Vertical Corneal Diameter Research Articles

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 (10.6mm), 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.

Comparison of angle-to-angle distance and corneal diameter in pediatric eyes using ultrasound biomicroscopy.

To investigate the relationship between corneal diameter and internal corneal span determined from angle-to-angle distance using ultrasound biomicroscopy (UBM) in an observational cross-sectional patient population comprised of 54 eyes (28 healthy control eyes, ages 0.1 to 11.3 years; 26 eyes with primary congenital glaucoma, ages 0.1 to 3.5 years) from 41 pediatric participants ages 0.1 to 11.3 years (mean age: 3±3 years, median age: 2 years). Forty cornea photographs with reference ruler and 110 UBM images were obtained. Three observers measured horizontal and vertical corneal diameter and angle-to-angle distance in each cornea photo and UBM image using ImageJ and the average values were used. Main outcome measures were Pearson correlation coefficient, linear regression, mean difference between corneal diameter and angle-to-angle distance, and intra-class correlation coefficients among measurements from all three observers for each parameter. Corneal diameter and angle-to-angle distance had a strong positive correlation horizontally (Pearson r = 0.89, p<0.001) and vertically (r = 0.93, p<0.001). Correlation was consistent regardless of presence of primary congenital glaucoma and participant age. Regression analysis demonstrated a linear relationship between the parameters for horizontal (CD = 0.99*AA+0.28, R2 = 0.81, p<0.001) and vertical (CD = 0.91 *AA+1.32, R2 = 0.85, p<0.001) dimensions. Overall, reliability was good-excellent, ranging from an ICC of 0.76 for vertical corneal diameter to 0.90 for horizontal angle-to-angle distance. Based on the strong positive correlation found between corneal diameter and angle-to-angle distance in our study population, UBM image analysis can be used to accurately estimate corneal diameter from angle-to-angle distance in children with healthy eyes and primary congenital glaucoma. UBM may provide a useful intraocular alternative for estimating corneal diameter and monitoring diseases that affect the cornea in infants and children, such as congenital glaucoma.

Predictors of Femtosecond Laser–Assisted Arcuate Keratotomy Efficacy for Astigmatism Correction in Cataract Surgery

To evaluate the predictors related to the efficacy of epithelium- and Bowman membrane-penetrating femtosecond laser-assisted arcuate keratotomy (FSAK) in the treatment of preoperative astigmatism in patients with cataracts and to clarify the predictive role of the incision-to-limbus distance. This retrospective study included patients who underwent femtosecond laser-assisted cataract surgery combined with FSAK using the LenSX platform (Alcon Laboratories, Inc) at Beijing Aier-Intech Eye Hospital from March 2017 to December 2021. The Lenstar LS900 (Haag-Streit, Inc) was used to measure the horizontal corneal diameter, and ImageJ software (National Institutes of Health) was used to measure the vertical corneal diameter and incision-to-limbus distance. Finally, the measured values were converted. Changes in corneal astigmatism before and 3 months after surgery were analyzed using Alpins vector analysis. Correlation analysis and regression analysis were used to evaluate the factors associated with surgically induced astigmatism (SIA) in preoperative ocular biometric parameters. The study included 94 eyes of 94 patients. The mean target induced astigmatism was 1.36 ± 0.44 diopters (D), SIA was 0.82 ± 0.43 D, and mean difference vector was 0.70 ± 0.40 D. Pearson correlation analysis and univariate regression analysis showed that preoperative corneal astigmatism, arcuate keratotomy arc length, incision-to-limbus distance, and astigmatism type were significant predictors of SIA. Multiple variable regression analysis included parameters such as age, arcuate keratotomy arc length, and incision-to-limbus distance and established a multiple regression model of SIA (all P < .01). The incision-to-limbus distance was a significant independent predictor of SIA, and inclusion of this parameter may further improve the accuracy of the nomogram. [J Refract Surg. 2022;38(8):480-486.].

