White-to-white corneal diameter in the Tehran Eye Study

Associations between corneal curvature and other anterior segment biometrics in young myopic adults

To investigate the associations between corneal curvature (CC) and other anterior segment biometrics in young myopic adults. In this retrospective multi-center study, 7893 young myopic adults were included. CC and other anterior segment biometrics were measured by Scheimpflug imaging (Pentacam). CC was defined as SimK at central 3 mm area, and other anterior segment biometrics included white-to-white corneal diameter (WTW), central corneal thickness (CCT), corneal volume (CV) at 3 mm, 5 mm, and 7 mm area, anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), anterior corneal eccentricity (ACE) and asphericity (ACAP), posterior corneal eccentricity (PCE) and asphericity (PCAP), anterior chamber depth (ACD), and anterior chamber volume (ACV). Univariate regression analyses were used to assess the associations between CC and other anterior segment biometrics, and multivariate regression analyses were further performed to adjusted for age, gender and spherical equivalent. CC was higher in patients of female gender and higher myopia (all P < 0.05). Eyes in higher CC quartiles had lower WTW, thinner CCT, lower CV at 3 mm and 5 mm, lower ACD, and lower ACV (all P < 0.001), but had larger ACA, larger PCA, less PCE and less PCAP (all P < 0.001), compared to eyes in lower CC quartiles. The trends of CV at 7 mm, ACE and ACAP were inconsistent in different CC quartiles. After adjusting for age, gender and spherical equivalent with multivariate linear regression, CC was positively correlated to CV at 7 mm (βs = 0.069), ACA (βs = 0.194), PCA (βs = 0.187), ACE (βs = 0.072), PCAP (βs = 0.087), and ACD (βs = 0.027) (all P < 0.05), but was negatively correlated to WTW (βs = - 0.432), CCT (βs = - 0.087), CV-3 mm (βs = - 0.066), ACAP (βs = - 0.043), PCE (βs = - 0.062), and ACV (βs = - 0.188) (all P < 0.05). CC was associated with most of the other anterior segment biometrics in young myopic adults. These associations are important for better understanding of the interactions between different anterior segment structures in young myopic patients, and are also useful for the exploration of the pathogenesis of myopia.

Eyelid Skin Grafting in Young Patients with Facial Nerve Palsy

Background: The aim of this study is to report outcomes of eyelid full-thickness skin grafting augmentation in facial nerve palsy (FNP) patients younger than 50 years of age. Methods: In a retrospective, consecutive case series, nine eyelid skin grafts performed on eight FNP patients with skin contraction (five females; median age 42 years [range, 17-47]) are presented. In most cases, upper eyelid skin grafting was combined with levator recession and anterior lamellar repositioning. Lower eyelid skin grafting was combined with lower retractors recession in all cases. Functional and cosmetic outcomes were measured preoperatively and at early (1-3 months), intermediate (3-6 months), and late (≥12 months) follow-up. Results: The corneal score improved at early follow-up (p = 0.03) and remained improved at late follow-up (p = 0.042). The gentle closure lagophthalmos was improved at late follow-up (p = 0.042). (p = 0.048). The grades of graft color, edge/skin interface, and size improved at 3-6 months post-grafting and remained improved at late follow-up (p < 0.05). Over the follow-up, four patients (50%) were recommended to have further surgical procedures. Conclusions: The preliminary results from this small cohort suggest that eyelid skin grafting is a viable option for young patients prioritizing cosmesis. This technique warrants consideration for its functional benefits.

Ocular biometrics in eyes with different white-to-white corneal diameter in young myopic adults

The interactions between white-to-white corneal diameter (WTW) and other ocular biometrics are important for planning of refractive surgery and understanding of ocular structural changes in myopia, but such interactions are rarely investigated in young myopic adults. This is a retrospective study involving 7893 young myopic adults from five centers. WTW and other ocular biometrics were measured by Pentacam. The ocular biometrics included anterior corneal curvature (AK) and posterior corneal curvature (PK), central corneal thickness (CCT) and corneal volume (CV), anterior and corneal eccentricity and asphericity, anterior corneal astigmatism (ACA) and posterior corneal astigmatism, anterior chamber depth (ACD), and anterior chamber volume (ACV). The ocular biometrics were compared among eyes of different WTW quartiles. Multivariate linear regression was used to assess the linear associations between WTW and other ocular biometrics adjusting for age, gender and spherical equivalent. In eyes of different WTW quartiles, other ocular biometrics were also significantly different (all P < 0.05). After adjusting for age, gender and spherical equivalent, WTW was positively correlated to AK (β = 0.26 to 0.29), ACA (β = 0.13), anterior corneal asphericity (β = 0.05), PK (β = 0.33 to 0.34), posterior corneal asphericity (β = 0.13), ACD (β = 0.29), and ACV (β = 40.69), and was negatively correlated to CCT (β = - 6.83), CV (β = - 0.06 to - 0.78), anterior corneal eccentricity (β = - 0.035), and posterior corneal eccentricity (β = - 0.14) (all P < 0.001). In conclusion, we found that in young myopic adults, larger WTW was associated with thinner corneal thickness, flatter corneal curvature, more anterior corneal toricity, less corneal eccentricity and asphericity, and broader anterior chamber. Our findings may fill in the gap of literature, and help us better understand how the anterior segment structures interact with the WTW in myopia.

Central anterior chamber depth correlated with white-to-white distance in normal, long, and short eyes

PURPOSE

To explore the associations between central anterior chamber depth (CACD) and other anterior segment biometric parameters and to determine the possible determinants of CACD in short, normal, and long eyes.

METHODS

The biometric data of pre-operation patients aged 50-80 years with coexisting cataract and primary angle-closure disease or senile cataract were reviewed. Axial length (AL), CACD, lens thickness (LT), central corneal thickness (CCT), and white-to-white distance (WTW) were measured by Lenstar optical biometry (Lenstar 900). The data of 100 normal eyes (AL = 22 to 26 mm), 100 short eyes (AL ≤ 22 mm), and 100 long eyes (AL ≥ 26 mm) were consecutively collected for subsequent analyses.

RESULTS

The mean age of the subjects was 66.60 ± 7.85 years, with 25.7% of the sample being men. Both CACD and WTW were found to be smallest in short eyes and were smaller in normal eyes than in long eyes (F = 126.524, P < 0.001; F = 28.458, P < 0.001). The mean LT was significantly thicker in short eyes than in normal and long eyes (4.66 mm versus 4.49 mm versus 4.40 mm; F = 18.099, P < 0.001). No significant differences were observed in CCT between the three AL groups (F = 2.135, P = 0.120). Stepwise regression analysis highlighted AL, LT, and WTW as three independent factors associated with CACD in the normal AL group. In the short AL group and long AL group, LT and WTW were independent factors associated with CACD.

