Length Of Globe Research Articles

CLINICAL OPHTHALMIC PARAMETERS OF THE TEXAS TORTOISE (GOPHERUS BERLANDIERI).

Ophthalmic studies of the Texas tortoise (Gopherus berlandieri) established normal ophthalmic parameters for select diagnostic tests in captive tortoises and assessment of differences among individuals of differing size and health status. Sixty-one tortoises of varying weight, shell size, Mycoplasma seroprevalence, and herpesvirus exposure were included. Complete ophthalmic examinations, including neuro-ophthalmic reflexes, phenol red thread test, rebound tonometry, fluorescein staining, palpebral fissure length measurement, slit lamp biomicroscopy, indirect fundoscopy, and ocular ultrasound measurements of axial globe length, anterior chamber depth, lens thickness, and vitreous length, were recorded. All tortoises had negative dazzle and pupillary light reflexes, inconsistent menace responses, and positive palpebral reflexes. Mean ± SD tear production and intraocular pressure (IOP) were 14.2 ± 5.6 mm/15 sec and 13.8 ± 2.4 mm Hg in healthy tortoises, respectively. Mycoplasma-seropositive tortoises (with or without herpesvirus exposure) had significantly increased tear production (20.2 ± 8.1 and 19.9 ± 8.9 mm/15 sec, respectively) compared with healthy seronegative tortoises (14.2 ± 5.6 mm/15 sec; P = 0.02). As body size decreased, so too did palpebral fissure length and ocular ultrasound measurements, while IOP increased. Overall, palpebral fissure length appeared relatively small, and tear production relatively increased compared with other chelonian species, likely on the basis of the relatively arid native habitat. Further work is recommended to establish baseline values in related species, as well as comparison in aquatic versus terrestrial chelonians. The authors further suggest that the finding of relatively increased tear production in tortoises may indicate the need to rule out mycoplasmosis as a cause of upper respiratory tract disease.

A study of the various etiologies and sequelae to ectropion and entropion

Purpose: This study aims to analyze the different etiologies of ectropion and entropion and helps in understanding the anatomical abnormalities responsible for the occurrence of entropion and ectropion, which is key to planning a successful surgical procedure. Methodology: It is a prospective study of 40 patients with ectropion and entropion studied for 17 months. Detailed slit lamp examination of lid abnormality, keratinization, trichiasis, corneal exposure was performed and axial length was measured. Results: The prevalence of ectropion and entropion put together was 0.064%. Paralytic ectropion ranks first among the different etiologies occupying 65.38%. The senile cause is the highest (78.57%) among the etiologies of entropion. The mean axial globe length of affected eyes in senile ectropion is 21.96 mm and in senile entropion is 20.73 mm. Conclusion: Eyelid malpositions have a low prevalence of 0.064%. The difference in the mean axial globe length between senile ectropion and entropion for this small sample size was found to be statistically significant. The overall percentage of conjunctival and corneal complications was found to be significantly higher in ectropion than in entropion.

Ocular ultrasonography of sea turtles

BackgroundEnvironmental changes contribute to the development of ophthalmic diseases in sea turtles, but information on their eye biometrics is scarce. The aim of this study was to describe ophthalmic ultrasonographic features of four different sea turtle species; Caretta caretta (Loggerhead turtle; n = 10), Chelonia mydas (Green turtle; n = 8), Eretmochelys imbricata (Hawksbill turtle; n = 8) and Lepidochelys olivacea (Olive ridley; n = 6) under human care. Corneal thickness, scleral ossicle width and thickness, anterior chamber depth, axial length of the lens, vitreous chamber depth and axial globe length were measured by B-mode sonography with a linear transducer. Carapace size and animal weight were recorded. A sonographic description of the eye structures was established.ResultsThe four species presented an ovate eyeball, a relatively thin cornea, and a small-sized lens positioned rostrally in the eye bulb, near the cornea, resulting in a shallow anterior chamber. The scleral ossicles did not prevent the evaluation of intraocular structures, even with a rotated eye or closed eyelids; image formation beyond the ossicles and measurements of all proposed structures were possible. B-mode sonography was easily performed in all animals studied. The sonographic characteristics of the eye were similar among the four species. Since there was a correlation between the size of the eye structures and the size of the individual, especially its carapace size, the differences found between E. imbricata and Caretta caretta are believed to be due to their overall difference in size.ConclusionsSonography is a valuable tool in ophthalmic evaluation of these species. Only minor differences were found between the species in this study, reinforcing their phylogenetic proximity and their similar functions and habitats.