Ocular biometric measurements and central corneal thickness in African pediatric population

AIM: To determine the ocular biometric measurements and central corneal thickness (CCT) in Nigerian children so as to have a reference database. METHODS: A hospital-based observational study of a cross-section of children seen consecutively between November 2017 and January 2018. The socio-demographic data of patients, visual acuity (VA) was assessed with LogMAR charts and Lea charts according to age group. Examination under anesthesia (EUA) was carried out for children eight years and below. Anterior and posterior segments examination through dilated pupil were done. Corneal diameters (CD) were assessed using calipers. Intraocular pressures (IOP) were examined using handheld tonometer, CCT and axial length (AL) were measured using the ultrasonic pachymeter. Cycloplegic refraction was carried out after clinical examination. Data were entered into and analysed using SPSS version 17 to generate results through descriptive statistics. Frequencies and cross tabulations of variables were done (P&lt;0.05). RESULTS: Sixty-six children with 132 eyes of ages between 3-16y (mean: 9.13±3.70y) were studied. Male with female ratio was 1:1.7. The modal age range was 6-10y (42.4%). Most of them were primary school students (n=36, 54.5%). The predominant parents’ occupation was traders/unskilled workers (51.6%) and the professionals/civil servants (30.3%). The mean right and left VA were 0.45±0.46 and 0.45±0.44 (logMAR) respectively. The mean right and left horizontal corneal diameters (HCD) were 10.5±1.6 and 10.37±1.45 mm respectively. The mean right and left vertical corneal diameters (VCD) were 9.7±1.2 and 9.7±1.3 mm respectively. The mean right and left CCT were 556.71±2.61 and 556.47±45.53 µm respectively. Myopia (n=23, 34.8%), myopic astigmatism (n=18, 27.3%) and simple astigmatism (n=16, 24.2%) were the commonest types refractive error. No significant associations were observed between CCT and HCD (P=0.739), VA (P=0.058) and refractive error (P=0.199). However, CCT slightly significantly correlated with the age groups (P=0.055). CONCLUSION: Mean values for CCT, IOP and CD are known for the first time in Nigerian children. There is no significant association between CCT and VA, CD and refractive errors.

Evaluation of Primary Pterygia on Basis of the Loss of Vertical Length of Plica Semilunaris.

PurposeTo propose a new grading system for primary pterygia based on the morphological loss of vertical length of plica semilunaris (LPS).MethodsWe included 50 eyes from 41 patients with primary pterygium. LPS was defined and quantified as the ratio of the length of loss of the normal vertical morphology at plica semilunaris to the vertical corneal diameter using anterior-segment photographs. Grades of tear metalloproteinase 9 (MMP-9) expression by point-of-care immunoassay, which is a well-known biomarker for inflammation, was correlated with the extent of LPS (%) of pterygia. Then, LPS was paralleled with the pre-established grading systems on the basis of tissue translucency (i.e., T grade) and vascularity (i.e., V grade) of the pterygium body.ResultsMMP-9 grades was 2.39 ± 1.12 in the group with LPS ≥50% and was 1.56 ± 1.12 in the group with LPS <50% (P = 0.016). In a linear regression, the extent of LPS was positively correlated with MMP-9 grades (r = 0.315, P = 0.026). MMP-9 expression did not differ between T grades or V grades. The extents of LPS were well correlated positively with both T grades (r = 0.495 and P < 0.001) and V grades (r = 0.344 and P = 0.015).ConclusionsWe devised a new grading system using LPS on the basis of morphological loss of the normal vertical plica semilunaris in primary pterygia. The extent of LPS correlated well with T grades and V grades and also reflected the expression of MMP-9 in tears.Translational RelevanceThe new clinical LPS grading system reflects severity and MMP-9 expression in tears in primary pterygia.

Preliminary Anatomical Assessment of the Eye of the African Giant Rat (Cricetomys gambianus)

Eleven African giant rats were caught, bilaterally enucleated and the globes were routinely processed for light microscopy. Eye weight, vertical and horizontal corneal diameters, as well as vertical, horizontal and axial eye diameters were obtained from each globe. Observed external macroscopic ocular features were typical of mammalian eyes comprising cornea, sclera and attached extraocular muscles. The eye dimensions were however generally smaller than those of humans. The large mean corneal diameter to mean eye diameter ratio of 0.86 as well as the scanty retinal ganglion cells observed are associated with morphological adaptations for nocturnal vision. Pigments observed in the retinal epithelium suggests absence of tapetum lucidum, indicating a sub-optimal nocturnal visual capability. This study has provided scientific documentation of some ocular morphological characteristics of the giant rat and has shown that the eye of this species will be anatomically unsuitable for xenotransplantation in humans.