CONCLUSIONS

CACD increases as AL elongates and reaches a peak when AL exceeds 26 mm. Furthermore, CACD showed inverse correlation with LT and positive correlation with WTW. A relatively small WTW results in an anteriorly positioned lens, and thus, a decrease in CACD.

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.

The Use of the Pericranial Periosteal Flap in Children for Treating Severe Lower Eyelid Retraction

PURPOSE

To describe a surgical technique that can achieve significant lower eyelid elevation in severe retraction in children using a pericranial periosteal flap with skin graft.

METHODS

A retrospective, single-center, case series of 3 consecutive pediatric cases are performed where a pericranial periosteal flap was used with a skin graft to manage severe lower eyelid retraction. Outcome measures include the extent of lower eyelid elevation (mm) and complications in the follow-up visits.

RESULTS

Three children with severe lower eyelid retraction underwent the surgery. There were 2 boys and 1 girl with the mean age of 6.7 years (range, 5-8 years). The improvement of lower eyelid retraction was 3, 3, and 7 mm at 28, 24, and 6 months, respectively. No perioperative or postoperative complications occurred.

CONCLUSIONS

Children with severe lower eyelid retraction often have a complex craniofacial and surgical history, and its surgical correction can be challenging. This case series present the successful use of pericranial flaps in treating severe lower eyelid retraction in children. The authors recommend this flap in children where traditional options have either failed or are not applicable.

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.

A deep learning framework to scale linear facial measurements to actual size using horizontal visible iris diameter: a study on an Iranian population

Digital images allow for the objective evaluation of facial appearance and abnormalities as well as treatment outcomes and stability. With the advancement of technology, manual clinical measurements can be replaced with fully automatic photographic assessments. However, obtaining millimetric measurements on photographs does not provide clinicians with their actual value due to different image magnification ratios. A deep learning tool was developed to estimate linear measurements on images with unknown magnification using the iris diameter. A framework was designed to segment the eyes' iris and calculate the horizontal visible iris diameter (HVID) in pixels. A constant value of 12.2 mm was assigned as the HVID value in all the photographs. A vertical and a horizontal distance were measured in pixels on photographs of 94 subjects and were estimated in millimeters by calculating the magnification ratio using HVID. Manual measurement of the distances was conducted on the subjects and the actual and estimated amounts were compared using Bland-Altman analysis. The obtained error was calculated as mean absolute percentage error (MAPE) of 2.9% and 4.3% in horizontal and vertical measurements. Our study shows that due to the consistent size and narrow range of HVID values, the iris diameter can be used as a reliable scale to calibrate the magnification of the images to obtain precise measurements in further research.

Investigation of ocular biometry in 4- to 9-year-old Chinese children

PURPOSE

To investigate the distribution and changes in ocular biometry in 4-to to 9-year-old Chinese children and to compare the differences between age and genders in these parameters.

METHODS

This was a school-based cross-sectional study. A total of 1,528 Chinese children, aged 4-9 years, from one primary school and 12 kindergartens, were included in the study. Axial length, corneal curvature, anterior chamber depth, and corneal diameter were measured for each child.

RESULTS

AL and anterior chamber depth gradually increased with age in both genders. No significant changes in corneal curvature or corneal diameter were detected at different ages in either genders group. The mean ALs of males and females were 22.94 ± 0.80 mm and 22.38 ± 0.79 mm, respectively. The mean corneal curvatures of males and females were 43.05 ± 1.37 D and 43.75 ± 1.48 D, respectively. The mean anterior chamber depth of males and females were 3.47 ± 0.24 mm and 3.38 ± 0.25 mm, respectively. The mean corneal diameter of males and females were 12.08 ± 0.43 mm and 11.94 ± 0.44 mm, respectively. Females had consistently shorter ALs, shorter anterior chamber depth, smaller corneal diameter, and steeper corneal curvatures than males at any age.

CONCLUSIONS

Boys had larger dimensions than girls for all ocular parameters except corneal curvature (flatter). Boys and girls showed similar trends for all parameters. Axial length and anterior chamber depth increased from 4 to 9 years of age, whereas corneal diameter and curvature did not change with age in either genders.

Refractive development I: Biometric changes during emmetropisation

PURPOSE

Although there are many reports on ocular growth, these data are often fragmented into separate parameters or for limited age ranges. This work intends to create an overview of normal eye growth (i.e., in absence of myopisation) for the period before birth until 18 years of age.

METHODS

The data for this analysis were taken from a search of six literature databases using keywords such as "[Parameter] & [age group]", with [Parameter] the ocular parameter under study and [age group] an indication of age. This yielded 34,409 references that, after screening of title, abstract and text, left 294 references with usable data. Where possible, additional parameters were calculated, such as the Bennett crystalline lens power, whole eye power and axial power.

RESULTS

There were 3422 average values for 17 parameters, calculated over a combined total of 679,398 individually measured or calculated values. The age-related change in refractive error was best fitted by a sum of four exponentials (r²  = 0.58), while all other biometric parameters could be fitted well by a sum of two exponentials and a linear term ('bi-exponential function'; r² range: 0.64-0.99). The first exponential of the bi-exponential fits typically reached 95% of its end value before 18 months, suggesting that these reached genetically pre-programmed passive growth. The second exponentials reached this point between 4 years of age for the anterior curvature and well past adulthood for most lenticular dimensions, suggesting that this part represents the active control underlying emmetropisation. The ocular components each have different growth rates, but growth rate changes occur simultaneously at first and then act independently after birth.

CONCLUSIONS

Most biometric parameters grow according to a bi-exponential pattern associated with passive and actively modulated eye growth. This may form an interesting reference to understand myopisation.

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.

Normative Values for Corneal Tomography and Comparison of Both Eyes in Young Saudi Males with 20/20 Vision Using Pentacam-HR Scheimpflug Imaging

Purpose

Anterior segment evaluation using Scheimpflug imaging with the Pentacam scanner allows the acquisition of a plethora of information. It aids in screening and diagnosing corneal pathologies and determining suitability for keratorefractive procedures. This research has significant benefits in terms of establishing normative tomographic values, which is crucial in countries where Keratoconus (KC) is more prevalent, especially among young age group, along with aiding future research in the field of refractive surgery by providing relevant normative data.

Methods

A retrospective review of digital corneal tomography images for a group of medically and ophthalmologically free males aged between 18 and 21 years with 20/20 unaided distant visual acuity was performed.

