 eyelids served as controls and 154 were in the study group. Mean age of participants was 62.6 years. Levator function, resection length, preoperative MRD1, change in MRD1, and latest postoperative MRD1 measures when compared in the control and study groups demonstrated no significance (p > 0.05) via 2-tailed t-test. Postoperative MRD1 was correctly predicted within 1 mm for 60.2% of eyelids that underwent preoperative phenylephrine testing.

CONCLUSIONS

Preoperative phenylephrine testing does not significantly predict postoperative eyelid elevation following Müller muscle conjunctival resection. Surgeons may thereby reassess the utility of preoperative phenylephrine testing given the lack of influence on surgical outcomes.

Use of oxymetazoline hydrochloride ophthalmic solution, 0.1% for improved lid symmetry in Graves' disease

PURPOSE

The purpose of this study is to evaluate the usage of oxymetazoline hydrochloride ophthalmic solution, 0.1% in the treatment of Graves' disease to improve lid symmetry.

METHODS

Fourteen patients were identified with unilateral upper eyelid retraction, secondary to Graves' disease. A phenylephrine test was performed to evaluate whether treating the unaffected (non-retracted) side would result in improved symmetry using Hering's law. Patients were prescribed oxymetazoline hydrochloride ophthalmic solution, 0.1% to instill into the unaffected eye. Marginal reflex distance 1 (MRD1) measurements were taken pre- and post-treatment and patient satisfaction surveys were completed.

RESULTS

The average pre-treatment MRD1 difference between the right eye (OD) and the left eye (OS) was 2.46 [range 1.50-4.00]. The average post-treatment MRD1 difference between OD and OS was 0.39 [range 0.00-1.00]. One hundred percent of patients were satisfied or very satisfied with the improvement in symmetry.

CONCLUSIONS

Oxymetazoline hydrochloride ophthalmic solution, 0.1% is a potential method to improve symmetry in patients with Graves' disease and unilateral upper eyelid retraction via Hering's law, especially for non-surgical candidates or those who prefer non-surgical treatment. Our results indicate improved MRD1 differences between fellow eyes and patient satisfaction regarding the symmetry of the upper eyelids.

The argument for two-handed cataract surgery in veterinary ophthalmology

Despite access to contemporary phacoemulsification technology and the strong shift to two-handed nucleofractis techniques in human medicine, a one-handed, single incision approach has persisted among Diplomates of the American College of Veterinary Ophthalmologists. The perpetuation of techniques such as bowl-sculpting one-handed phacoemulsification in veterinary medicine is multifactorial; it is likely associated with the lack of two-handed training in residency programs, the challenges of learning on complex cases, the ease of teaching one-handed versus two-handed techniques to a resident, and the lack of specific instrumentation available designed for larger lens size, among other factors. Additionally, variation in globe and palpebral fissure size in veterinary patients complicates the training of cataract surgery. Finally, many mentors or mentors' mentors, were trained alongside previous generations of MD surgeons who performed bowl sculpting techniques during the transition from extracapsular cataract extraction to phacoemulsification, and understandably, are not comfortable teaching a two-handed technique consistently. The authors have observed an unwillingness to convert from one-handed to two-handed technique in the post-residency career for most veterinary ophthalmologists; this could be due to the high expectations becoming a specialist, especially when the stakes are as high as in phacoemulsification. Therefore, the authors advocate for hands-on training in multiple nucleofractis techniques, including two-handed methods during residency training. Simply put, if residents are not trained and comfortable with two-handed techniques by the end of residency, they are less likely to make further changes later in their career. In this article, we aim to explore the proposed rates of one-handed versus two-handed mentors currently teaching veterinary phacoemulsification, the history of cataract surgery, and to discuss the benefits of two-handed nucleofractis techniques. The authors will also illustrate and provide videos as well as some tools for veterinary ophthalmologists wishing to learn two-handed techniques.

Hemorrhage Following Muller's Muscle Conjunctival Resection: Description and Case-Control Study

PURPOSE

The purpose of this study was to report a series of patients with postoperative hemorrhage after Muller's muscle conjunctival resection surgery and compare risk factors and outcomes with a control population.

METHODS

In this case-control study, records of patients who underwent Muller's muscle conjunctival resection over 5 years were reviewed for a history of postoperative hemorrhage occurring >24 hours after surgery. A 4:1 control population was matched for age and sex. Clinical data collected included demographics, medical history, medications, and subsequent surgery. Preoperative and 3-month postoperative marginal reflex distance 1 were measured digitally using ImageJ. The hemorrhage and control groups were compared using Fisher's exact tests for categorical variables and independent samples t tests for continuous variables.

RESULTS

The hemorrhage group contained 10 patients (mean age 66.4 ± 18.5 years). The control group consisted of 40 age and sex-matched controls. Of 350 charts reviewed, there were 10 cases of postoperative hemorrhage (incidence 2.9%). Hemorrhage occurred a mean of 4.2 ± 1.3 (range 2-7) days after surgery and lasted for a mean of 29.3 ± 19.1 (range 12-72) hours. In all 10 cases, the bleeding resolved with conservative measures. There was no difference between the hemorrhage and control groups in terms of medical conditions, blood thinners, and surgical revision. Preoperative, postoperative, and change in marginal reflex distance 1 did not differ between the hemorrhage and control groups.

CONCLUSIONS

Hemorrhage occurs approximately 4-5 days postoperatively in a small percentage of patients undergoing Muller's muscle conjunctival resection surgery. This investigation did not identify any consistent risk factors, and outcomes in this patient population appear no different than controls.

Hypoglobus, Exophthalmos, and Interpupillary Distance: Measuring Globe Dystopia in Thyroid Eye Disease

PURPOSE

Thyroid eye disease (TED) is characterized by a variety of disfiguring periocular changes. Vertical globe changes affecting the relative position of the eyelids are not well understood in patients with TED. This study seeks to determine the effect of orbital decompression on vertical globe displacement in patients with TED, without TED, and with intraconal tumor (ICT).

METHODS

For this cross-sectional study, a clinical database was used to identify patients with TED. Comparison groups were drawn from separate anonymized databases. Vertical position and interpupillary distance (IPD) were measured from photographs and exophthalmos was measured via Hertel's exophthalmometer. Primary outcomes were vertical globe position at baseline and postoperatively in patients with TED and ICT. Secondary outcomes included the relationship between vertical globe position, exophthalmos, and IPD.

RESULTS

Among 269 participants meeting the inclusion criteria, mean vertical globe position was significantly lower in patients with TED following lateral decompression surgery compared to controls, after accounting for race, age, and sex. While patients with ICT had a significant difference in preoperative and postoperative IPD, patients with TED did not. Medial or inferior decompression did not significantly change globe position and lateral decompression did not cause lateral canthal dystopia in patients with TED. No association between postoperative changes in exophthalmometry, IPD, and globe position was found in patients with TED.

CONCLUSIONS

Patients with TED experience hypoglobus that does not improve following decompression surgery. There was no correlation between change in vertical globe position and exophthalmos or IPD among patients with TED. Surgeons should discuss the possibility of hypoglobus as a persistent finding for patients with TED undergoing decompression surgery.