Macroscopic morphological aspects, ecometry and rebound tonometry of the eye bulb in sloth (Bradypus variegatus)

ABSTRACT: The field related to the visual system of wild animals is deeply scarce. Settling anatomical and physiological parameters for these animals is still a descriptive vision for Bradypus variegatus (Schinz, 1825). Thus, our research aimed to determine patterns of normal eye for this species. For this purpose, eight eye bulbs were dissected from the carcasses obtained by natural death, and then performed an overview of ocular anatomical. Rebound tonometry (RBT) and ocular B-mode ultrasonography were also applied for eight eyes in four animals from “Parque Estadual Dois Irmãos”, situated in the city of Recife, state of Pernambuco (PE), to estimate the intraocular pressure and ocular ecobiometry. The ocular morphology of sloth is similar as described for other species, however, with some peculiarities. They present a third eyelid emerging in the nasal region of the inferior conjunctival sac and retina and also contain little differentiated blood vessels. Medium the intraocular pressure (IOP) was 4.25mmHg with no difference for both eyes. Ultrasonography of ocular anatomy is also similar regarding other species. Ecobiometric patterns were evaluated to determine the anterior chamber depth, lens width, vitreous chamber depth, and axial length (AL) of ocular globe and the averaged as shown 0.63±1.11mm, 3.73±0.24mm, 6.15±0.41mm, 3.70±0.27mm, and 8.48±0.22mm, respectively. There was no difference between the right and left eyes. The RBT and ocular B-mode ultrasonography are fast exams and easy for animal testing. This study contributed to the characterization of ocular anatomy as well as settling medium values of IOP and intraocular measures; however, further research on physiology and histology is necessary to better understand the visual function of the species.

Ophthalmic examination, biometry, and histologic findings in captive inland bearded dragons (Pogona vitticeps).

To report ophthalmic examination, biometry, phenol red thread test (PRTT), intraocular pressure (IOP), and histologic findings from a private collection of inland bearded dragons (Pogona vitticeps). Fourteen inland bearded dragons. Complete ophthalmic examinations were performed on all animals, including slit-lamp biomicroscopy, indirect ophthalmoscopy, fluorescein stain, phenol red thread test, and rebound tonometry. B-mode ultrasonography was used to measure anterior chamber depth, axial lens thickness, vitreal chamber depth, and axial globe length. Horizontal corneal diameter was estimated using ImageJ software. Histologic assessment was obtained for one of the bearded dragons that died following the study period. The median PRTT value was 7.27mm/15seconds. Mean IOP was 6.29±1.60mmHg and 2.14±1.37mmHg using the dog and undefined calibration settings, respectively. Median axial globe length was 11.75mm. Mean anterior chamber depth and mean lens thickness were 2.06±0.35mm and 3.38±0.45mm, respectively. Median vitreal chamber depth was 6.79mm. Mean horizontal corneal diameter was 5.138±0.346mm. Two distinct ocular phenotypes were observed, with two of the bearded dragons having corneal globosa, deep anterior chambers, and tufts of iridal vessels and fibrillar material extending into the anterior chamber. The ultrasound biometry, PRTT, and rebound tonometry results may serve as a guideline for ophthalmic parameters in healthy bearded dragons. Examination and testing of greater numbers of animals are necessary to establish true reference ranges and determine if the observed ocular phenotypes represent normal variants or pathologic changes.

Normative ocular data for juvenile and adult Japanese quail (Coturnix japonica).