Results

A total of 1272 subjects (2544 eyes) were included. Findings revealed a mean maximal corneal curvature (Kmax) of 42.91 ± 1.40D (range 36.90–47.80D). The mean flat keratometry (K1) was 41.87 ± 1.31D (range 36.00–46.40D). The mean steep keratometry (K2) was 42.66 ± 1.35D (range 36.70–47.60D). The mean corneal astigmatism (CA) was 0.79 ± 0.37D (range 0.00D-2.30D). The mean central corneal thickness (CCT) was 558.53 ± 33.84 μm (range 421–677 μm). The mean thinnest corneal location thickness (TCLT) was 551.64 ± 34.08 μm (range 417–669μm). The mean corneal diameter (CD) and anterior chamber depth (ACD) were 12.13 ± 0.39 mm (range 10.50–13.60 mm) and 3.12 ± 0.29 mm (range 2.08–4.08 mm), respectively. The median differences between both eyes of the same subject were as follows: kmax difference of 0.20D (IQR 0.1–0.4); K1, K2 and CA difference of 0.20D (IQR 0.1–0.3) for all 3 parameters; CCT and TCLT difference of 5.00 μm (IQR 3.0–9.0) and 6.00 μm (IQR 3.0–10.0), respectively; CD difference of 0.10 mm (IQR 0.0–0.1); and ACD difference of 0.04 (IQR 0.02–0.06).

Conclusion

We believe our data can aid in establishing normative tomographic values and acceptable differences between both eyes. Our data may also help detect subtle corneal pathology and be useful for researchers and innovators in the field of ophthalmology.

Distribution of White-to-White Corneal Diameter and Anterior Chamber Depth in Chinese Myopic Patients

Purpose: To investigate the distribution of white-to-white (WTW) corneal diameter and anterior chamber depth (ACD) in Chinese myopia patients. Methods: This was a cross-sectional observational study conducted at five ophthalmic centers. Anterior segment biometry was performed in 7,893 eyes of the 7,893 myopic patients using Pentacam, and the WTW and ACD were recorded. The distribution patterns of WTW and ACD were evaluated and the correlation between WTW and ACD was analyzed statistically. Results: There were 4416 (55.95%) males and 3477 (44.05%) females. The age of the study population was 25.14 ± 5.41 years. Distribution of WTW was slightly positively skewed (Skewness = 0.0076, Kurtosis = 0.3944, KS P = 0.020) with a mean of 11.65 ± 0.38 mm and a 95% normal range of 10.91-12.39 mm. A significant difference in WTW was found among different myopia groups (P < 0.001). The ACD was normally distributed (Skewness = 0.899, Kurtosis = 0.027, KS P = 0.086). The mean ACD was 3.25 ± 0.26 mm and the 95% normal range of was 2.74-3.75 mm. A significant difference in ACD was also found among different myopia groups (P = 0.030). There was a significant correlation between WTW and ACD (r = 0.460, P < 0.001). Conclusions: In our study, 95% of the Chinese myopic patients had a WTW within 10.91-12.39 mm and an ACD within 2.74-3.75 mm. ACD and WTW were significantly different among different myopia, gender and age groups. WTW was positively correlated with ACD.

Evaluation of the White-to-White Distance in 39,986 Chinese Cataractous Eyes

Purpose

To investigate the distribution of white-to-white (WTW) distance and its associations with other biometric parameters in Chinese cataractous eyes.

Methods

Data on 39,986 eyes from 23,627 Chinese cataract patients were analyzed. Ocular biometric parameters, including WTW distance, corneal curvature, anterior chamber depth (ACD), lens thickness (LT), central corneal thickness (CCT), and axial length (AL), were obtained using the ZEISS IOLMaster 700.

Results

The mean age of patients was 63.7 ± 12.4 years, and 57.61% were female. The mean WTW distance was 11.69 ± 0.46 mm. The WTW distance was larger in male patients than in female patients for all age groups (all P < 0.001). The WTW distance was positively correlated with corneal curvature and ACD and negatively correlated with age, LT, and CCT (all P < 0.001). Multivariable analysis revealed that a larger WTW distance was associated with younger age; male gender; larger corneal curvature, ACD, and LT; and thinner CCT (all P < 0.001). Notably, the association between WTW distance and AL was not linear. As the AL increased, the WTW distance initially increased, reached a peak in the group with ALs of 24.5 to 26 mm, and then slowly decreased. However, all of the myopic eyes (AL > 24.5 mm) still had larger WTWs than the normal and short eyes (AL ≤ 24.5 mm).

Conclusions

In Chinese cataractous eyes, the WTW distance was larger in younger male patients with flatter corneas, deeper anterior chambers, thicker lenses, and thinner central corneas. The association between WTW distance and AL was not linear, and WTW distance was the largest in eyes with ALs of 24.5 to 26 mm.

Direct Brow Lift and Skin Contraction in Facial Nerve Palsy: A Switch Technique

The authors present a case series of 4 patients with facial nerve palsy who underwent a direct brow lift to correct brow ptosis, using the excised brow skin as a full-thickness skin graft to correct lower eyelid skin contracture, ectropion, and retraction. Functional outcomes were measured using the validated cornea, static asymmetry, dynamic function, synkinesis (CADS) grading system and by photographic assessment of lower eyelid height via margin reflex distance. Aesthetic outcomes were measured using a published grading scale specific to eyelid skin grafts.

Revisiting the Direct Brow Lift in Patients With Facial Palsy: 4 Key Modifications

PURPOSE

The direct brow lift is a simple and popular technique, particularly in patients with brow ptosis secondary to facial palsy. It provides a high degree of control in determining the degree of brow elevation and shape achieved. However, it is arguably the least debated in terms of addressing some of its sequelae, namely the risks of a visible or indrawn scar and forehead paraesthesia. In this article, we report outcomes using four alternative principles to those outlined in current published literature.

METHODS

All patients undergoing a primary direct brow lift for brow ptosis secondary to facial palsy between January 2015 and December 2019 under a single surgeon (R.M.) were included in the study. The technical refinements of the procedure included a W-plasty type stealth skin incision, counter-bevelling of the upper and lower incision lines, skin excision in the subcutaneous plane only with minimal excision of fat and browpexy to the frontal periosteum through small linear puncture incisions in the frontalis.

RESULTS

A total of 23 patients undergoing 24 direct brow lifts were included in the study. The mean follow-up was 1.3 years (range 0.5-3 years). No patients reported postoperative forehead paraesthesia or brow alopecia. One patient required a further temporal browlift 15 months later. Brow height was rated excellent (0-1.5 mm difference) in 71% of brows and good (1.6-4.9 mm difference) in 14% of brows. The average Manchester scar scale was 8.6/28.

CONCLUSION

The technical modifications presented substantially reduce the rates of postoperative paraesthesia, whilst achieving satisfactory aesthetic outcomes.