Retinitis pigmentosa with bilateral irido-fundal coloboma

A 40-year-old male, presented with gradual painless progressive loss of vision in both the eyes more in right since 1 year. Born out of consanguineous marriage, he gave a history of night blindness since childhood. The best-corrected visual acuity was 20/200 and 20/40 in right and left eye, respectively. Refraction showed an axial myopia of -9.00 DS/-1.50 DC at 100 degree in the right eye. The left eye showed refraction of +1.00 DC at 170 degree. Intraocular pressure with noncontact tonometer was 15 and 16 mm of Hg. Axial length was found to be 24.93 mm and 23.60 mm in right and left eye, respectively. Vertical and horizontal corneal diameters were 11 mm in both eyes. Keratometry values in the right eye were K vertical 43.55D, K horizontal 44.06D and in the left eye were K vertical 43.05D, K horizontal 43.49D. Slit-lamp examination revealed a clear cornea and normal anterior chamber depth. Inferonasal iris coloboma was noted in both eyes [Fig. 1]. The lens showed nuclear sclerosis grade 2 with posterior subcapsular opacification in right and nuclear sclerosis grade 2 in the left eye according to the Lens Opacities Classification System II (LOCS II) The posterior segment showed a normal-looking disc with minimal arteriolar attenuation, boney spicules distributed from the mid periphery throughout the retina in both eyes. Chorio-retinal coloboma was type 3 (separated from the optic disc by a clear area of the retina) in the right eye [Fig. 2] and type 7 (extreme peripheral coloboma) in the left eye [Fig. 3] according to Ida Manns classification. B scan ultrasonography showed an excavated lesion in the inferior aspect suggestive of fundus coloboma in the right eye. In the left eye the coloboma was not well demarcated on B scan ultrasonography.Figure 1: Anterior segment photographs with diffuse illumination (a) Right eye showing inferonasal iris coloboma with cataractous lens. (b) Left eye showing inferonasal iris colobomaFigure 2: (a) Fundus photograph of right eye showing coloboma in the inferior quadrant sparing disc and macula with bony spicules in the mid periphery. (b) Fundus photograph right eye, superonasal quadrant showing bony spicules in the mid peripheryFigure 3: (a) Fundus photograph of left eye depicting bony spicules in mid periphery and extreme peripheral coloboma inferiorly. (b) Peripheral coloboma with bony spicules in inferior quadrantPhacoemulsification with intraocular lens implantation under topical anesthesia was done in the right eye. Postoperatively at the end of 1 month best-corrected visual acuity was 20/30 in the right eye with a refraction of -0.75 DC at 80 degrees and near vision of N6 with + 3.00 DS. Discussion Retinitis pigmentosa is most commonly associated with posterior subcapsular cataract 53%[1] glaucoma 2.3%[2] myopia, keratoconus, vitreous detachment, and optic disc drusen. Association of macular colobomas with retinitis pigmentosa, especially autosomal dominant RP and Ushers syndrome has been extensively reported in the literature. In 2004, phenotypically different RP with macular coloboma was reported by Parmeggiani in 3 adult siblings[3], which was stated as an autosomal dominant feature. The association of iris and fundal coloboma with RP has been rarely reported in the literature. Kelly et al.[4] described the incidence, ocular findings, and systemic associations of coloboma in a population-based cohort study in the United States, reported one case with unilateral coloboma in association with RP. Population-based studies in India are scanty. Pallavi Agrawal et al.[5] reported a similar case of unilateral coloboma from a case in Mumbai, India in 2013. Bilateral Irido-fundal coloboma and RP can be separate entities occurring together in this case, or it could be a rare association. Similar cases/case series need to be reported to come to a conclusive result. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

A Cohesin Subunit Variant Identified from a Peripheral Sclerocornea Pedigree.