To obtain normative ocular data for Japanese quail as they mature from juveniles to adults. Twenty-six captive Japanese quail comprising thirteen males and thirteen females, free of ocular disease, were included in the study. Ophthalmic reference values were measured in both eyes at 1 and 5months of age. A complete ophthalmic examination was performed, including neuro-ophthalmic reflexes, slit lamp biomicroscopy, phenol red thread test (PRTT), rebound tonometry, fluorescein staining, horizontal corneal diameter measurement, indirect ophthalmoscopy, and ocular ultrasound biometry. Ultrasound biomicroscopy measurements of axial globe length, lens thickness, vitreal chamber length, and pecten length were recorded. The depth of the anterior chamber was calculated by subtracting the lens thickness and vitreous length from the axial globe length. Measures of association and descriptive statistics were analyzed using STATA-14 and STATA-15. Juvenile and adult females were heavier than age-matched males. Weight, intraocular pressure, horizontal corneal diameter, axial globe length, and lens thickness measurements increased with age. No statistically significant differences were found in the remainder of measurements among individuals in different sex or age-groups. This work provides reference values and clinical findings that can be used in future research on quail and ocular disease.

Comparison of Transcorneal and Transpalpebral Ultrasonographic Measurements of the Eye in Iranian Mix Breed Dog

Objective-The aim of this research was to compare transcorneal and transpalpebral ultrasonography study of the dimensions (ecobiometry) and the ultrasonographic aspect of Iranian mix breed dogs.Design- Experimental studyAnimals- . Ten adult male dogsProcedure- Ten adult male dogs with the mean age 4±1.39 years and the mean weight of 16.7±3.6 kg were selected and distributed in two equal groups. Transcorneal and transpalpebral ultrasonographic scanning of left and right eyes of dogs were performed using with a 12 MHZ transducer. The transducer was placed in a longitudinal position (sagittal plane) until optimal B-scan images, were obtained.Results- Means and standard deviations of the intraocular structures of both transcorneal and transpalpebral were as, Anterior chamber depth (2.99±0.242, 2.78±0.285 mm), Lens thickness (6.62±0.364,7.02±0.612 mm), Vitreous chamber depth (8.81±0.354, 8.79±0.552 mm) and Axial globe length (19.60±0.452,19.50±0.592 mm) respectively. No significant differences were observed when comparing left and right eyes of dogs in both methods within the same group and comparing between two groups (p>0.05).Conclusion and Clinical Relevance- Results of this study can be used as a template in diagnosis of ocular disease and facilitates the use of transpalpebral ultrasonography in the evaluation of ocular structures in ocular disease specially painful conditions.

INTRAOCULAR PRESSURE, TEAR PRODUCTION, AND OCULAR BIOMETRY IN HEALTHY ADULT CHEETAHS (ACINONYX JUBATUS).

Schirmer tear test (STT), intraocular pressure (IOP), and ocular biometry were measured in 58 healthy cheetahs (Acinonyx jubatus) between the ages of 2 and 14 yr in two captive groups. During routine health examination under immobilization, each animal underwent ophthalmic examination including STT, IOP, slit-lamp biomicroscopy, indirect ophthalmoscopy, and ocular ultrasonography. Mean ± SD values for STT and IOP were 13.58 ± 5.29 mm/min and 31.40 ± 5.01 mm Hg, respectively. The time between immobilization and examination significantly influenced both STT and IOP measurements. For IOP measurements, a significant group effect was also demonstrated, possibly due to the different anesthetic drug combinations used. Mean ± SD values for biometry were as follows: globe length (32.73 ± 1.74 mm), lens thickness (7.25 ± 1.09 mm), anterior chamber (8.54 ± 1.21 mm), and posterior segment (16.31 ± 2.06 mm). Surprisingly, all of the biometry measurements differed significantly between the two groups. Establishing STT, IOP, and biometric reference values is important for evaluating the ocular health status of the species. These reference values will assist veterinarians working with cheetahs to perform a full and informed ophthalmic examination.