Recognising meibomian gland inversion in patients with facial palsy to improve the ocular surface

Background: Facial nerve palsy (FNP) is known to worsen Meibomian gland dysfunction on the affected side. Chronic Meibomian gland dysfunction leads to a variant of upper eyelid marginal entropion associated with excessive tarsal curling, termed Meibomian gland inversion (MGI). Surgical correction with grey line split, tarsoplasty and anterior lamellar repositioning (GLS surgery) appears to further improve the ocular surface in these patients who have previously undergone upper eyelid loading. Methods: Retrospective, 3 year, non-comparative, single-centre study of patients with FNP identified as having MGI and treated by GLS surgery under the supervision of a single surgeon. We present specific examination findings and a useful test (cotton tip test) to determine suitability for GLS surgery. We assessed changes in symptoms and CADS (Cornea, static Asymmetry, Dynamic function and Synkinesis) score, along with cosmetic grading of lash loss and contour and report complications. Results: 23 patients with acquired FNP underwent GLS surgery for MGI with or without lash ptosis. 17 out of the 23 patients (74%) demonstrated an improvement in their CADS score after GLS surgery. Seven patients had insufficient records with scores missing and no conclusion could be reached for this group. Improvement of corneal staining, static and dynamic symmetry were all statistically significant. No patient worsened. The cosmetic outcome including lashes, lid contour and lid margin appearance is acceptable. Whilst it is possible to achieve minimal difference between the operated and unoperated eyelids, many patients will have a small difference. Conclusion: We report outcomes of MGI treatment and useful diagnostic features.

Functional and aesthetic outcomes of eyelid skin grafting in facial nerve palsy

AIM

To report the functional and aesthetic outcomes of eyelid full-thickness skin grafting (FTSG) in patients with facial nerve palsy (FNP).

METHODS

This is a retrospective, non-comparative, single-centre review of all patients with FNP who underwent FTSG over an 8-year period. Functional outcomes were collected through case notes review: CADS (cornea, static asymmetry and dynamic and synkinesis) score facial nerve grading and lagophthalmos on blink, gentle and forced closure. Marginal reflex distance (MRD1 and MRD2) was calculated on standardised photographs. The aesthetic outcomes were assessed objectively by two blinded independent assessors who assessed standardised photographs based on a mutually agreed grading scale. Both functional and aesthetic outcomes were measured preoperatively, and at early (1-3 months), intermediate (3-6 months) and late (>9 months) postoperative periods.

RESULTS

A total of 28 eyelid FTSGs were performed on 21 patients (11 female, 10 male) between 2008 and 2016. The mean age was 68 (range, 16-89) years and the mean follow-up was 20.8 (range, 12-30) months. The CADS score (cornea (p<0.001), static asymmetry (p<0.001), dynamic function (p<0.001)), MRD2 (p=0.002) and lagophthalmos (blink (p=0.003), gentle (p<0.001), forced (p=0.003)) improved through early and late postoperative periods. Aesthetically, the grafts appeared to look natural in terms of colour, surface contour and graft edge from the intermediate postoperative period and continued to improve significantly by the late postoperative period.

CONCLUSION

The use of periocular FTSG is effective in improving lagophthalmos and periorbital symmetry in patients with FNP where skin contraction exists. They should be considered as an adjunct to other oculoplastic procedures for both functional and aesthetic rehabilitation.

Outcomes of lower eyelid retractor recession and lateral horn lysis in lower eyelid elevation for facial nerve palsy

PurposeTo report outcomes and complications of lower eyelid retractor recession and lateral horn lysis (RR) for lower eyelid elevation in patients with facial nerve palsy (FNP).Patients and methodsRetrospective review. Patients with FNP undergoing RR alone (group 1) or with adjunctive procedures (canthal suspension-group 2, tarsorrhaphy-group 3, and full-thickness skin graft-group 4) during a 5-year period were included. Patient demographics, lagophthalmos, occurrence of eyelid malpositions, recurrent retraction, and repeat procedures were noted from medical records. Measures of lower eyelid height (LEH) and lid lag on downgaze were obtained from standard photographs.ResultsForty-two patients (23 females, mean age was 59 years) were included. Mean follow-up was 24 months (range 6-77). Median improvement in LEH following surgery was significant in Group 1 (0.90 mm, IQR: 0.37-0.91, P=0.20) and in Group 2 (0.51 mm, IQR: 0.30-1.37, P<0.001), respectively. Median improvement in blink lagophthalmos was 3.00 mm (IQR: 3.00-3.50, P=0.02) in Group 1 and 3.50 mm (IQR: 1.75-5.00, P<0.001) in Group 2. Median improvement in lagophthalmos on gentle eye closure was 2.00 mm (IQR: 1.50-3.00, P=0.02) in Group 1 and 1.00 mm (IQR: 0-2.13, P=0.006) in Group 2. No new cases of ectropion were noted. 23.5% of patients required a repeat RR at a mean interval of 20 (range 1-70) months and a further 9.8% required a third procedure at a mean interval of 21 (range 18-29) months.ConclusionRR improves lower eyelid retraction and lagophthalmos in FNP either alone or when combined as an adjunctive procedure. It does not aggravate paralytic ectropion although repeated retractor recessions may be required to improve retraction.

Characterisation of the porcine eyeball as an in-vitro model for dry eye

PURPOSE

To characterise the anatomical parameters of the porcine eye for potentially using it as a laboratory model of dry eye.

METHODS

Anterior chamber depth and angle, corneal curvature, shortest and longest diameter, endothelial cell density, and pachymetry were measured in sixty freshly enucleated porcine eyeballs.

RESULTS

Corneal steepest meridian was 7.85±0.32mm, corneal flattest meridian was 8.28±0.32mm, shortest corneal diameter was 12.69±0.58mm, longest corneal diameter was 14.88±0.66mm and central corneal ultrasonic pachymetry was 1009±1μm. Anterior chamber angle was 28.83±4.16°, anterior chamber depth was 1.77±0.27mm, and central corneal thickness measured using OCT was 1248±144μm. Corneal endothelial cell density was 3250±172 cells/mm².

CONCLUSIONS

Combining different clinical techniques produced a pool of reproducible data on the porcine eye anatomy, which can be used by researchers to assess the viability of using the porcine eye as an in-vitro/ex-vivo model for dry eye. Due to the similar morphology with the human eye, porcine eyeballs may represent a useful and cost effective model to individually study important key factors in the development of dry eye, such as environmental and mechanical stresses.

Periorbital Biometric Measurements using ImageJ Software: Standardisation of Technique and Assessment Of Intra- and Interobserver Variability

Purpose:

To assess the reliability and repeatability of periorbital biometric measurements using ImageJ software and to assess if the horizontal visible iris diameter (HVID) serves as a reliable scale for facial measurements.

Methods:

This study was a prospective, single-blind, comparative study. Two clinicians performed 12 periorbital measurements on 100 standardised face photographs. Each individual’s HVID was determined by Orbscan IIz and used as a scale for measurements using ImageJ software. All measurements were repeated using the ‘average’ HVID of the study population as a measurement scale. Intraclass correlation coefficient (ICC) and Pearson product-moment coefficient were used as statistical tests to analyse the data.