Background Sclerocornea is a rare congenital disorder characterized with the opacification of the cornea. Here, we report a nonconsanguineous Chinese family with multiple peripheral sclerocornea patients spanning across three generations inherited in an autosomal dominant manner. Methods This is a retrospective case series of a peripheral sclerocornea pedigree. Comprehensive ophthalmic examinations were conducted and assessed on 14 pedigree members. Whole-exome sequencing was used to identify the genetic alterations in the affected pedigree members. Lymphoblastoid cell lines (LCLs) were established using blood samples from the family members. Functional tests were performed with these cell lines. Results Six affected and eight unaffected members of a family with peripheral sclerocornea were examined. All affected individuals showed features of scleralization over the peripheral cornea of both eyes. Mean horizontal and vertical corneal diameter were found significantly decreased in the affected members. Significant differences were also observed on the mean apex pachymetry between affected and unaffected subjects. These ophthalmic parameters did not resemble that of cornea plana. A RAD21C1348T variant was identified by whole-exome sequencing. Although this variant causes RAD21 R450C substitution at the separase cleavage site, cells from peripheral sclerocornea family members had no mitosis and ploidy defects. Conclusion We report a family of peripheral sclerocornea with no association with cornea plana. A RAD21 variant was found cosegregating with peripheral sclerocornea. Our results suggest that RAD21 functions, other than its cell cycle and chromosome segregation regulations, could underline the pathogenesis of peripheral sclerocornea.

Anatomical Assessment of the Eye of the African Grasscutter (Thryonomys swinderianus)

Purpose: To determine the macroscopic and microscopic ocular morphological characteristics of the African grass-cutter&#x0D; Materials and Methods: Ten male grasscutters of mean age 4.05 ± 1.44 months and mean weight 1.04 ± 0.56 kg were used for this study. Gross morphologic and light microscopic techniques were employed in the study of the eyes.&#x0D; Results: Grossly, the eye exhibited typical characteristics of the mammalian eye with a mean eye weight and mean corneal diameter of 0.47 ± 0.14 g and 0.73 ± 0.07 cm, respectively. The horizontal corneal diameter was significantly greater (p &lt; 0.05) than the vertical corneal diameter, and the ratio of mean corneal diameter to mean eye diameter (MCD:MED) was 0.80. The sclera and corneal stroma were dense fibrous connective tissues and had thicknesses of 105.3 ± 25.8 µm and 201.4 ± 91.3µm, respectively, while the corneal epithelium was stratified squamous epithelium and measured 50.1 ± 15.1µm. The choroid, ciliary stroma, and iridal stroma were pigmented connective tissues, while the retina was a multi-layered neuro-epithelial tissue with scanty ganglion cells and a retinal pigment epithelium that was pigmented throughout its length.&#x0D; Conclusion: The high MCD:MED and scanty retinal ganglion cells observed are associated with nocturnal visual capability. However, the complete pigmentation of the retinal pigment epitheliumsuggest the absence of tapetum lucidum in this species. This could considerably lower its nocturnal visual capability and indicate a low reliance on vision for environmental perception. The biometrical measurements obtained have made data available for use in future ocular studies of the rodent.

Corneal Endothelial Cell Density in Uveal Coloboma Associated With Microcornea.

To evaluate the relationship between endothelial cell density (ECD) and mean corneal diameter (MCD) in eyes with uveal coloboma associated with microcornea. Corneal endothelial cell imaging was performed using specular microscopy on 22 eyes of 18 subjects diagnosed with uveal coloboma associated with microcornea. The MCD was noted as the average of horizontal and vertical corneal diameters, which were measured using the ruler tool of the slit-lamp biomicroscope and Castroviejo calipers. Mean age of the study subjects was 29.7 ± 10.4 years (range, 14-46 years). The MCD was 7.3 ± 1.1 mm (range, 4.9-9 mm). Mean ECD (3436 ± 316.2 cells/mm) of the study subjects was significantly (P < 0.0001) higher than the mean ECD (2761.8 ± 140.9 cells/mm) of age-matched (range, 10-40 years) normal eyes with no ocular pathology. The pleomorphism and polymegathism were comparable between the 2 groups. Regression analysis showed that MCD had a significant negative (R = -0.55; P = 0.02) relationship with ECD. Eyes with congenital uveal coloboma associated with microcornea have increased ECD. Increased ECD may be partly due to a reduced posterior corneal surface area in microcornea.