Ocular ultrasonographic evaluation of cataractous and pseudophakic eyes in dogs

Ocular B-mode ultrasonography is one of the noninvasive, rapid diagnostic imaging techniques indicated in canine cataract patients to evaluate the posterior segment of the eye. This study was conducted on twelve eyes of dogs with a history of cataract, which were scanned under topical anesthesia. The preoperative and postoperative ultrasonographic biometry, and ultrasonographic features of the lens, intraocular lens (IOL), and posterior segment were recorded. There was a significant difference between pre- and postphacoemulsification mean value of the axial length of globe and anterior chamber depth. The normal ultrasonographic features of the 2-hydroxy-ethyl-methylacrylate IOL was observed in vitro by placing the IOL in a coupling gel bath; it appeared as a flying saucer with hyperechoic margins and a central anechoic optic area and similar findings were also observed in pseudophakic eyes. Posterior segment changes such as posterior vitreous detachment were noticed in two dogs and retinal detachment in one dog postoperatively. In conclusion, ocular B-mode ultrasonography could be used to locate the position of the IOL in canine pseudophakic eyes. Ocular ultrasound is still more a useful tool to locate the position of the IOL postoperatively, even in pseudophakic eyes with corneal edema or iris synechiae in dogs.

Outcomes of cataract surgery in Microophthalmia.

Objective:To find out outcomes of cataract surgery with Microophthalmia in children less than two yearsMethods:This cross-sectional study was conducted at Al-Ibrahim Eye Hospital, Karachi from January 2016 to August 2017. It included thirty micro ophthalmic eyes of infants with visually significant cataract of age less than two years who had cataract surgery without intraocular lens implantation. Axial length of globe was 19 mm or less in all thirty eyes of seventeen infants. in which thirteen infants had bilateral cataract and four had unilateral cataract.Result:Thirty Simple Micro ophthalmic eyes from seventeen patients having visually significant congenital cataract were studied. Thirteen had bilateral cataract and four had unilateral cataract. Mean preoperative IOP was 9.0±1.2 mmHg and postoperative IOP after three months was 10.9±3.2 mmHg. Three patients had secondary capsular opacification 17.6%. Two patients had posterior synachae 11.8% after three months.Conclusion:The results suggest that cataract surgery in simple microophthalmia is safe procedure. Postoperative complications in this study were within acceptable limits. Long term study with intraocular lens is required to confirm our observation.

“The influence of orbital vector on involutional entropion and ectropion”

ABSTRACTPurpose: This study aimed to evaluate the effect of orbital vector and other biometric parameters (i.e. axial globe length, axial globe projection) on the development of involutional entropion or ectropion.Methods: In this cross-sectional study, 167 eyes from 132 patients were included. Of these eyes, 128 had involutional entropion and 39 had involutional ectropion, all of lower lids. The axial globe projection was measured using Hertel exophthalmometry; axial globe length was assessed by A-mode ultrasound; and orbital vector was determined clinically. Patient-specific categorical variables and continuous variables were compared using the chi-square test and the two-sided t test, respectively. Correlations were derived using the Pearson correlation.Results: The percentage of females was 59% and 33.3% in the entropion group and in the ectropion group, respectively. A significant association was found between the gender and type of eyelid malposition (p = 0.015). Exophthalmometry reading was greater in the ectropion group than in the entropion group (17.7 ± 2.5 versus 10.8 ± 3.7 mm, respectively; p < 0.001). There was no significant correlation between axial globe length and exophthalmometry reading. Positive orbital vectors were observed in 87.5% of eyelids with involutional entropion. Negative orbital vectors were observed in 92.3% of eyelids with involutional ectropion (p < 0.001). Patients with negative orbital vectors showed greater axial globe projection than patients with positive orbital vectors (18.0 ± 2.1 versus 10.6 ± 3.5 mm, respectively; p < 0.001).Conclusions: There is an association between orbital vector measurement and involutional entropion and ectropion. Measuring the orbital vector may help predict the development of these lid malpositions.

Magnetic Resonance Imaging of Optic Nerve Traction During Adduction in Primary Open-Angle Glaucoma With Normal Intraocular Pressure.