Results:

The range of ICC for intra- and interobserver variability was 0.79–0.99 and 0.86–0.99, respectively. Test-retest reliability ranged from 0.66–1.0 to 0.77–0.98, respectively. When average HVID of the study population was used as scale, ICC ranged from 0.83 to 0.99, and the test-retest reliability ranged from 0.83 to 0.96 and the measurements correlated well with recordings done with individual Orbscan HVID measurements.

Conclusion:

Periorbital biometric measurements using ImageJ software are reproducible and repeatable. Average HVID of the population as measured by Orbscan is a reliable scale for facial measurements.

The distribution of orbscan indices in young population

Purpose

To determine the distribution of anterior eye biometry indices, such as keratometry pachymetry, anterior chamber depth (ACD), pupil diameter, and corneal diameter, as measured by Orbscan instrument in a young Iranian population.

Methods

A cross-sectional study was conducted, and subjects were selected through multistage cluster sampling from the students of Mashhad University of Medical Sciences. Objective and subjective refraction were performed followed by Orbscan imaging.

Results

A total of 1330 subjects were selected, 1121 of which participated in the study. After applying the exclusion criteria, the final analysis was performed on the data of 1051 subjects. The mean age of the participants was 26.1 ± 3.2 years (19–34 years old). The mean ± SD and 95% confidence interval (CI) of maximum keratometry, minimum keratometry, pupil diameter, corneal diameter, ACD, and central corneal thickness was 44.5 ± 1.7 (44.4–44.6), 43.1 ± 1.6 (43.0–43.2), 4.3 ± 0.9 (4.3–4.4), 11.7 ± 0.4 (11.7–11.7), 3.7 ± 0.3 (3.6–3.7), and 550.5 ± 35 (548.4–552.6), respectively. After adjusting for age and the mean spherical equivalent (MSE), maximum keratometry, minimum keratometry, central corneal thickness, and the thinnest pachymetry were statistically significantly higher in female subjects (P < 0.001) whilst the corneal diameter and ACD were higher in male subjects (P < 0.001). The pupil diameter and ACD showed statistically significant changes with age (P < 0.001). The MSE was only correlated with maximum keratometry and ACD (P < 0.001).

Conclusion

In this study, the distribution of Orbscan measurements for the anterior segment parameters was reported in a large sample of the young Iranian population. Age, gender, and refractive error may affect the orbscan measurements.

Occurrence and severity of upper eyelid skin contracture in facial nerve palsy

PurposeTo describe the occurrence and severity of upper eyelid skin contracture in facial nerve palsy (FNP).MethodsWe enroled consecutive patients with unilateral FNP into this study. Patients with previous upper eyelid surgery for either side were excluded. We developed a standardised technique to measure the distance between the upper eyelid margin and the lower border of brow (LMBD). FNP was graded using the Sunnybrook grading scale. Its aetiology, duration, and treatment were noted. Upper and lower marginal reflex distance and lagophthalmos were also noted.ResultsSixty-six patients (mean age 51 years) were included. FNP was owing to a variety of aetiologies. LMBD on the paralytic side was shorter than the normal contralateral side in 47 (71%), equal in 15 (23%), and larger in four (6%) patients. The mean contracture was 3.4 mm (median: 3, range: 1-12) with 11 (17%) patients showing 5 mm or more of skin contracture. The mean LMBD on the paralytic side in all patients was significantly smaller than the contralateral side; 30±3.7 (median: 30; 95% CI 29-31) compared with 32±3.7 (median: 32; 95% CI 32-33), respectively, P<0.0001, two-tailed paired t-test.ConclusionTo our knowledge, this is the first study that quantitatively demonstrates contraction of the upper eyelid skin in FNP. This finding is valuable in directing optimal early management to minimise skin contracture and to caution surgeons against unnecessary upper eyelid skin excision.

Higher order aberrations in a normal adult population

PURPOSE

To determine the distribution of Zernike coefficients and higher order aberrations in a normal population and its relationship with age, gender, biometric components, and spherical equivalent.

METHODS

During the first phase of the Shahroud cohort study, 6311 people of the 40-64-year-old population of Shahroud city were selected through random cluster sampling. A subsample of participants was examined with Zywave aberrometer (The Bausch & Lomb, Rochester, NY) to measure aberrations. Measurements of aberrations were done before cycloplegic refraction, and values generated from a minimum pupil diameter of 5 mm were reported in this analysis.

RESULTS

After applying exclusion criteria, 904 eyes of 577 people were analyzed in this study and mean age in this study was 49.5 ± 5.7 years and 62.9% were female. Mean root-mean-square (RMS) of the third-, fourth-, and fifth-order aberrations was 0.194 μm (95%CI: 0.183 to 0.204), 0.115 μm (95%CI: 0.109 to 0.121), and 0.041 μm (95%CI: 0.039 to 0.043), respectively. Total RMS coma (Z3 (-1,) Z3 (1), Z5 (-1), Z5 (1)), Total RMS trefoil (Z3 (-3,) Z3 (3), Z5 (-3), Z5 (3)), and spherical aberration (Z4 (0)) in the studied population was 0.137 μm (95% CI:0.129-0.145), 0.132 μm (95% CI: 0.123-0.140), and -0.161 μm (95%CI:-0.174 to -0.147), respectively. Mean higher-order Zernike RMS in this study was 0.306 (95% CI: 0.295-0.318) micrometer, and in the multiple model, it significantly correlated with older age and short axial length. The highest amounts of higher-order RMS were observed in hyperopes, and the smallest in emmetropes. Increased nuclear opacity was associated with a significant increase in HO RMS (p < 0.001). Analysis of Zernike coefficients demonstrated that spherical aberration (Z4 (0)) significantly correlated with nuclear cataract only (age-adjusted Coef = 0.37 and p = 0.012).

CONCLUSION

This report is the first to describe the distribution of higher-order aberrations in an Iranian population. Higher-order aberrations in this study were on average higher that those reported in previous studies.

White-to-white corneal diameter distribution in an adult population

Purpose

To determine the normal distribution of corneal diameter in a 40- to 64-year-old population and its association with other biometric components.

Methods

In a cross-sectional population-based study, subjects were selected through multistage cluster sampling from the 40- to 64-year-old citizens of Shahroud in northern Iran. After obtaining informed consents, optometry tests including refraction and visual acuity and ophthalmic exams including slit lamp exams and retinoscopy were done for all participants. Biometric components and white-to-white (WTW) corneal diameter were measured with the LENSTAR/BioGraph.

Results

Of the 6311 invitees, 5190 (82.2%) participated in the study. After applying exclusion criteria, analysis was done on data from 4787 people. Mean WTW corneal diameter in this study was 11.80 mm (confidence interval: 11.78–11.81), and based on two standard deviations from the mean, the normal range for this index was from 10.8 to 12.8 mm. WTW corneal diameter strongly correlated with corneal radius of curvature (r = 0.422) and axial length (r = 0.384). According to multiple linear regression, lower age, thinner cornea, longer AL, thicker lens, and flatter cornea were significantly related to higher WTW corneal diameter. Spherical equivalent significantly increased at higher corneal diameters (hyperopic shift).