SELECTED OPHTHALMIC PARAMETERS AND POTENTIAL RISK FOR LIGHT-INDUCED CATARACTS IN TWO COLONIES OF CAPTIVE INDIAN FLYING FOXES ( PTEROPUS GIGANTEUS).

Indian flying foxes ( Pteropus giganteus) are adapted to visual foraging in dim light. Nine Indian flying foxes were taken from a captive colony of 25 animals and placed in quarantine, off exhibit, in preparation for shipment to another institution. The exhibit had indirect, natural sunlight and was large enough to allow for flight. The quarantine enclosure was subject to >12 hr/day artificial lighting and did not allow for flight or gliding. Diet was identical between groups. After 13 mo, ophthalmic examination was performed on each animal including evaluation of the anterior chamber, rebound tonometry in upright and hanging positions, measurement of palpebral fissure length, and vertical and horizontal corneal diameters. Bilateral cataracts were observed in 55% (5/9) of the quarantined animals but in none of the animals that remained on exhibit (0/16). Bats housed in the quarantine enclosure had a risk of having cataracts 18 times greater than did bats in the exhibit enclosure (relative risk [RR]: 18.70; 95% confidence interval [CI]: 1.15-303.77). There was no association between cataract presence and age (odds ratio [OR]: 0.99; 95% CI: 0.97-1.02; P = 0.7) or sex (OR: 1.24; 95% CI: 0.17-9.25), but lower body weight was associated with presence of cataracts (OR: 0.98; 95% CI: 0.96-0.99). Other ophthalmic parameters observed were similar to those previously reported for other captive Megachiroptera. This study suggests that chronic exposure to artificial lighting predisposes fruit bats to developing light-induced cataracts.

The eye of the Barbary sheep or aoudad (Ammotragus lervia): reference values for selected ophthalmic diagnostic tests, morphologic and biometric observations.

The purpose of this study was to describe the normal ocular anatomy and establish reference values for ophthalmic tests in the Barbary sheep or aoudad (Ammotragus lervia). Aoudad eyes are large and laterally positioned in the head with several specialized anatomic features attributed to evolutionary adaptations for grazing. Normal values for commonly used ophthalmic tests were established, Schirmer tear test (STT) - 27.22 ± 3.6 mm/min; Predominant ocular surface bacterial microbiota - Staphylococcus sp.; Corneal esthesiometry- 1.3 ± 0.4 cm; Intraocular pressure by rebound tonometry- 19.47 ± 3.9 mmHg; Corneal thickness- 630.07 ± 20.67 µm, B-mode ultrasonography of the globe-axial eye globe length 29.94 ± 0.96 mm, anterior chamber depth 5.03 ± 0.17 mm, lens thickness 9.4 ± 0.33 mm, vitreous chamber depth 14.1 ± 0.53 mm; Corneal diameter-horizontal corneal diameter 25.05 ± 2.18 mm, vertical corneal diameter 17.95 ± 1.68 mm; Horizontal palpebral fissure length- 34.8 ± 3.12 mm. Knowledge of these normal anatomic variations, biometric findings and normal parameters for ocular diagnostic tests may assist veterinary ophthalmologists in the diagnosis of ocular diseases in this and other similar species.

Fetal orbital and ocular biometry at different gestational ages

IntroductionDetermination of orbital and ocular growth patterns in fetal life is necessary for early diagnosis of facial malformation syndromes. We aim to establish the normative data for growth of different ocular and orbital parameters. These parameters may also correlate with fetal anthropometry. MethodsFifty normal fetuses at different gestational ages were studied for anthropometric, orbital and ocular growth. The parameters measured included weight, height, biparietal diameter, depth and width of the orbit, interorbital distance, transverse and vertical corneal diameters, axial and transverse diameters of the eyeball and diameter of the lens. Normative values were determined for orbital and ocular parameters in fetuses of 11–36 gestational weeks. ResultsThe orbital and the ocular parameters demonstrated significant positive correlation with age and biparietal diameter. However, the lens diameter did not show any significant correlation with either age or biparietal diameter. Among orbital parameters interorbital distance showed maximum correlation with biparietal diameter. The correlations of orbital and ocular parameters were better defined in males. ConclusionsThe gestational age specific normative data generated in this study may provide reference for comparing the growth of various orbital and ocular parameters and may aid in early diagnosis of fetal maldevelopment syndromes.