Deciphering the etiology of undiagnosed ocular anomalies along with systemic alterations in pediatric patients through whole exome sequencing

Inherited and developmental eye diseases are quite diverse and numerous, and determining their genetic cause is challenging due to their high allelic and locus heterogeneity. New molecular approaches, such as whole exome sequencing (WES), have proven to be powerful molecular tools for addressing these cases. The present study used WES to identify the genetic etiology in ten unrelated Mexican pediatric patients with complex ocular anomalies and other systemic alterations of unknown etiology. The WES approach allowed us to identify five clinically relevant variants in the GZF1, NFIX, TRRAP, FGFR2 and PAX2 genes associated with Larsen, Malan, developmental delay with or without dysmorphic facies and autism, LADD1 and papillorenal syndromes. Mutations located in GZF1 and NFIX were classified as pathogenic, those in TRRAP and FGFR2 were classified as likely pathogenic variants, and those in PAX2 were classified as variants of unknown significance. Protein modeling of the two missense FGFR2 p.(Arg210Gln) and PAX2 p.(Met3Thr) variants showed that these changes could induce potential structural alterations in important functional regions of the proteins. Notably, four out of the five variants were not previously reported, except for the TRRAP gene. Consequently, WES enabled the identification of the genetic cause in 40% of the cases reported. All the syndromes reported herein are very rare, with phenotypes that may overlap with other genetic entities.

Design and Evaluation of an Eye Mountable AutoDALK Robot for Deep Anterior Lamellar Keratoplasty

Partial-thickness corneal transplants using a deep anterior lamellar keratoplasty (DALK) approach has demonstrated better patient outcomes than a full-thickness cornea transplant. However, despite better clinical outcomes from the DALK procedure, adoption of the technique has been limited because the accurate insertion of the needle into the deep stroma remains technically challenging. In this work, we present a novel hands-free eye mountable robot for automatic needle placement in the cornea, AutoDALK, that has the potential to simplify this critical step in the DALK procedure. The system integrates dual light-weight linear piezo motors, an OCT A-scan distance sensor, and a vacuum trephine-inspired design to enable the safe, consistent, and controllable insertion of a needle into the cornea for the pneumodissection of the anterior cornea from the deep posterior cornea and Descemet's membrane. AutoDALK was designed with feedback from expert corneal surgeons and performance was evaluated by finite element analysis simulation, benchtop testing, and ex vivo experiments to demonstrate the feasibility of the system for clinical applications. The mean open-loop positional deviation was 9.39 µm, while the system repeatability and accuracy were 39.48 µm and 43.18 µm, respectively. The maximum combined thrust of the system was found to be 1.72 N, which exceeds the clinical penetration force of the cornea. In a head-to-head ex vivo comparison against an expert surgeon using a freehand approach, AutoDALK achieved more consistent needle depth, which resulted in fewer perforations of Descemet's membrane and significantly deeper pneumodissection of the stromal tissue. The results of this study indicate that robotic needle insertion has the potential to simplify the most challenging task of the DALK procedure, enable more consistent surgical outcomes for patients, and standardize partial-thickness corneal transplants as the gold standard of care if demonstrated to be more safe and more effective than penetrating keratoplasty.

Management of Ocular Surface Inflammation with Persistent Epithelial Defects Using a Sutureless Human Amniotic Membrane Dehydrated Matrix: A Prospective Study Utilizing a Digital Ocular Surface Assessment Tool

Purpose

To report the outcomes of using a sutureless human amniotic membrane dehydrated matrix (HAMDM) in the management of a range of ocular surface conditions utilizing a digital ocular surface disease assessment tool.

Methods

Two UK NHS Trusts - Queen Victoria Hospital Foundation Trust (East Grinstead and Maidstone) and Tunbridge Wells Trust (Kent) - prospectively treated patients with ocular surface disease with sutureless HAMDM. The patient cohort was assessed for resolution of epithelial defects, ocular surface inflammation, and best-corrected visual acuity pre- and posttreatment. Measurements of ocular surface inflammation and epithelial defect size were assessed using AOS digital imaging software, a validated tool for objective grading of bulbar conjunctival redness and measurement of corneal epithelial defects.

Results

A total of 47 applications of sutureless HAMDM on 46 eyes of 46 patients (25 male, 21 female, age 9-94 years) were assessed across various etiologies for an average of 24.0±14.1 days. Patients with limbal stem-cell deficiency (n=17), persistent epithelial defects (n=16), neurotrophic corneal disease (n=7), filamentary keratitis (n=2), corneal erosion (n=1), corneal thinning (n=1), ocular surface inflammation (n=1), and traumatic corneal laceration (n=1) were included in the study. Across all patents, 63% of eyes showed complete healing of epithelial defects and 32.6% of eyes showed partial resolution. The average rate of healing (wound closure) was 0.36 mm2 per day across the overall patient cohort, and the rate of healing in cases with complete resolution of epithelial defects was 0.41 mm2 per day. Inflammation across all four quadrants of the ocular surface remained stable. Visual acuity across the patient cohort remained stable (61%) and improved in 26% of patients (0.06±0.51 logMAR).

Conclusion

Sutureless HAMDM application can be accomplished in just a few minutes and effectively treat a range of ocular surface disease in a clinical, nonsurgical setting. The AOS imaging software offered a quantitative methodology for measuring epithelial defect size and inflammation state.

Design and Biocompatibility of a Novel, Flexible Artificial Cornea

Purpose

We sought to introduce the materials, design, and biocompatibility of a flexible and suturable artificial corneal device.

Methods

Single-piece, fully synthetic, optic-skirt design devices were made from compact perfluoroalkoxy alkane. The skirt and the optic wall surfaces were lined with a porous tissue ingrowth material using expanded polytetrafluoroethylene. Full-thickness macroapertures around the skirt perimeter were placed to facilitate nutrition of the recipient cornea. Material properties including the skirt's modulus of elasticity and bending stiffness, optic light transmission, wetting behavior, topical drug penetrance, and degradation profile were evaluated.

Results

The final prototype suitable for human use has a transparent optic with a diameter of 4.60 mm anteriorly, 4.28 mm posteriorly, and a skirt outer diameter of 6.8 mm. The biomechanical and optical properties of the device closely align with the native human cornea with an average normalized device skirt-bending stiffness of 4.7 kPa·mm4 and light transmission in the visible spectrum ranging between 92% and 96%. No optical damage was seen in the 36 devices tested in fouling experiments. No significant difference was observed in topical drug penetrance into the anterior chamber of the device implanted eye compared with the naïve rabbit eye.

Conclusions

The flexibility and biocompatibility of our artificial cornea device may offer enhanced tissue integration and decreased inflammation, leading to improved retention compared with rigid keratoprosthesis designs.

Translational Relevance

We have developed a fully synthetic, flexible, suturable, optic-skirt design prototype artificial cornea that is ready to be tested in early human feasibility studies.

Corneal Characteristics of Myopic Malay School Children and Their Association with Axial Length

Introduction

Corneal characteristics are unique to each eye and can vary among different levels of refractive errors. However, minimal data are available in the literature on corneal characteristics in myopic Malay school children including the difference between the low myopic group and the moderate myopic group. Therefore, this study aims to determine the corneal characteristics of myopic Malay school children and their associations with axial length.

Methods

A total of eighty-four data samples were extracted from forty-two myopic Malay school children. Measurements of the central corneal thickness (CCT), corneal curvature, corneal diameter, and axial length were measured using Lenstar LS900, a non-contact optical biometer. Data were later stratified by the spherical equivalent refraction (SER) into a low myopic group and a moderate myopic group, and paired t-test were employed to determine the differences in the corneal characteristics between these two groups. Univariate and multivariate linear regressions were performed to identify factors that are significantly associated with axial length.

Results

There was no significant difference in the CCT, corneal curvature and corneal diameter between the low myopic group and the moderate myopic group (t82=0.015, P=0.99), (t82=-0.802, P=0.43) and (t82=-0.575, P=0.57), respectively. Pearson univariate correlation analysis found that axial length significantly correlated with corneal curvature (r=-0.765, P<0.001) and corneal diameter (r=0.614, P<0.001) but no significant correlation found with CCT (r=0.046, P=0.68). Multiple regression analysis showed that axial length was significantly associated with a flatter corneal curvature (P<0.001), older age (P<0.001) and larger corneal diameter (P=0.02).