Conclusion

The average and normal range of corneal diameter, as measured with the BioGraph, was studied in an Iranian population for the first time. The corneal diameter strongly correlates with AL and radius of curvature. WTW is larger at younger ages.

Relationship between Cornea and Lid Margin Position on the Appearance of Strabismus

PURPOSE

Previous strabismus appearance studies using images from real face photographs could not preclude the effect of other facial landmarks, such as position and contour of brow, nose, and facial outline, from pure effect of ocular deviation itself. With conceptualized drawings of eyes, we simulated strabismus deviation and collected the responses of observers.

METHODS

The experiments consisted of three sessions: (1) one-eye, (2) two-eye cornea, and (3) two-eyelid deviation simulations. On a monitor, eight different ocular deviations in increments of 6 prism diopters of horizontal or vertical deviations were simulated. Nine ophthalmology residents were asked to choose between esotropia and exotropia for horizontal simulations and hypotropia or hypertropia for vertical simulations. Psychometric function fitting was performed. Detection sensitivity, point of subjective equality, and 95% thresholds were calculated.

RESULTS

Between cornea and lid deviation simulations, there was no difference in 95% thresholds, points of subjective equality, and sensitivity (all p values > 0.10), reflecting that the relative location of cornea and lid was the determinant factor in recognizing ocular deviation. The sensitivities of vertical deviation simulations were higher than that of horizontal in two-eye cornea and lid comparisons (p values < 0.04) but not in one-eye (p value = 0.37).

CONCLUSIONS

Our results suggest that the appearance of strabismus depends not on the absolute ocular alignment but rather on the reciprocal relationship of cornea and lid margin. Vertical misalignment was more apparent than horizontal misalignment.

Ocular components during the ages of ocular development

PURPOSE

To determine the distribution of ocular biometric components and their correlation with age and sex during the ages of ocular development in a 6- to 18-year-old population in Iran.

METHOD

In this cross-sectional study, which was performed in October 2012, multi-stage stratified cluster sampling was used to sample the study population from Dezful schools, a city in the southwest of Iran. Biometric examinations were done by an experienced optometrist using the LENSTAR/BioGraph (WaveLight AG, Erlangen, Germany).

RESULTS

Among 864 selected students, 683 participated in the study (response rate: 79.1%); 377 participants (55.2%) were male, and the mean age of the participants was 12 ± 3.4 years (range: 6-18 years). The mean and 95% confidence interval of axial length (AL) were 23.13 mm (22.93-23.33), anterior chamber depth (ACD) was 3.01 mm (2.96-3.06), lens thickness (LT) was 3.58 mm (3.55-3.61), central corneal thickness (CCT) was 549.33 mic (546.59-552.07), corneal radius (CR) was 7.77 mm (7.74-7.81), corneal diameter (CD) was 12.34 mm (12.31-12.38) and pupil diameter (PD) was 4.97 (4.91-5.03). Mean AL, ACD, CD and CR were significantly higher in boys, and mean LT was significantly higher in girls. AL and ACD increased, while LT decreased significantly with age. Myopia was associated with an increase in AL and ACD, and hyperopia was associated with an increase in LT and a decrease in ACD.

CONCLUSION

This study evaluated the distribution of the biometric components of the eye during the ages of ocular development in an Iranian population. In this age range, the majority of the changes were observed in the AL and LT.

Evaluation of fungal keratitis using a newly developed computer program, Optscore, for grading digital corneal photographs

PURPOSE

To validate computer software developed to assess digital corneal photographs of fungal keratitis in clinical research.

METHODS

A cornea specialist and five medical students (after training) graded on two occasions 100 corneal photographs of patients with fungal keratitis using Optscore software. Variables assessed were lesion area, location, degree of opacity, percentage of the ulcer lying within a central 4 mm circle of the cornea. Intraclass correlation coefficients (ICCs) were used to assess intragrader reliability, agreement of the students with the corneal specialist, and the reliability of the group mean of the student raters. The area determined using Optscore was compared to the area estimated from slit lamp and to visual acuity.

RESULTS

As a group, medical students achieved an ICC greater than 0.9 for five out of the seven assessed variables. Similar levels of consistency were found after analyzing the graders' individual results compared to the specialist. The area estimated using slit lamp examination was highly correlated with the mean area determined by Optscore, as was the logarithm of the minimum angle of resolution visual acuity at enrollment.

CONCLUSIONS

Non-expert graders using Optscore to assess digital photographs of fungal keratitis are self-consistent, agree with an expert grader both as a group and individually, and measurements of ulcer area obtained from Optscore are highly correlated with measurements of the same patients obtained on clinical examination. These observations support the validity of Optscore for assessing corneal pathology associated with fungal keratitis and make it a promising clinical research tool.

Transcaruncular medial canthal tendon plication with lower eyelid suture sling in facial nerve palsy

PURPOSE

To report a technique for correcting lower eyelid punctal ectropion with an inferiorly displaced or retracted medial eyelid due to facial nerve palsy, by extending a suture sling along the pre-tarsal lower eyelid when performing transcaruncular medial canthal tendon plication.

METHODS

Single-centre retrospective, non-comparative review of patients with facial nerve palsy who underwent medial canthal tendon plication with lower eyelid suture sling (MCT suture sling). Outcome measures included: the presence of lower eyelid ectropion, medial eyelid height, punctal position, inferior marginal reflex distance (MRD) and inferior scleral show measured both pre-operatively and at the last follow-up visit.

RESULTS

Thirty-three patients with facial nerve palsy with a mean age of 59, underwent MCT suture sling for lagophthalmos and/or ectropion. Then, 66% (21/32) of cases had punctal ectropion pre-operatively and 9% (3/32) had punctal ectropion at the last follow-up. Medial eyelid height was deemed to improve in 66% (21/32) of cases at the last follow up visit. Follow-up was mean 13.5 months. Six (18%) patients were deemed failures due to inferior MRD and inferior scleral showing worse than pre-operative measurements.

DISCUSSION

We report a technique for incorporating a suture sling to transcaruncular-approach MCT plication when the medial canthus has retracted or descended thus requiring support and a posterior vector. It avoids rounding of the medial canthal angle that may occur with traditional medial canthoplasty. Transcaruncular MCT plication is well described. Incorporating a suture sling to potentially reduce single point-fixation cheese-wiring and early dehiscence is minimally invasive, non-excisional and repeatable.

White-to-white corneal diameter: normal values in healthy Iranian population obtained with the Orbscan II

AIM

To determine the normative values of white-to-white corneal diameter with Orbscan II Topography System and to compare right and left eyes data in the normal young population.