Association of height, body weight, age, and corneal diameter with calculated intraocular lens strength of adult horses

To determine whether differences exist in the calculated intraocular lens (IOL) strengths of a population of adult horses and to assess the association between calculated IOL strength and horse height, body weight, and age, and between calculated IOL strength and corneal diameter. 28 clinically normal adult horses (56 eyes). Axial globe lengths and anterior chamber depths were measured ultrasonographically. Corneal curvatures were determined with a modified photokeratometer and brightness-mode ultrasonographic images. Data were used in the Binkhorst equation to calculate the predicted IOL strength for each eye. The calculated IOL strengths were compared with a repeated-measures ANOVA. Corneal curvature values (photokeratometer vs brightness-mode ultrasonographic images) were compared with a paired t test. Coefficients of determination were used to measure associations. Calculated IOL strengths (range, 15.4 to 30.1 diopters) differed significantly among horses. There was a significant difference in the corneal curvatures as determined via the 2 methods. Weak associations were found between calculated IOL strength and horse height and between calculated IOL strength and vertical corneal diameter. Calculated IOL strength differed significantly among horses. Because only weak associations were detected between calculated IOL strength and horse height and vertical corneal diameter, these factors would not serve as reliable indicators for selection of the IOL strength for a specific horse.

Cataract surgery and intraocular lens implantation in anterior megalophthalmos.

Dear Sir, I am Dr. Yun Li, from the Second Hospital Affiliated to Nanchang University, Jiangxi Province, China. I write to present a case report of IOL implantation in anterior megalophthalmos. Anterior megalophthalmos (AM) is the term suggested by Vail [1] to define bilateral enlargement of the anterior segment of the eyeball in the absence of an increased intraocular pressure. It is a rare hereditary condition characterized by megalocornea (diameter greater than 12.0mm), enlarged ciliary ring, stromal atrophy, iris hypoplasia, lens subluxation or dislocation, and cataract formation at an early age. The most common cause of visual impairment is the development of premature cataract, the extraction of which is prone to complications ,especially when the crystalline lens is luxated or subluxated. The enlarged ciliary ring and capsular bag are deterrents to easy insertion of standard posterior chamber intraocular lenses (IOLs) which are likely to decenter. Since its first description as a distinct entity by Vail in 1931, there have been a few reports about different techniques of cataract surgery and IOL implantation in Europe. However, to our knowledge, no reports of cataract extraction and IOL implantation in megalophthalmos have been reported in Asia. Here we report a case of AM and describes how we managed the anterior megalophthalmos and present a new technique of standard posterior chamber IOL implantation which resulted in successful visual rehabilitation. A 57-year-old man was referred to our department with bilateral progressive loss of vision and family history of ocular disease was negative. Visual acuity was light sensation without correction in the right eye and 20/40 with -6.50-2.00 伊85 in the left. Horizontal and vertical corneal diameters (measured with a pair of callipers under anesthesia) were 13.0mm and 12.0mm in both eyes, respectively. Axial lengths were 25.10mm in the right eye and 25.52mm in the left eye. The anterior chambers were 3.65mm deep in the right eye and 3.94mm deep in the left eye measured by UBM which showed that the anterior chamber angle was widely open. Bilaterally, localized corneal opacity was seen and irides showed marked moderate stromal atrophy and transillumination defects with iridodonesis. The pupil of either eye could not be fully dilated after pharmacologic mydriasis. The lens in the right eye was severely opaque and intumescent while the lens in the left eye showed moderate nuclear sclerosis (Figure 1). The fundus of the right eye could not be seen because of severe nuclear sclerotic cataract. The cup-to-disc (c/d) ratio in the left eye was 0.3 with healthy neuroretinal rim, and the retina was normal. Intraocular pressure was normal in both eyes. An uneventful planned extracapsular cataract extraction was performed in the right eye. A 4.0mm 2-plane limbus tunnel incision was constructed. DisCoVisc (Alcon) was used as the viscoelastic agent to maintain the anterior chamber, and can-opener anterior capsulotomy was performed. The nucleus was hydrodissected and delivered by manual expression, and the cortex was removed with a silicone irrigation/aspiration tip. Because of the larger diameter of the ciliary ring of anterior megalophthalmos, it is suggested to implant a posterior chamber IOL with a lens diameter of 16.0 to 18.0mm [7]. However, such an IOL was not available. Under the circumstances, a posterior chamber IOL (Matrix Acrylic Aurium) with a 6.0mm optic and an overall length of 12.5mm was selected. The intraocular lens had a power of 19.50 diopters (D) determined by the SRK formula. After placing the IOL in the capsular bag, we let the patient sit up for 2 minutes, discovering that the IOL was dislocated temporally (Figure 2). As a result, we pulled the IOL from the capsular bag into the anterior chamber and made a haptic of the IOL outside the eye. From the limbus tunnel incision, one end of a double-armed 10-0 nylon suture was passed through the iris and the anterior capsule at 12 o'clock and passed from within the capsular bag, to emerge through IOL implantation in anterior megalophthalmos