Conclusion

This study reported the corneal characteristics in myopic Malay school children and its associations with axial length. Results of this study can serve as a reference value for the myopic Malay schoolchild population.

Efficacy of Emergency Penetrating Keratoplasty with Cryopreserved Human Donor Corneas

INTRODUCTION

To investigate the long-term outcomes of emergency penetrating keratoplasty using cryopreserved human donor corneas in the management of actual or imminent corneal perforation.

METHODS

A retrospective analysis was performed of the treatment efficacy of emergency penetrating keratoplasty using a cryopreserved human donor cornea, in 14 eyes of 14 patients with corneal ulcers of different etiology. For comparison, the medical histories of 14 patients who had undergone penetrating keratoplasty with the same indication, but received a regularly processed human corneal graft, were retrospectively analyzed. In both groups, the primary endpoint for graft failure was repeat surgery, defined as the necessity for amniotic membrane transplantation, conjunctival flap, or repeat penetrating keratoplasty, during a follow-up time of maximally 12 months.

RESULTS

The difference in the need for repeated surgeries between the cryopreserved human donor cornea group and cultivated tissue graft group was not statistically significant (p = 0.835). Specifically, repeat complex surgery of any kind within 6 months was necessary in 50% of the cryopreserved cornea group and in 57.1% of the control group, with no further surgical interventions during the remainder of the follow-up period. However, repeat penetrating keratoplasty occurred more frequently in the cryopreserved cornea group (n = 5) than in the control group (n = 1) during the first 12 months after treatment (p = 0.048).

CONCLUSION

Cryopreserved corneas appear to be a viable option for promptly addressing emergencies and stabilizing the corneal situation, providing a faster solution compared to waiting for fresh tissue availability. However, repeat penetrating keratoplasty is more frequent when cryopreserved human donor corneas are used. Cryopreserved human donor corneas may be useful if surgical treatment is urgent and alternative options, such as tissue use, a conjunctival flap, or multilayer amniotic membrane transplantation, are not available.

Normative data of corneal diameter and palpebral fissure height in a large cohort of South Indian children

The purpose of this study was to establish the normative data of horizontal visible iris diameter (HVID), vertical visible iris diameter (VVID), and palpebral fissure height (PFH) in a cohort of South Indian children. The study included 1,234 children from six schools of different regions of Tamil Nadu state, India. HVID, VVID, and PFH were measured using a simple millimeter ruler by three optometrists. Based on their age, the children were divided into three groups: preprimary school children (4-5 years), primary school children (6-10 years), and high school children (11-15 years). Mean age was 4.49 ± 0.50 years, 8.00 ± 1.41 years, and 12.87 ± 1.42 years in the three groups, respectively. Mean HVID was 10.45 mm, 10.54 mm, and 10.73 mm, respectively. Mean VVID was 9.18 mm, 9.32 mm, and 9.57 mm, respectively. Similarly, mean PFH was 8.15 mm, 8.30 mm, and 8.52 mm, respectively. There was a significant difference in HVID, VVID, and PFH among the three age groups (P ≤ 0.001), as well as among male and female children in the 6-10 years age group (P ≤ 0.05) but not in the other groups. Intraclass correlation coefficient values (0.78-0.95) show good agreement among the three optometrists for all parameters. The normal range of HVID, VVID, and PFH presented in the current study can help practitioners in the diagnosis of corneal disorders, serve as a basis for the design of contact lenses, and enable accurate intraocular lens power calculations for South Indian children.

Analysis of Sexual Dimorphic Features of the Jawline and Chin in White Celebrity Faces

BACKGROUND

The jawline greatly influences facial shape and contributes to facial dimorphism. Analysis of lower facial shape and sexual dimorphic differences in contemporary attractive white faces can advance the goals of lower facial aesthetics and facial gender-affirming surgery (FGAS).

METHODS

Full-face, front-view photos of 47 white female and 21 white male celebrities were included from a list generated using GQ magazine's Highest Paid Models issue, People Magazine's Beautiful issue (1991-2022), and celebrities featured on lifestyle websites. Facial landmarks were detected through a facial analysis program using Vision framework and MATLAB. After converting pixel distances to absolute distances, lower face measurements were compared between males and females.

RESULTS

The mean lower facial height was 6.08 cm in females and 7.00 cm in males ( P value<0.001). The mean bigonial width was 11.21 cm in females and 12.30 cm in males ( P value<0.001). The ratio of facial height to lower facial height was 2.98 in females and 2.76 in males ( P value<0.001), signifying that symmetry in facial thirds is more prevalent in attractive female faces, while a longer lower face is more common in attractive male faces. The greatest differences in female and male facial contours were at gonial angles and chin.

CONCLUSIONS

Analysis of contemporary white celebrity faces demonstrated significantly wider and longer lower facial measurements in males. The overall contour of the female lower face was more tapered at the gonial angles and chin compared to males. These results are important when planning lower facial rejuvenation or FGAS, as lower face size and proportions influence perceived gender and attractiveness.

An integrated model of the human cornea as a linear biaxial birefringent medium

A novel model of human corneal birefringence is presented. The cornea is treated as a homogeneous biaxial linear birefringent medium in which the values of the binormal axes angle and organization of the main refractive indices vary continuously from the apex to the limbus. In its central part, the angle between binormal axes is 35°, and para centrally, it smoothly increases to 83.7°. The values of the main refractive indices (nx, ny, nz) change, as well as their order, from nx < nz < ny to nz < nx < ny. The transition between these two states was described with a normal distribution (μ = 0.45, σ = 0.1). The presented model corresponds with the experimental results presented in the literature. To our knowledge, it is the first model that presents the anisotropic properties' distributions of the entire cornea. The presented model facilitates a better understanding of the corneal birefringence phenomenon directly related to its lamellar structure.

Kinematics of the Upper Eyelid and the Globe During Downward Excursion With Comparative Analysis in Patients With Thyroid Eye Disease

PURPOSE

To analyze the kinematics of the upper eyelid and the globe on downward excursion for potential use in monitoring thyroid eye disease (TED) progression in an objective manner.

METHODS

Ten normal volunteers and 10 patients with TED were studied. A high-speed (240 fps) digital camera with a coaxial light source set at a constant distance from the subjects' eyes was used to record the excursion of the upper eyelid and the globe from extreme upgaze to extreme downgaze. Clinical data, including age, gender, race, thyroid function tests, Vision, Inflammation/Congestion, Strabismus/motility restriction, Appearance/exposure score (primary surgeons' preference of TED grading system), exophthalmometry, and eyelid measurements were collected for all patients with TED. Frame-by-frame analyses of the videos were performed using Python software (version 3.6) and the Open Source Computer Vision Library. Temporal resolution was obtained by measuring the number of frames from initiation of eyelid and globe movement from extreme upgaze (t 0 ) to extreme downgaze (t f ). Spatial resolution was obtained by measuring the number of pixels the eyelid margin and the globe traversed from t 0 to t f . The data were then plotted on a graph to calculate the velocity of the upper eyelid and the globe during downward excursion.

RESULTS

Velocimetric calculations using high-speed photography suggests that downward excursion of the upper eyelid, and the globe occurs in 2 phases: the acceleration phase and the deceleration phase. Comparative analysis of slow-motion videography demonstrates that patients with TED were found to have attenuation in the early acceleration phase of upper eyelid excursion compared with normal subjects. In patients with TED, the difference in velocity between the eyelid and the globe occurs in the early deceleration phase.