METHODS

A total of 1001 healthy participants aged 18-45y participated in this observational cross-sectional study. The study population consisted of 616 female and 385 male subjects. The corneal diameter was measured with the Orbscan II. The differences between genders, between right and left eyes and age-related changes were evaluated. Statistical analyses were performed using Student's t-test.

RESULTS

The average white-to-white distance in our study population was recorded as 11.65±0.36 mm (median: 11.60 mm, mode: 11.70 mm, minimum: 10.50 mm and maximum: 13.60 mm). The white-to-white distance was 11.60±0.35 mm in males and 11.71±0.36 mm in females which was statistically different between genders (P<0.01). However, white-to-white distance was not statistically different between right and left eyes. In addition, this parameter decreased with increasing age. Considering 95% confidence interval, corneal diameter less than 10.93 mm and greater than 12.34 mm would be considered as microcornea and megalocornea, respectively based on this study population, using the Orbscan II topography.

CONCLUSION

Detailed description and analysis of corneal diameter with Orbscan demonstrate that the obtained average value of horizontal white-to-white is higher in male than female and decreases slightly with increasing age. Our data also suggests the cut off values for definition of microcornea and megalocornea, which can be employed with this population.

Comparison of Horizontal corneal diameter measurements using the Orbscan IIz and Pentacam HR systems

PURPOSE

To compare 2 automated devices for measuring the horizontal corneal diameter [white-to-white (WTW) distance].

METHODS

In this prospective comparative case series, the WTW distance was measured by independent examiners using the Pentacam HR and the Orbscan IIz in 101 eyes of 101 healthy refractive surgery candidates. Statistical evaluation was performed using the paired t test, Pearson correlation, and the Bland-Altman method for comparison of measurement techniques.

RESULTS

The mean WTW distance measurements were 11.76 ± 0.38 mm as obtained with the Pentacam HR and 11.66 ± 0.37 mm as obtained with the Orbscan IIz (P < 0.001). The measurements were highly correlated (Pearson correlation coefficient = 0.948; P < 0.001). The 95% limits of agreement for the Pentacam HR versus the Orbscan IIz were -0.14 to 0.33 mm.

CONCLUSIONS

The observed differences in WTW distance readings between the Pentacam HR and the Orbscan IIz are not clinically relevant, and the 2 devices could be used interchangeably in clinical practice.

Incidence of lower eyelid asymmetry: an anthropometric analysis of 204 patients

BACKGROUND

To avoid complications and improve patient satisfaction with lower lid blepharoplasty, a precise assessment of any preoperative eyelid asymmetry is essential.

OBJECTIVES

The authors describe a method of assessing preoperative eyelid asymmetry through readily available software and classifying the resulting measurements.

METHODS

Digital images of 204 patients were analyzed using Photoshop CS3 Extended software (Adobe Systems, San Jose, California). The left eye was superimposed over the right eye using layers in the software program, and the lower eyelid margin and axis were outlined to obtain a diagram with the superimposed outlines of both eyes. Several measurements (ie, lateral canthal height, lower eyelid margin length and axis angle, and lower palpebral fissure surface area) were obtained for each patient. Differences between the right and left eyelids were recorded, and these data were compared between patients.

RESULTS

Of the 204 patients studied, 184 (90.2%) had some degree of asymmetry. Most (118; 64.13%) presented with the right lower eyelid at a more inferior position than the left (R-), while 66 (35.87%) presented with the right lower eyelid at a higher position than the left (R+), a difference that was highly significant (P < .001).

CONCLUSIONS

This software is a powerful and precise tool to evaluate and measure eyelid asymmetries. The use of this method showed a large degree of eyelid asymmetry preoperatively (more than 90%), which proves the importance of detecting and adequately analyzing this condition prior to surgery. The authors' simple method may be an important adjunct to obtaining optimal results in patients who seek eyelid surgery.

Endoscope-assisted vitrectomy for retinal detachment in an eye with microcornea

BACKGROUND

We report a case of an endoscope-assisted vitrectomy for the treatment of retinal detachment associated with microcornea in a normal size globe.

SUBJECTS

A 26-year-old Japanese man was referred after complaining of visual acuity loss OD. Both eyes became aphakic because of surgery for congenital cataracts in infancy. The visual acuity was 0.02 OD. The corneal diameter was 7.5 × 7.0 mm and axial length was 23.89 mm. Retinal detachment was suspected, although the details were obscure because of nystagmus and small pupils. Endoscope-assisted, 23-gauge pars plana vitrectomy and encircling buckling were performed, and reattachment of the retina was achieved.

OBSERVATIONS

Retinal breaks were identified, and peripheral parts of the retina were observed by endoscopy.

CONCLUSIONS

Endoscope-assisted vitrectomy may be advantageous for the management of detachment in an eye with microcornea.

Corneal white-to-white distance and mesopic pupil diameter

AIM

To study the relationship between corneal white-to-white (WTW) distance and mesopic pupil diameter.

METHODS

This study is composed of 30 cases that underwent photorefractive keratotomy (PRK). Pupil size measurements were performed with Schwind ORK wavefront analyzer in mesopic conditions. WTW distance was measured with a measuring caliper. Also, A-scan ultrasound examination was performed in all patients. The relationship among the mesopic pupil diameter and age, sex, axial length, lens thickness, anterior chamber depth(ACD), horizontal WTW distance, vertical WTW distance, spherical equivalent, and average keratometry were analyzed with univariate and multivariate regression analysis.

RESULTS

Mean pupil diameter was (6.39±0.80)mm (range: 3.70mm-7.73mm). Horizontal WTW distance measurements were between 11.00mm and 12.50mm and mean horizontal WTW distance was (11.79±0.43)mm. On the other hand, vertical WTW distances ranged between 10.00mm and 13.00mm, and their mean was (11.42±0.72)mm. Bivariate correlation between pupil diameter and other variables showed that the axial length, ACD, spherical equivalent, and horizontal WTW distance had a moderate correlation with mesopic pupil diameter. Multiple regression analysis revealed that spherical equivalent and horizontal WTW distances were significantly associated with mesopic pupil diameter (R=0.598, R(2)=0.358 P=0.02).

CONCLUSION

This study shows that mesopic pupil diameter is closely related to horizontal WTW distance. These two factors must be taken in consideration together in preoperative ablation zone planning.

Evaluation of myopic corneal diameter with the Orbscan II Topography System

BACKGROUND

To assess the myopic corneal diameter with Orbscan II Topography System (Bausch & Lomb, Orbtek Inc., Salt Lake City, UT, USA).