Age, gender, corneal diameter, corneal curvature and central corneal thickness in Nigerians with normal intra ocular pressure

PurposeTo investigate the relationship between age, gender, corneal diameter, central corneal curvature, central corneal thickness (CCT) and intraocular pressure in Nigerians with normal intraocular pressure. MethodsOne hundred and thirty eyes from 130 subjects (mean age=47.8±16.8 years) including 77 males and 53 females were recruited. CCT was measured by ultrasound pachymetry, intraocular pressure was determined by non-contact tonometry, horizontal and vertical corneal diameters were measured with a ruler and central corneal curvature was measured by keratometry. ResultsThe mean values obtained were as follows: CCT=548.97±34.28μm, IOP=15.61±2.69mmHg, average corneal curvature (AVK)=42.98±1.19 D, horizontal corneal diameter (HVID)=11.39±0.69mm and vertical corneal diameter (VVID)=10.51±0.50mm. There was a significant effect of age on CCT (r=−0.35, p<0.001). A 10-year-increase in age was associated with a 7.0μm decrease in CCT. Males had significantly wider HVID than females (p=0.03). Subjects in older age groups have narrower HVID and VVID. Corneal curvature, corneal diameter and gender did not significantly affect CCT. ConclusionCCT of normotensive Nigerian adults decreases with increasing age. There was no correlation between CCT and IOP in normotensive subjects. CCT was not significantly influenced by gender, corneal curvature and corneal diameter.

Repeatability of automatic measurements performed by a dual Scheimpflug analyzer in unoperated and post-refractive surgery eyes

To assess the repeatability of the anterior segment measurements performed with a dual Scheimpflug analyzer (Galilei) in unoperated and post-refractive surgery eyes. Private practice. Evaluation of diagnostic test. Three consecutive scans were acquired in unoperated eyes and in eyes that had excimer laser surgery for myopia. Unoperated eyes were enrolled from 3 subgroups: younger than 50 years, aged between 50 and 70 years, and older than 70 years. The following parameters were evaluated: simulated keratometry, posterior corneal power, total corneal power, anterior and posterior best-fit sphere radius, mean and thinnest central corneal thickness, anterior chamber depth and volume, horizontal and vertical corneal diameter, iridocorneal angle in the 4 quadrants, and corneal spherical aberration. Repeatability was assessed using analysis of variance (ANOVA), the coefficient of variation (COV), intraclass correlation (ICC), and test-retest variability. The study evaluated 45 unoperated eyes (n = 45) and 15 post-refractive surgery eyes (n = 15). Each age subgroup in the unoperated group comprised 15 eyes. The ANOVA did not detect significant differences between the 3 measurements for any parameter. The COV was less than 0.5% for corneal power measurements and less than 3.5% for all remaining parameters except spherical aberration (16.68%). The ICC was more than 0.99 for corneal power measurements and more than 0.94 for all remaining parameters. The anterior segment measurements provided by the dual Scheimpflug analyzer were highly repeatable. Repeatability did not change with age or after myopic photorefractive keratectomy or laser in situ keratomileusis.