CONCLUSIONS

The upper eyelid normally synchronizes intimately with the globe during downward eye movement. Data from this study reveal that attenuation mostly in the early deceleration phase of eyelid movement relative to the globe accounts for the dynamic eyelid lag seen on clinical examination. Further analysis is needed to show if a quantified von Graefe sign can be used as an objective means of monitoring progression in TED.

An Adjustable Magnetic Levator Prosthesis for Customizable Eyelid Reanimation in Severe Blepharoptosis II: Randomized Evaluation of Angular Translation

Purpose

Examine the effect of force modulation via angular translation of a static magnetic field for customizable treatment of severe blepharoptosis.

Methods

Prototype adjustable-force magnetic levator prostheses (aMLP) consisted of a spectacle-mounted magnet in rotatable housing and small eyelid-attached magnets embedded in a biocompatible polymer. Interpalpebral fissure (IPF) of 17 participants with severe blepharoptosis was continuously measured for one minute at five spectacle magnet angles, with order randomized and participant and data analyst masked. The hypothesis that angular position affected opening IPF (o-IPF), minimum blink IPF (m-IPF), and comfort ratings (1-10) was tested.

Results

The aMLP improved o-IPF from 4.5 mm without the device to 6.2 mm on the lowest force setting (P < 0.001) and 7.1 mm on the highest setting (P < 0.001) and allowed for complete volitional blink regardless of setting (average m-IPF 0.4 mm and no change with aMLP; P = 0.76). Spontaneous blink without the device (2.0 mm) was affected on the highest force setting (m-IPF 3.9 mm; P < 0.001) but only marginally so on the lowest setting (3.0 mm; P = 0.06). Comfort (7.6/10) did not vary with the angle (P > 0.36). Profile analysis found substantial individual responses to angle (P < 0.001), confirming the value of customization.

Conclusions

Angular translation provided adjustable force, which had a statistically and clinically meaningful impact on eye opening and the completeness of the spontaneous blink. This quantitative evidence supports continued use of the angular translation mechanism for force adjustment in the customizable magnetic correction of severe blepharoptosis.

Translational Relevance

Evidence for the benefit of customizable magnetic force via angular translation in a larger sample of participants than reported previously.

The Cosine Law to Choose the Correct Forceps Shaft Length for Macular Surgery in Highly Myopic Eyes

PURPOSE

To demonstrate a mathematical analogy between the Pythagorean theorem using the axial a-scan measurement, i.e., the distance between the central cornea and the sclerotomy, and the lengths of the forceps in eyes of patients with all axial lengths.

METHODS

We used the Pythagorean equation (c 2 = a 2 + b 2 ) to calculate the adequate shaft length of the forceps to use in macular surgery, especially in highly myopic eyes, where c 2 represents the axial length (hypotenuse); b 2 the sum of the corneal ray and distance between the corneal limbus and the sclerotomy (base side); and a 2 the distance between the sclerotomy and the fovea (perpendicular side).

RESULTS

We reproduced the cosine law to estimate the distance between the sclerotomy and the fovea. The distance between the sclerotomy and the foveal area is shorter than the axial length and can become smaller based on the distance from the sclerotomy to the corneal limbus.

CONCLUSION

This simple mathematical formula is useful when performing surgery in highly myopic eyes, in which there can be difficulties reaching the macular area.

Animal Models for the Study of Keratoconus

Keratoconus (KC) is characterized by localized, central thinning and cone-like protrusion of the cornea. Its precise etiology remains undetermined, although both genetic and environmental factors are known to contribute to disease susceptibility. Due to KC's complex nature, there is currently no ideal animal model to represent both the corneal phenotype and underlying pathophysiology. Attempts to establish a KC model have involved mice, rats, and rabbits, with some additional novel animals suggested. Genetic animal models have only been attempted in mice. Similarly, spontaneously occurring animal models for KC have only been discovered in mice. Models generated using chemical or environmental treatments have been attempted in mice, rats, and rabbits. Among several methods used to induce KC in animals, ultraviolet radiation exposure and treatment with collagenase are some of the most prevalent. There is a clear need for an experimental model animal to elucidate the underlying mechanisms behind the development and progression of keratoconus. An appropriate animal model could also aid in the development of treatments to slow or arrest the disorder.

Anterior Segment Biometry in a Caucasian Population with Cataracts

PURPOSE

To investigate biometric factors of the anterior segment of phakic eyes with cataracts.

METHODS

This population-based study included Caucasian patients with cataracts in the University Eye Hospital, Goethe University Frankfurt, Germany. Biometric parameters were measured using the swept-source optical coherence tomography method. Patients were grouped into intermediate stages based on decades of life.

RESULTS

In total, 6289 eyes of 3615 patients (age: 70.67 ± 8.42 years) were included. Age-related reductions in the anterior chamber depth (mean ± standard deviation) decreased from 3.26 ± 0.42 mm (group A: 55-59 years) to 2.94 ± 0.4 mm (group G: 85-89 years), and those in the axial length decreased from 24.37 ± 1.87 mm (group A) to 23.39 ± 1.07 mm (group G). Likewise, the white-to-white distance decreased from 12.12 ± 0.48 mm (group A) to 11.96 ± 0.47 mm (group G). Lens thickness tended to increase accordingly from 4.39 ± 0.36 µm (group A) to 4.9 ± 0.40 µm (group G). A comparison of the eyes showed no detectable lateral difference regarding the biometric parameters between the groups (axial length: p = 0.26, Rosenthal effect size = 0.03; lens thickness: p = 0.12, R = 0.03; anterior chamber depth: p = 0.63, Rosenthal effect size = 0.01). The axial length and anterior chamber depth differed significantly between sexes (r = 0.22, p < 0.0001 and r = 0.16, p < 0.0001, respectively). Multiple regression analysis of the anterior chamber depth as a function of biometry parameters as well as age and sex additionally indicated a positive correlation of anterior chamber depth with white-to-white distance (b = 0.32, p = 10-5), axial length (b = 0.10, p = 10-5), keratometry (b = 0.07, p = 10-5), and lens thickness (b=-0.05, p = 10-5) with a high effect size (Cohen f2=1.866, p = 10-5) and strong multiple correlation coefficient (Rosenthal effect size = 0.80, p = 10-5).

CONCLUSIONS

In the anterior segment, there are age- and sex-dependent changes in biometric parameters. In addition, changes in anterior chamber depth were noted in relation to white-to-white distance, axial length, keratometry, and lens thickness. These data should be considered in lens calculation formulas.

Posterior corneoscleral limbus: Architecture, stem cells, and clinical implications

The limbus is a transition from the cornea to conjunctiva and sclera. In human eyes, this thin strip has a rich variation of tissue structures and composition, typifying a change from scleral irregularity and opacity to corneal regularity and transparency; a variation from richly vascularized conjunctiva and sclera to avascular cornea; the neural passage and drainage of aqueous humor. The limbal stroma is enriched with circular fibres running parallel to the corneal circumference, giving its unique role in absorbing small pressure changes to maintain corneal curvature and refractivity. It contains specific niches housing different types of stem cells for the corneal epithelium, stromal keratocytes, corneal endothelium, and trabecular meshwork. This truly reflects the important roles of the limbus in ocular physiology, and the limbal functionality is crucial for corneal health and the entire visual system. Since the anterior limbus containing epithelial structures and limbal epithelial stem cells has been extensively reviewed, this article is focused on the posterior limbus. We have discussed the structural organization and cellular components of the region beneath the limbal epithelium, the characteristics of stem cell types: namely corneal stromal stem cells, endothelial progenitors and trabecular meshwork stem cells, and recent advances leading to the emergence of potential cell therapy options to replenish their respective mature cell types and to correct defects causing corneal abnormalities. We have reviewed different clinical disorders associated with defects of the posterior limbus and summarized the available preclinical and clinical evidence about the developing topic of cell-based therapy for corneal disorders.