PurposeWe used magnetic resonance imaging (MRI) to ascertain effects of optic nerve (ON) traction in adduction, a phenomenon proposed as neuropathic in primary open-angle glaucoma (POAG).MethodsSeventeen patients with POAG and maximal IOP ≤ 20 mm Hg, and 31 controls underwent MRI in central gaze and 20° to 30° abduction and adduction. Optic nerve and sheath area centroids permitted computation of midorbital lengths versus minimum paths.ResultsAverage mean deviation (±SEM) was −8.2 ± 1.2 dB in the 15 patients with POAG having interpretable perimetry. In central gaze, ON path length in POAG was significantly more redundant (104.5 ± 0.4% of geometric minimum) than in controls (102.9 ± 0.4%, P = 2.96 × 10−4). In both groups the ON became significantly straighter in adduction (28.6 ± 0.8° in POAG, 26.8 ± 1.1° in controls) than central gaze and abduction. In adduction, the ON in POAG straightened to 102.0% ± 0.2% of minimum path length versus 104.5% ± 0.4% in central gaze (P = 5.7 × 10−7), compared with controls who straightened to 101.6% ± 0.1% from 102.9% ± 0.3% in central gaze (P = 8.7 × 10−6); and globes retracted 0.73 ± 0.09 mm in POAG, but only 0.07 ± 0.08 mm in controls (P = 8.8 × 10−7). Both effects were confirmed in age-matched controls, and remained significant after correction for significant effects of age and axial globe length (P = 0.005).ConclusionsAlthough tethering and elongation of ON and sheath are normal in adduction, adduction is associated with abnormally great globe retraction in POAG without elevated IOP. Traction in adduction may cause mechanical overloading of the ON head and peripapillary sclera, thus contributing to or resulting from the optic neuropathy of glaucoma independent of IOP.

Evaluation of Selected Ophthalmic Diagnostic Tests in Green Iguanas (Iguana iguana)

The objective of this study was to establish reference parameters for different ophthalmic diagnostic tests in green iguanas (Iguana iguana). Median ± semi-interquartile range values of phenol red thread tear test, endodontic absorbent paper point tear test, Schirmer tear test, palpebral fissure length, and intraocular pressure were 3.9 ± 1.7mm/15seconds, 8.5 ± 2.4mm/minutes, 1.0 ± 0.5mm/minutes, 12.4 ± 1.7mm, and 18.0 ± 1.7mm Hg, respectively. Bacterial growth was observed in 18 of 20 conjunctival samples, with a predominance of Gram-positive bacteria (75.8%). Staphylococcus spp. was the most frequently isolated microorganism (39.4%), and a resistance pattern to polymyxin B was demonstrated through antimicrobial susceptibility testing of the bacterial isolates. Median ± semi-interquartile range anterior chamber depth was 1.2 ± 0.2mm and 1.4 ± 0.2mm; vitreous chamber depth, 6.8 ± 0.6mm and 6.8 ± 0.5mm; lens length, 4.4 ± 0.3mm and 4.3 ± 0.3mm; and axial globe length, 12.6 ± 0.8mm and 12.5 ± 0.7mm for the sagittal and dorsal planes, respectively. Conus papillaris length was 6.0 ± 0.3mm and 5.9 ± 0.5mm, whereas the conus papillaris width was measured at 1.1 ± 0.2mm and 1.2 ± 0.2mm, with no difference between the 4.5- and 7.5-hour planes. Hypercellular samples with dense clusters of basaloid and squamous epithelial cells were observed in the conjunctival cytological samples. These results may be helpful for diagnosis and treatment of ocular disorders in green iguanas.

Analysis of factors of variation in lens equatorial length and axial globe length measurements using ultrasonography in dogs with cataract

Summary Purpose To evaluate biological variation of lens equatorial length (LEL) and axial globe length (AL) measurements on B-mode ultrasound and to calculate a formula to predict LEL using AL. Methods Ocular ultrasonography was performed in dogs with cataract, divided into study (n = 40) and control (n = 30) samples. LEL and AL were measured on images obtained at 10 MHz (AL, LEL10) and 35 MHz (LEL35). Breed, sex, weight, age and stage of the cataract were recorded. Dogs were categorized into groups depending on their breed. Effects of these variables on measurements were evaluated. Correlations of AL to LEL10 and LEL35 were assessed; linear regression formulas were calculated then validated. Results No significant effect of age and sex on measurements but significant effects of dogs’ group, weight and stage of the cataract were found. We found strong correlations between AL and LEL10 and between AL and LEL35. Regression formulas were LEL10 = 0.72 × AL − 1.09 and LEL35 = 0.49 × AL + 0.89. Means of the difference between measured and calculated LEL in control sample were 0.28 mm for LEL10 and −0.13 mm for LEL35. Conclusions Ocular measurements were higher in medium/large dogs than in small dogs and in intumescent and hypermature cataract than in mature. Regression formulas to predict LEL might be used with caution.