METHODS

Four hundred sixty-two eyes of 231 myopic patients and 129 emmetropic eyes were measured with the Orbscan II system. Eyes were divided into four groups according to the spherical equivalent(SE) as follows: group 1 [emmetropic group, spherical equivalents between -0.50 D and +0.50 D (-0.50<SE ≤ +0.50)]; group 2 [low myopia group, spherical equivalent between -0.50 D and -3.00D (-3.00<SE ≤ -0.50)]; group 3 [median myopia group, spherical equivalent between -3.00 and -6.00D (-6.00<SE ≤ -3.00)]; and group 4 [high myopia group, spherical equivalents of -6.00D or less (≤-6.00)]. Manifest refraction results and the Orbscan II corneal topographic maps were reviewed retrospectively. Horizontal corneal diameters (white-to-white [WTW] distance) were measured with the Orbscan II system. Subjects in different groups were matched to be comparable in terms of spherical equivalents.

RESULTS

The corneal diameter in all myopic eyes was 11.49 ± 0.36 mm. There were no significant differences between right and left eyes in the t-test for paired samples (t = -0.119, P = 0.906). Differences among four groups proved to be significant in the ANOVA (F = 4.487, P = 0.004).

CONCLUSIONS

This article provides a detailed description and analysis of Orbscan II corneal diameter of a normal myopic population. High degree of mirror image symmetry existed in myopic corneal diameter. Spherical equivalents made a difference in corneal diameter.

Outcomes of lower eyelid cicatricial entropion with grey-line split, retractor recession, lateral-horn lysis, and anterior lamella repositioning

PURPOSE

To report indications and outcomes of a technique for the correction of lower eyelid cicatricial entropion using a lower eyelid gray-line split, inferior retractor recession, lateral-horn lysis, and anterior lamella repositioning.

PATIENTS AND METHODS

Retrospective, 5-year, single-center, consecutive case series of patients with lower eyelid cicatricial margin entropion undergoing the above procedure. Patients with significant inferior fornix contraction or symblepharon undergoing concurrent fornix reconstruction with buccal mucosal grafts at the same time as lamella repositioning were excluded. Outcomes were assessed based on the review of medical case notes and clinical photographs assessed independently. Success was defined by: 1) improvement in eyelid position and 2) improvement in lower eyelid retraction.

RESULTS

Twenty-one eyelids of 19 patients (mean age 57.7 ± 22.6 years, range 5-95 years, 8 men and 11 women) were included. The mean follow up was 27.4 ± 16.8 (range 3.2-59.6) months. The causes of cicatricial entropion were as follows: ocular cicatricial pemphigoid (6), Stevens-Johnson syndrome (3), previous eyelid reconstruction (2), socket scarring (2), thermal burn (1), chemical burn (3), postradiotherapy (1), and meibomian gland dysfunction (1). A second procedure was carried out in 38% (8/21) of eyelids within 1 year. Within 3 years, 10% (2/21) and 5% (1/21) of eyelids required a third and fourth procedure, respectively. The most common lower eyelid revision procedures included anterior lamellar repositioning. Other procedures required included buccal mucous membrane grafts, everting sutures, and lateral tarsorrhaphy. Three patients with loss of >50% inferior fornix depth were included. Two had previously undergone mucosal grafts and 2 required subsequent mucosal grafts. Overall, 90% (19/21) of eyelids eventually achieved improvement in lower eyelid position following repeat surgery, including mucosal grafts in 3 eyelids. Mid-pupil lower eyelid elevation was 1 mm in 6 of 19 (32%) patients and lower eyelid lateral retraction significantly improved in 9 of 19 (47%) patients.

CONCLUSION

Based on the principles of lamella repositioning and posterior middle lamella release with formal retractor recession through a gray-line incision, this technique is of value as a lash-preserving procedure in moderate-to-severe cicatricial lower eyelid entropion, particularly where tarsoconjuctival contraction or eyelid margin distortion exists.

Composite septo-retractor recession; a surgical technique for lower-eyelid retraction and review of the literature

PURPOSE

To report the outcomes of a technique for correcting lower-eyelid retraction with composite recession of the inferior retractor and orbital septum complex, release of the lateral horn of the lower-eyelid retractors, and the orbito-malar ligament (OML) followed by skin, orbicularis, and conjunctival advancement.

METHODS

We performed a retrospective, noncomparative review of consecutive procedures performed on patients with lower-eyelid retraction undergoing composite septo-retractor recession for lower-eyelid retraction over a 4-year period, performed or supervised by a single surgeon (RM). Outcomes are based on postoperative standard photographs, including central pupil to lower-eyelid distance, inferior scleral show, and subjective improvement in lower-eyelid lateral flare.

RESULTS

We reviewed 26 eyes of 16 patients (12 men, 4 women; mean age, 61.0 ± 14.3 years). Causes of lower-eyelid retraction included involutional (n = 6), thyroid orbitopathy (n = 4), previous lower-eyelid surgery (n = 3), mechanical secondary to proptosis (n = 1), Crouzon syndrome (n = 1), and longstanding facial nerve palsy (n = 1). Mean lower-eyelid elevation achieved was 1.4 mm ± 1.3 mm (range, 0.2 to 6.6 mm; p = 0.001). Scleral show improved by 1.0 ± 0.7 mm (range, 0.0 to 2.9; p = <0.001). Preoperatively, all patients had an altered lower-eyelid contour with lateral flare, 89% cases being graded "significant." Lower-eyelid contour improved postoperatively, with only 19% graded "significant" lateral flare (p = <0.0001). No significant complications occurred, although one patient required excision of a secondary lateral canthal cyst.

CONCLUSION

Composite recession of the inferior retractor and orbital septum complex combined with release of the inferior retractor lateral horn and the OML significantly improves lower-eyelid height and contour in cases of lower-eyelid retraction and should be considered a useful option for this condition.

New insights into facial anthropometry in digital photographs using iris dependent calibration

BACKGROUND

In facial and reconstructive surgery objective assessment of anatomy is crucial to evaluate surgical results. Photographic computer-assisted anthropometry substitutes clinical measurements. The constancy of the horizontal iris diameter (IDh) allows iris dependent calibration of photographs, replacing the need for a scale.

METHODS

We performed a prospective cohort study to assess the constancy of the IDh in children. Frontal and close-up digital photographs of the eyes were taken of 100 children aged 5-18 years. The IDh was measured twice; once with a scale positioned on the forehead (IDh*(forehead)) and once with a scale positioned next to the tragus (IDh*(ear)).

RESULTS

Our data confirms the constancy of the IDh in children from the age of 5, with a mean IDh*(forehead) of 11.22 ± 0.52 mm. We found no difference between gender and no variation with age. For structures that are not in the same coronal plane as the iris, an adjusted iris diameter is needed to compensate for the difference in distance from the camera.

CONCLUSION

We confirm the reliability of iris dependent calibration in frontal photographs from the age of 5. This technique allows evaluation of a wide variety of pre-existing photographs that do not have a scale included, simplifies photographic conditions and facilitates long-term follow-up.