Comparison of INTREPID® balanced and hybrid tips on anterior capsule rupture in ex vivo porcine eyes

Phacoemulsification has emerged as the global standard for cataract surgery, and various novel methods, tools, and agents have promoted surgical efficiency and reduced complications. Conventionally, the phaco tip, which cleaves and aspirates the cataractous lens, has been mainly constructed of metal. In this study, the risk of anterior capsule rupture was evaluated under conditions of different power modes, longitudinal (Mode-L), torsional (Mode-T), or both (Mode-LT), and different aspiration powers (0 or 200 mmHg), using a traditional metal phaco tip (Group-M) or a new phaco tip with a high-strength polymer overmold on the needle edge (Group-P), which was developed to reduce the risk of capsule rupture. One hundred twenty porcine eyes were used for experiments within a setting of typical human physiological intraocular pressure. We found that Group-M showed capsule rupture with a smaller ultrasound power than did Group-P, regardless of power mode or aspiration power. In Group-M, there was no significant difference in risk of capsule rupture among power modes, however in Group-P, capsule rupture was least likely to occur with Mode-T. These results provide useful information for inexperienced ophthalmologists to improve surgical safety.

Facial Morphometrics in Black Celebrities: Contemporary Facial Analysis Using an Artificial Intelligence Platform

The diversity of patients pursuing facial aesthetic and facial gender-affirming surgery (FGAS) is increasing, yet there is a paucity of objective guidelines to facilitate surgical decision-making in patients of color. We conducted a quantitative analysis of black celebrities using standardized frontal photos of 21 female and 21 male celebrities. Celebrities were chosen from popular entertainment magazines and websites, including People Magazine, the Internet Movie Database (IMDb), Cosmopolitan, and Essence. For each celebrity, 100 facial landmarks were detected through a facial analysis artificial intelligence (AI) program. Black males had greater facial height, bizygomatic width, lower facial height, and bigonial width than females. However, the facial height to bigonial width ratio was similar between genders and approximated the golden ratio (1.618). Female faces demonstrated a greater mid-face height to total facial height proportion, and males had a greater lower facial height proportion. Females exhibited an upward-slanted medial brow and shorter total eyebrow length, nose height, and alar width. Forehead height above the lateral brow was greater in males, while central forehead height was similar to females. This is the first study that has utilized AI to provide ethnicity-specific facial morphometrics relevant to facial rejuvenation and FGAS in the black population.

Analysis of Hairline and Forehead Sexual Dimorphic Aesthetics in 60 Celebrities Using Artificial Intelligence

Upper facial third morphometrics are an important consideration in aesthetic facial surgery and facial gender-affirming surgery. Although there are generally accepted sexual dimorphic differences, an in-depth analysis of forehead morphometrics in attractive individuals is lacking.

Methods

Thirty white female and 30 white male celebrities were included. Three full-face front-view photographs of each celebrity were evaluated by a facial analysis program, using Vision framework and MATLAB. After converting pixel distances to absolute distances, midline and lateral forehead heights were calculated and compared between men and women.

Results

Forehead height was similar between attractive men and women, but forehead width was shorter in women. Analysis of forehead height at various points along the hairline demonstrated that forehead measurements above the lateral brow and brow peak were significantly greater in men. Mean forehead height above the lateral eyebrow was 3.51 cm in women and 4.16 cm in men (P = 0.017). Forehead height above the eyebrow peak was 4.34 cm in women and 5.55 cm in men (P < 0.001). Medial forehead height was similar between men and women, indicating that the greatest difference in attractive male and female foreheads is in the lateral forehead and forehead width.

Conclusions

Analysis of attractive white celebrities demonstrated no significant differences in central forehead heights between men and women. Forehead width and lateral forehead height were significantly smaller in women, with an overall downward slanting contour. Male hairlines were more horizontal and slanting upward laterally. These results have implications in facial rejuvenation and facial gender-affirming surgery.

Using Artificial Intelligence to Quantify Sexual Dimorphism in Aesthetic Faces: Analysis of 100 Facial Points in 42 Caucasian Celebrities

Background

Sexual dimorphism has been studied in the faces of average populations and worldwide celebrities; however, a focused analysis of attractive Caucasian faces has not been conducted.

Objective

The study harnesses the power of artificial intelligence (AI) to efficiently analyze these facial patterns in attractive Caucasian male and female celebrities.

Methods

Twenty-one male and 21 female Caucasian celebrities were selected based on popular editorial rankings, modeling agencies, and casting directors from 2017 to 2022. Frontal photographs of celebrities aged 23 to 42 without facial animation were selected. One hundred facial landmarks were identified using semi-automatic image analysis software consisting of modified Apple Vision (Cupertino, CA) machine-learning algorithms with additional custom landmarks. Measurements were converted to absolute distances by fixing subjects' white-to-white corneal diameters to the validated average in Caucasians.

Results

Attractive females had significantly greater upper and middle facial proportions, more uniformly divided facial thirds, and greater canthal tilt compared with males. Attractive males had significantly greater facial height, bizygomatic and bigonial widths, medial and total brow lengths, and alar width than females. The golden ratio (1.618) was observed in the ratio of facial height to bigonial width in females (1.613), and attractive males closely approximated that ratio (1.566). There were no significant differences in interpupillary distances, eyebrow angles, or horizontal palpebral fissure lengths. No faces in either sex exhibited scleral show.

Conclusions

The study is the first to utilize AI in quantifying key sexual dimorphisms among Caucasian celebrity faces. Identifying these contemporary patterns may provide valuable considerations in planning facial aesthetic and gender affirmation surgery.

Level of Evidence 3

Coexistence of MRCS syndrome, extremely long axis and exfoliation syndrome: a case report and literature review

BACKGROUND

The coexistence of MRCS (microcornea, retinal dystrophy, cataract, and posterior staphyloma) syndrome and extremely long axis is rare since microcornea frequently accompanies with diminution of entire anterior segment and occasionally the whole globe. In the case presented here, combination of these two elements were identified, together with XFS (exfoliation syndrome).

CASE PRESENTATION

A 66-year-old Han Chinese woman presented for consultation due to impaired vision which accompanied throughout her entire life span and worsened during the last 2 years. Combination of MRCS syndrome and extremely long axial length was evidently diagnosed in both eyes, with XFS confirmed in her right eye, but mutation screening failed to identify disease-causing sequence variants in some specific genes reported previously, including BEST1 and ARL2. However, likely pathogenic mutations in FBN2 gene were identified. Bilateral cataract phacoemulsification without intraocular lens implantation was performed using scleral tunnel incision and under general anesthesia. At 3-month follow-up, ocular recovery of the patient was satisfactory.

CONCLUSIONS

The case presented here exhibited rare coexistence of MRCS syndrome, extremely long axis and XFS. The complexity of her ocular abnormalities brought challenges to surgical management, in which multidisciplinary collaboration is often required. Furthermore, the genetic analysis in this case yielded a possible novel candidate gene for MRCS syndrome and provided evidence in support of genetic heterogeneity in this phenotype.