Intraocular pressure in American Bullfrogs (Rana catesbeiana) measured with rebound and applanation tonometry.

To measure the intraocular pressure (IOP) in normal American Bullfrogs (Rana catesbeiana) with rebound and applanation tonometry and to create calibration curves for both tonometers to determine the actual IOP of bullfrogs. Twenty bullfrogs were evaluated with slip-lamp biomicroscopy, indirect ophthalmoscopy, rebound tonometry, and applanation tonometry. Axial globe length and corneal thickness were measured in the three largest and the three smallest frogs with ultrasonography and optical coherence tomography, respectively. Two frogs were euthanized for direct manometry. The median IOP was 4 mmHg with the rebound tonometer and 16 mmHg with the applanation tonometer. The correlation coefficient (r2 ) between the manometry measurements and the tonometers was 0.95 and 0.91 for the rebound and applanation tonometers, respectively. The corresponding equations were y = 0.331x + 0.558 for the rebound tonometer and y = 0.675x + 1.907 for the applanation tonometer. The median axial globe length was 0.94 cm. The median corneal thickness was 0.093 mm. The rebound tonometer is the preferable tonometer for American Bullfrogs. Neither tonometer produced IOP readings that matched the manometer. The rebound tonometer was more precise and it was faster and easier to use.

Ophthalmic diagnostic testing and examination findings in a colony of captive brown pelicans (Pelecanus occidentalis).

To establish reference values and report ophthalmic examination findings in a colony of captive brown pelicans (Pelecanus occidentalis). Descriptive study. Sixty-three captive brown pelicans in Florida were examined. A complete ophthalmic examination including Schirmer tear test (STT), applanation tonometry, fluorescein stain, biomicroscopy, and direct and indirect ophthalmoscopy was performed. A-scan ultrasonography was performed to measure axial globe length (AGL), anterior chamber depth (ACD), lens thickness, and vitreal chamber length. Fifty-two adults and 11 juvenile pelicans with an age range of 4months to 38years were evaluated. Twenty-nine pelicans (46%) had a normal ocular examination. Mean STT in normal pelicans was 5.45±1.88mm/min. Mean intraocular pressure (IOP) in normal pelicans was 10.86±1.61mmHg. One pelican was fluorescein positive unilaterally. Mean AGL was 20.70±0.62mm. Mean ACD was 3.38±0.19mm. Mean axial lens diameter (ALD) was 5.19±0.23mm. Mean vitreal chamber depth (VCD) was 12.15±0.53mm. Twenty-three pelicans (36.51%) had cataracts, 17 pelicans (26.98%) had vitreal degeneration, 18 pelicans (28.57%) had corneal disease, and seven pelicans (11.11%) had evidence of significant ocular trauma, which included collapsed anterior chamber or lens luxation. To the author's knowledge, this is the first report of normal ophthalmic parameters and the incidence and type of ocular disease in a captive flock of brown pelicans. This information may aid in the diagnosis and treatment of brown pelicans with ocular disease.

Ophthalmic Diagnostic Tests in Parrots (Amazona amazonica) and (Amazona aestiva)

The aim of this study was to evaluate the ophthalmic parameters of Amazona amazonica and Amazona aestiva maintained in captivity in Salvador, Bahia, Brazil. Median ± S-IQR phenol red thread test was 21.9 ± 2.3mm/15s and 12.6 ± 2.6mm/15s, endodontic absorbent paper point tear test 14.9 ± 1.6mm/min and 13.1 ± 1.4mm/min, and intraocular pressure 8.3 ± 1.1mmHg and 9.7 ± 1.7mmHg for A. amazonica and A. aestiva, respectively. Corneal sensitivity was 0.50 ± 0.25cm for A. amazonica and 1.00 ± 0.00cm for A. aestiva. The mean ultrasonographic dimensions measured were anterior chamber depths of 2.0 ± 0.1mm and 2.0 ± 0.1mm, lens axial lengths of 3.6 ± 0.0mm and 3.6 ± 0.1mm, vitreous chamber depths of 7.9 ± 0.4mm and 8.0 ± 0.2mm, axial globe lengths of 13.5 ± 0.4mm and 13.6 ± 0.1mm, and pecten oculi lengths of 6.4 ± 0.5 and 6.3 ± 0.3mm for A. amazonica and A. aestiva, respectively. The development of complementary knowledge about the ocular morphology and histology of these parrot species can be used to contribute to advances in the ophthalmology of wild birds.