Ocular parameters in a captive colony of fruit bats

To establish normal reference ranges of ocular parameters including phenol read thread, palpebral fissure length, horizontal and vertical corneal diameter, upright and hanging intraocular pressure (IOP) and to report ophthalmic examination findings of the anterior segment and lens, in a population of captive fruit bats. Eyes of 30 bats of three species were included in this study: 10 (5 males, 5 females) Malayan Flying Foxes (Pteropus vampyrus), 10 (5 males, 5 females) Little Golden-mantled Flying Foxes (Pteropus pumilus), and 10 (4 males, 6 females) Island Flying Foxes (Pteropus hypomelanus). The most common ophthalmic examination findings included iris-iris persistent pupillary membranes (83%), nuclear sclerosis (56.7%), prominent arterial circle (40%), iridal hyperpigmented foci (30%), pupillary margin cysts (27%), and third eyelid defects (20%). The mean, among all species for: phenol red thread was 20.23 ± 1.28 mm/15 s both eyes (OU); palpebral fissure length was 13.34 ± 0.33 mm for OU; for horizontal corneal diameter was 10.72 ± 0.32 mm for OU; for vertical corneal diameter was 9.90 ± 0.30 mm for OU; for the hanging intraocular pressures was 19.38 ± 0.77 mmHg for OU; for upright IOP was 13.95 ± 0.60 mmHg for OU. Measurements for the individual species groups and eyes were also calculated. Results revealed the IOP of bats in a hanging position were significantly higher than the IOP of bats in an upright position. The size of the bat, between the species, affected palpebral fissure length, horizontal corneal diameter, and vertical corneal diameter. Information about the ocular structures and normal ophthalmic parameters for the Pteropus species is crucial for species protection because of dependence on vision for survival.

Evaluation of healthy equine eyes by use of retinoscopy, keratometry, and ultrasonographic biometry

To assess natural variations in degree of refraction, corneal curvature, corneal astigmatism, corneal radius, and intraocular distance of healthy equine eyes. 159 horses with healthy eyes that were admitted to a veterinary teaching hospital for nonophthalmic surgeries. Eyes of horses were examined with a retinoscope prior to anesthesia and with a keratograph and A- and B-scan ultrasonographic biometers during surgery. In addition, manual caliper measurements of horizontal and vertical corneal radii were obtained. Mean +/- SD degree of refraction in the horizontal meridian of eyes was -0.06 +/- 0.68 diopters (D). Vitreous body length and horse age correlated negatively with refraction values. The horizontal corneal radius (15.96 +/- 1.28 mm) was larger than the vertical corneal radius (15.02 +/- 1.09 mm). Accordingly, the vertical corneal curvature (21.56 +/- 1.68 D) was greater than the horizontal corneal curvature (22.89 +/- 1.65 D). Axial globe length (40.52 +/- 2.67 mm), anterior chamber depth (6.35 +/- 0.59 mm), lens thickness (12.30 +/- 0.83 mm), and vitreous body length (21.87 +/- 1.85 mm) were positively correlated with body weight, height, and age. Results of keratograph and caliper measurements correlated well for horizontal corneal diameter but poorly for vertical corneal diameter. Results of A- and B-scan ultrasonography differed by < or = 1 mm in 64% of measured eyes. Results of keratometry and ultrasonographic biometry varied widely. Additional research is needed to validate the keratograph used in our study for measurements in equine eyes.

Evaluation of the relationship between corneal diameter and lens diameter

To investigate the relationship between corneal diameter (white to white) (WTW) and the dimensions of the crystalline lens. Private practice, Cincinnati, Ohio, USA. Human cadaver eyes were oriented to allow caliper measurements of the horizontal and vertical corneal diameters (WTW). Globes were sectioned and reoriented so the horizontal and vertical measurements of the crystalline lens were recorded and statistically analyzed. The mean horizontal corneal diameter was 11.46 mm, approximately 0.8 mm greater than the mean vertical corneal diameter of 10.63 mm. The mean horizontal crystalline lens diameter was 9.28 mm, nearly identical to the mean vertical diameter of 9.30 mm. The correlation between the mean corneal diameter and mean lens diameter was weak, although it was significant. There was no correlation between horizontal dimensions. It was not possible to predict the dimensions of the human crystalline lens using calipers to measure the WTW corneal diameter.