Comparison of the effectiveness and safety of the "endoscope-assisted polypropylene mesh lift" and "gliding brow lift" techniques for the treatment of lateral brow ptosis

BACKGROUND

There are many techniques used to treat lateral brow ptosis. This study compared two techniques that are used for lateral brow rejuvenation in terms of effectiveness and safety-namely, endoscope-assisted polypropylene mesh lift (EAML) and gliding brow lift (GBL).

METHOD

Eighty-six patients who underwent brow lift surgery between March 2018 and June 2020 were included in this retrospective study. Forty-four patients were operated on using the EAML technique, whereas 42 patients were operated on using the GBL technique. The measurement of defined distances in photographs was carried out using a software, and the Brow Positioning Grading Scale (BPGS) and Global Aesthetic Improvement Scale (GAIS) were applied in the pre and postoperative periods.

RESULTS

The measurement results obtained in the postoperative period were better than those obtained in the preoperative period for both the techniques, whereas the results obtained at postoperative month 3 were found to be better than those obtained at month 12 (p < 0.05). The results were similar between the measurements at postoperative months 3 and 12 for both the techniques. The loss of brow height from postoperative months 3-12 was greater in the GBL group (p < 0.05). The postoperative scores on the BPGS were found to be better in both techniques than the preoperative scores (p < 0.05). The GAIS score at postoperative month 12 was found to be better in the EAML group. The two groups had similar rates of complications.

CONCLUSION

The two techniques were found to have similar effectiveness and safety profiles for brow rejuvenation.

LEVEL OF EVIDENCE: 4

Efficacy of Müller's Muscle-conjunctival Resection With or Without Suturing for the Correction of Ptosis

PURPOSE

The purpose of this study was to compare the efficacy of Müller muscle-conjunctival resection (MMCR) with or without suturing for the correction of ptosis.

METHODS

A retrospective chart review was performed of 30 patients (56 eyelids) undergoing sutureless (sMMCR) (34 eyelids) or conventional MMCR (cMMCR) (22 eyelids). Primary outcome measures were the change in MRD1 and vertical eyelid height (VLH). Secondary outcome measures were the amount of resection of MMCR (rMMCR) and postoperative symmetry of 1 mm or less.

RESULTS

In total, 49 eyelids (87.5%) had involutional ptosis and 7 (12.5%) had contactlens induced ptosis. The age and follow up between the sMMCR and cMMCR groups was, respectively, 65.1 ± 11.0 versus 65.5 ± 11.0 years and 4.0 ± 2.5 versus 6.5 ± 2.1 months. Preoperatively there were no significant differences noted between the sMMCR and cMMCR groups. Postoperatively there was a statistically significant difference in change of MRD1 between the sMMCR and cMMCR groups, 2.74 ± 0.20 mm and 2.02 ± 0.25 mm ( p = 0.026). The difference in change of VLH and rMMCR was not significant between the sMMCR and cMMCR groups, 2.28 ± 0.13 mm and 2.14 ± 0.15 mm ( p = 0.49) and 9.29 ± 2.14 versus 9.46 ± 1.97 mm ( p = 0.83). There were no significant differences in postoperative symmetry.

CONCLUSION

The sMMCR and cMMCR techniques demonstrated equal effectiveness for the correction of ptosis. The rapid sMMCR could become the procedure of choice for the correction of involutional and contact lens induced ptosis.

In vivo corneal elastography: A topical review of challenges and opportunities

Clinical measurement of corneal biomechanics can aid in the early diagnosis, progression tracking, and treatment evaluation of ocular diseases. Over the past two decades, interdisciplinary collaborations between investigators in optical engineering, analytical biomechanical modeling, and clinical research has expanded our knowledge of corneal biomechanics. These advances have led to innovations in testing methods (ex vivo, and recently, in vivo) across multiple spatial and strain scales. However, in vivo measurement of corneal biomechanics remains a long-standing challenge and is currently an active area of research. Here, we review the existing and emerging approaches for in vivo corneal biomechanics evaluation, which include corneal applanation methods, such as ocular response analyzer (ORA) and corneal visualization Scheimpflug technology (Corvis ST), Brillouin microscopy, and elastography methods, and the emerging field of optical coherence elastography (OCE). We describe the fundamental concepts, analytical methods, and current clinical status for each of these methods. Finally, we discuss open questions for the current state of in vivo biomechanics assessment techniques and requirements for wider use that will further broaden our understanding of corneal biomechanics for the detection and management of ocular diseases, and improve the safety and efficacy of future clinical practice.

Typical localised element-specific finite element anterior eye model

Purpose

The study presents an averaged anterior eye geometry model combined with a localised material model that is straightforward, appropriate and amenable for implementation in finite element (FE) modelling.

Methods

Both right and left eye profile data of 118 subjects (63 females and 55 males) aged 22-67 years (38.5 ± 7.6) were used to build an averaged geometry model. Parametric representation of the averaged geometry model was achieved through two polynomials dividing the eye into three smoothly connected volumes. This study utilised the collagen microstructure x-ray data of 6 ex-vivo healthy human eyes, 3 right eyes and 3 left eyes in pairs from 3 donors, 1 male and 2 females aged between 60 and 80 years, to build a localised element-specific material model for the eye.

Results

Fitting the cornea and the posterior sclera sections to a 5th-order Zernike polynomial resulted in 21 coefficients. The averaged anterior eye geometry model recorded a limbus tangent angle of 37° at a radius of 6.6 mm from the corneal apex. In terms of material models, the difference between the stresses generated in the inflation simulation up to 15 mmHg in the ring-segmented material model and localised element-specific material model were significantly different (p < 0.001) with the ring-segmented material model recording average Von-Mises stress 0.0168 ± 0.0046 MPa and the localised element-specific material model recording average Von-Mises stress 0.0144 ± 0.0025 MPa.

Conclusions

The study illustrates an averaged geometry model of the anterior human eye that is easy to generate through two parametric equations. This model is combined with a localised material model that can be used either parametrically through a Zernike fitted polynomial or non-parametrically as a function of the azimuth angle and the elevation angle of the eye globe. Both averaged geometry and localised material models were built in a way that makes them easy to implement in FE analysis without additional computation cost compared to the limbal discontinuity so-called idealised eye geometry model or ring-segmented material model.

Nano-based eye drop: Topical and noninvasive therapy for ocular diseases

Eye drops are the most accessible therapy for ocular diseases, while inevitably suffering from their lower bioavailability which highly restricts the treatment efficacy. The introduction of nanotechnology has attracted considerable interest as it has advantages over conventional ones such as prolonged ocular surface retention time and enhanced ocular barrier penetrating properties, and achieving higher bioavailability and improved treatment efficacy. This review describes various ocular diseases treated with eye drops as well as the physiological and anatomical ocular barriers faced with through drug administration. It also summarizes the recent advances regarding the utilization of nanotechnology in developing eye drops, and how to optimize the nanocarrier-based ocular drug delivery systems. The prospective future research directions for nano-based eye drops are also discussed here.

Change in lacrimal gland volume and aqueous tear production following treatment with teprotumumab

BACKGROUND

Dry eye syndrome occurs in up to 85% of patients with thyroid eye disease (TED). Lacrimal gland enlargement correlates with subjective tearing and a reduction in quality of life in patients with TED.

METHODS

In this prospective longitudinal study, patients presenting for the treatment of TED were considered for eligible. Primary outcomes included a change in the volume of the lacrimal gland and the production of tears following treatment with teprotumumab. The volume of lacrimal glands and proptosis was calculated using 3D volumetric analysis. Tear production was measured by Schirmer's test and associated symptoms were assessed using the VLSQ-8. The orbit with the most proptosis was designated the study orbit and the contralateral orbit was designated the fellow orbit.

RESULTS

Twenty patients were included. Mean (SD) age was 61 (18) and mean duration of TED prior to therapy was 48 months (47). Lacrimal gland volume in the study orbit decreased from 768 mm³ (288) to 486 mm³ (173) (p < 0.01) following therapy. For the fellow orbit, volume reduced from 637 mm³ (261) to 379 mm³ (147) (p < 0.01). Schirmer's test reading (STR) in the study orbit increased from 14.5 mm (8.2) to 23 mm (10) (p < 0.01) (59%) following treatment. In the fellow orbit, STR increased from 12.7 mm (7) to 21 mm (9) post therapy (69%) (p < 0.01). There was a significant improvement on all parts of the VLSQ-8.

CONCLUSION

Teprotumumab significantly reduces TED related expansion of the lacrimal gland, increases tear production, and improves dry eye symptoms.

Effects of Upper Blepharoplasty Techniques on Headaches, Eyebrow Position, and Electromyographic Outcomes: A Randomized Controlled Trial

The aim of this study was to assess changes in headaches, eyebrow height, and electromyographic (EMG) outcomes of the frontalis and orbicularis oculi muscles, after an upper blepharoplasty with or without resecting a strip of orbicularis oculi muscle. In a randomized controlled trial, 54 patients received an upper blepharoplasty involving either only removing skin (group A) or removing skin with an additional strip of orbicularis muscle (group B). Preoperative, and 6 and 12 months postoperative headache complaints were assessed using the HIT-6 scores and eyebrow heights were measured on standardised photographs. Surface EMG measurements, i.e., electrical activity and muscle fatigue, were assessed for the frontalis and orbicularis oculi muscles preoperatively and 2, 6, and 12 months postoperatively. Significantly fewer headaches were reported following a blepharoplasty. The eyebrow height had decreased, but did not differ between groups. Regarding the surface EMG measurements, only group A's frontalis muscle electrical activity had decreased significantly during maximal contraction 12 months after surgery (80 vs. 39 mV, p = 0.026). Fatigue of both the frontalis and the orbicularis oculi muscles did not change significantly postoperatively compared to baseline. EMG differences between groups were minor and clinically insignificant. The eyebrow height decreased and patients reported less headaches after upper blepharoplasty irrespective of the used technique.

Traditional versus Laterally Extended Upper Blepharoplasty Skin Excisions: Objective and Patient-Reported Outcomes

BACKGROUND

Different skin excision shapes may result in different aesthetic outcomes after upper blepharoplasty.

METHODS

Two skin-only excision shapes were evaluated objectively and subjectively in 28 matched patients with laterally extended skin excision (group A) or traditional elliptical skin excision (group B). The pretarsal show, lateral eyebrow height, amount of scarring (evaluated with the Patient and Observer Scar Assessment Scale), and patient-reported aesthetic results (evaluated using FACE-Q) were scored and compared at 6 and 12 months postoperatively.

RESULTS

In both groups, pretarsal show improved significantly after blepharoplasty. The homogeneity of pretarsal show improved significantly in the lateral extension group (group A) together with slightly more pretarsal show (0.5 to 0.8 mm at central pupil region) at 6 and 12 months of follow-up compared with group B ( P = 0.004). A trend was observed in the exocanthion 45-degree measurement, in which group A had 0.6 mm greater pretarsal show 6 months postoperatively. Homogeneity of the pretarsal show had improved significantly in group A, but not in group B, at 12 months after blepharoplasty. No other significant differences were observed between the groups regarding pretarsal show measurements or FACE-Q scores. Both groups showed descent of the lateral eyebrow, but this was only significant in group B. Group B showed 1.4 to 2.0 mm more descent compared with group A. Scarring and adverse effects scores were low in both groups and did not differ.

CONCLUSION

Laterally extended skin excision and traditional elliptical skin excision both result in positive aesthetic results, but the laterally extended skin excision technique is accompanied by a slightly more favorable outcome.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Bézier curves as a total approach to measure the upper lid contour: redefining clinical outcomes in palpebral surgery

AIMS

To define and quantify the upper lid contour by adapting Bézier curves with a newly developed software in normal subjects, assessing their reliability.

METHODS

Fifty eyes of 50 healthy patients with no ocular pathology were included in this study from October 2020 to November 2020. All measurements were performed on Bézier curves adjusted to the upper lid contour. An original software was used to measure the radial and vertical midpupil-to-lid margin distances (MPLD), temporal-to-nasal (T/N) ratios, contour peak location and grade of superposition (GS) and asymmetry (GA) indexes. We calculated differences in the variables measured regarding age, gender or the side of the eye being assessed.

RESULTS

The mean Bézier curve showed an excellent level of inter-rater reliability (intraclass correlation coefficient of 0.99). The median GS index of each eyelid to the mean Bézier curve was 95.4%, 8.5 IQR, and the median GA index was 3%, 3.4 IQR. The mean contour peak location was -0.35 mm, SD 0.45. Overall, the mean central MPLD was 4.1 mm, SD 0.6. No significant differences were found between male and female patients in variables derived from Bézier curves.

CONCLUSION

Bézier curves may become a very useful tool for the assessment of upper lid contour, contour peak and symmetry. GS and GA indexes, along with the T/N area ratio are potential outcomes for this purpose. All current variables can be obtained just from one single Bézier curve measurement. Our results offer an in-depth exhaustive description of these variables and their distribution in the normal population.

Objective Outcomes of Trichophytic Brow Lift and Hairline Advancement in Facial Feminization Surgery

Importance: The upper facial third is an important area to address in facial feminization surgery (FFS). Objective: This study seeks to quantify the changes in eyebrow, hairline, and forehead heights associated with brow lift and hairline advancement surgery in the transgender patient population. Design, Setting, and Participants: A cohort study performed at an academic medical center. Main Outcomes and Measures: Pre- and postoperative frontal view photographs underwent computer-aided photograph analysis. Brow position, hairline position, and forehead height were measured. Patient self-identified race, ethnicity, as well as other demographic factors were also collected. Results: Forty-six patients underwent FFS with brow lift and hairline advancement with photographs permitting measurement. Eyebrow analysis was performed in 33 patients. Hairline and forehead analyses were accomplished in 30 patients. The mean brow elevation was 4.6 mm across all locations. The forehead reduction achieved was 9.8-11.3 mm. Conclusion and Relevance: Trichophytic brow lifting with hairline advancement outcomes was able to be reliably quantified from standardized clinical photographs. On average, 4-5 mm of brow lift, 6-7 mm of hairline lowering, and 10-11 mm of forehead reduction were achieved, contributing to a more feminine appearance of the upper facial third.

Comparative Analysis of Central Corneal Thickness in Four Fish Models

To understand the left-right asymmetry of vertebrate eyes, this study measured the central corneal thickness (CCT) of Oryzias curvinotus, Oryzias melastigma, Oryzias latipes, and zebrafish with optical coherence tomography. The results showed that the CCTs were significant differences among different species and groups, even between the right and left eyes of each fish. The values of the CCTs (mean ± SD, μm) for the four species were 104.71 ± 14.49, 61.88 ± 8.63, 64.76 ± 10.36 and 56.96 ± 10.48, respectively. Moreover, comparing the two wild groups of O. curvinotus from Sanya on N18° and Gaoqiao on N21°, the CCT value for the low-latitude group was 104.71 ± 14.49 μm, greater than the high latitude group 76.13 ± 5.70 μm significantly (t-test, p = 0.0001). Lastly, the paired Student's t-test revealed that significant CCT differences existed between the left and right eye for all four species and groups, of which zebrafish and O. melastigma were belonging to the left thicker type in contrast to the others. This study laid a foundation for understanding the causes of the difference in CCT, and also provided possible fish models for human researches on keratomileusis, glaucoma, and other corneal diseases.

Profile of biological characterizations and clinical application of corneal stem/progenitor cells

Corneal stem/progenitor cells are typical adult stem/progenitor cells. The human cornea covers the front of the eyeball, which protects the eye from the outside environment while allowing vision. The location and function demand the cornea to maintain its transparency and to continuously renew its epithelial surface by replacing injured or aged cells through a rapid turnover process in which corneal stem/progenitor cells play an important role. Corneal stem/progenitor cells include mainly corneal epithelial stem cells, corneal endothelial cell progenitors and corneal stromal stem cells. Since the discovery of corneal epithelial stem cells (also known as limbal stem cells) in 1971, an increasing number of markers for corneal stem/progenitor cells have been proposed, but there is no consensus regarding the definitive markers for them. Therefore, the identification, isolation and cultivation of these cells remain challenging without a unified approach. In this review, we systematically introduce the profile of biological characterizations, such as anatomy, characteristics, isolation, cultivation and molecular markers, and clinical applications of the three categories of corneal stem/progenitor cells.

Daily Variations of Corneal White-to-White Diameter Measured with Different Methods

PURPOSE

A precise determination of the corneal diameter is essential for the diagnosis of various ocular diseases, cataract and refractive surgery as well as for the selection and fitting of contact lenses. The aim of this study was to investigate the agreement between two automatic and one manual method for corneal diameter determination and to evaluate possible diurnal variations in corneal diameter.

PATIENTS AND METHODS

Horizontal white-to-white corneal diameter of 20 volunteers was measured at three different fixed times of a day with three methods: Scheimpflug method (Pentacam HR, Oculus), placido based topography (Keratograph 5M, Oculus) and manual method using an image analysis software at a slitlamp (BQ900, Haag-Streit).

RESULTS

The two-factorial analysis of variance could not show a significant effect of the different instruments (p = 0.117), the different time points (p = 0.506) and the interaction between instrument and time point (p = 0.182). Very good repeatability (intraclass correlation coefficient ICC, quartile coefficient of dispersion QCD) was found for all three devices. However, manual slitlamp measurements showed a higher QCD than the automatic measurements with the Keratograph 5M and the Pentacam HR at all measurement times.

CONCLUSION

The manual and automated methods used in the study to determine corneal diameter showed good agreement and repeatability. No significant diurnal variations of corneal diameter were observed during the period of time studied.

Corneal Biometric Parameters and Refractive Properties in Microcornea With Normal Axial Length

PURPOSE

The purpose of this study was to evaluate the features of and relationships among corneal diameter, central corneal thickness (CCT), endothelial cell density (ECD), and corneal refractive properties in cases of microcornea (MC) with normal axial length.

METHODS

We included 22 patients (35 eyes) with MC and cataracts and 41 patients (48 eyes) with isolated cataracts as age-matched controls. They were divided into patients with MC younger than 18 years (MC-child), patients with MC 18 years or older (MC-adult), children with congenital cataracts (CCs), and adults with senile cataracts (SCs). Corneal diameter, axial and anterior chamber length, and keratometry were measured; central corneal endothelial cell imaging was performed.

RESULTS

The mean horizontal corneal diameter was 7.71 ± 1.51 and 8.78 ± 0.52 mm in MC-child and MC-adult groups, respectively, and 11.89 ± 0.59 and 11.52 ± 2.42 mm in child and adult controls, respectively. The mean CCT was 641.26 ± 63.37 (MC-child) and 617.38 ± 45.40 mm (MC-adult), and 554.92 ± 34.64 (CC) and 551.58 ± 28.47 mm (SC). The mean ECD was 2898.47 ± 443.90 (MC-child) and 2825.81 ± 484.65 cells/mm 2 (MC-adult), and 3155.13 ± 372.67 (CC) and 2749.33 ± 399.63 cells/mm 2 (SC). The average keratometry was 44.22 ± 3.14 D (MC-child) and 43.86 ± 2.59 D (MC-adult), and 44.19 ± 1.44 D (CC) and 43.94 ± 1.34 D (SC).

CONCLUSIONS

Patients with MC and normal axial length possess specific parameters, including significantly smaller corneal diameter and thicker CCT than the patients in the control groups. There were no significant differences in ECD and average keratometry. These parameters should be taken into account in the follow-up and treatment.

Safety and anterior chamber structure of evolution implantable Collamer lens implantation with short white-to-white corneal diameters

Introduction

To evaluate the safety and anterior chamber structure of implantation of the Evolution (EVO) implantable Collamer lens (EVO-ICL) in patients with short white-to-white (WTW) corneal diameters.

Materials and methods

The study population was divided into two groups: the experimental group (34 eyes of 34 patients) with WTW corneal diameters of ≤10.6 mm and the control group (59 eyes of 59 patients) with WTW corneal diameters of >10.6 mm. The outcome measures included uncorrected distance visual acuity, corrected distance visual acuity, refractive power, intraocular pressure (IOP), anterior chamber angle, depth, volume, and vault.

Results

The safety indices of the experimental and control groups were 1.17 ± 0.30 and 1.12 ± 0.14, respectively (P > 0.05); the effectiveness indices were 1.16 ± 0.31 and 1.07 ± 0.17, respectively (P > 0.05). The simulation curves of the expected and actual corrections in the experimental and control groups were y = 0.9876x – 0.0927 and y = 0.9799x + 0.0343, respectively. There were no significant differences between the IOPs and anterior chamber structures of the two groups (P > 0.05). The average vaults of the experimental and control groups were 395.76 ± 155.32 and 389.49 ± 135.01 μm, respectively (P > 0.05).

Conclusion

EVO-ICL implantation in patients with short WTW corneal diameters (≤ 10.6 mm) was determined to be a safe, effective, and predictable method for correcting myopia. The changes in the anterior chamber structure were still within normal limits after the surgery, the IOP remained stable, and the ideal vault was achieved after the surgery.

Corneal endothelial cell density and its correlation with birth weight, anthropometric parameters, and ocular biometric parameters in Chinese school children

Background

To describe the distribution of corneal endothelial cell density (ECD), and to explore its correlation with birth weight (BW), anthropometric parameters, and ocular biometric parameters in Chinese school children.

Methods

In the population-based cross-sectional Nanjing Eye Study, children were measured for anthropometric information, for ECD by the noncontact specular microscope and for ocular biometric parameters by the optic low-coherent reflectometer. Data from right eyes were analyzed to illustrate the distribution of ECD and for determining correlated factors with ECD using univariate and multiple linear regression analysis. Comparisons among three different BW groups were performed using a one-way ANOVA analysis followed by the Bonferroni correction for pairwise comparisons.

Results

Of 1171 children, the mean (± standard deviation) ECD was 2875.34 ± 195.00 cells/mm². In the Multiple Linear Regression analysis, BW, gender and central corneal thickness were significantly associated with ECD. The ECD increased by 36.16 cells/mm² with BW increasing by 1 kg (P = 0.001) and increased by 0.44 cells/mm² for every additional 1 mm in central corneal thickness (P = 0.01). The ECD of girls was 54.41 cells/mm² higher than boys (P < 0.001). Children born with low BW presented significantly lower ECD than those born with normal BW (P < 0.05) and high BW (P < 0.05). Age and axial length were not significantly associated with ECD (P = 0.06 and P = 0.21, respectively).

Conclusions

In Chinese school children aged 82 to 94 months, the ECD is positively correlated with BW and central corneal thickness, in which BW is a newly identified associated factor. It is like that gender plays an important role in ECD distribution while girls have relatively greater ECD than boys.