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.

Ophthalmic Diagnostic Tests and Ocular Findings in a Flock of Captive American Flamingos ( Phoenicopterus ruber ruber).

Seventeen adult captive American flamingos ( Phoenicopterus ruber ruber) (34 eyes) underwent a complete ocular examination, including assessment of menace response, pupillary light reflexes, dazzle reflex, palpebral and corneal reflexes, fluorescein staining, slit-lamp biomicroscopy, and direct ophthalmoscopy. Birds were randomly assigned to one of 2 groups for tear production and intraocular pressure measurements. Tear production was measured by modified Schirmer tear test I (n = 9 birds) or phenol red thread test (n = 8 birds), and intraocular pressure was measured indirectly by applanation (Tonopen-XL) (n = 9 birds) or rebound (TonoVet) (n = 8 birds) tonometry. Conjunctival swab samples were taken from one randomly selected eye of all 17 birds to identify surface ocular microbial flora via aerobic bacterial culture. Additionally, 3 of the 17 birds were anesthetized for bilateral B-mode ocular ultrasonography examination to obtain axial globe measurements. Results showed that the menace response and dazzle reflex were absent in all birds. Sixteen of the 17 birds were free of significant ocular disease; a small cataract and pigment on the anterior lens capsule were noted in one eye of one bird. Mean ± SD tear production was 12.3 ± 4.5 mm/min (range, 4-20 mm/min) for modified Schirmer tear test I and 24.2 ± 4.4 mm/15 s (range, 14-30 mm/15 s) for phenol red thread test. Modified Schirmer tear test I measurements were significantly lower than phenol red thread measurements (P < .001). Mean intraocular pressure was 16.1 ± 4.2 mm Hg (range, 7-22 mm Hg) for Tonopen and 9.5 ± 1.7 mm Hg (range, 7-13 mm Hg) for TonoVet. Tonopen measurements were significantly higher than TonoVet measurements (P < .001). An Enterococcus species (9/17 eyes; 53%) and a gram-positive coccus (7/17 eyes; 41%) were the bacteria most commonly isolated from conjunctival swab samples. Mean B-mode ultrasonographic globe measurements of 6 eyes (3 birds) were axial globe length, 13.8 ± 0.16 mm; anterior chamber depth, 1.75 ± 0.05 mm; lens thickness, 4.6 ± 0.06 mm; vitreous body depth, 6.95 ± 0.10 mm; and pecten dimensions, 5.1 ± 0.38 mm length, 2.2 ± 0.14 mm width. In summary, the prevalence of ocular lesions was low in this population of captive American flamingos. Results obtained from 2 types of tear and intraocular pressure measurement tests were significantly different, indicating that a single type of each diagnostic test should be consistently used. A modification of the standard Schirmer tear test or use of phenol red thread test is recommended due to the small flamingo eye.

Axial Globe Length in Congenital Ptosis.

To compare axial globe length between affected and unaffected sides in patients with unilateral congenital ptosis. This prospective observational study included 37 patients (age range: 7 months to 58 years). The axial globe length, margin reflex distance-1 (MRD-1), and refractive power were measured. The axial globe length difference was calculated by subtracting the axial globe length on the unaffected side from that of the affected side. The relationships among axial globe length differences, MRD-1 on the affected sides, and patient ages were analyzed using multiple regression analysis. No significant differences were found in the axial globe length between sides (P = .677). The axial globe length difference was 0.17 ± 0.30 mm (mean ± standard deviation), and two patients (5.4%), aged 32 to 57 years, showed axial globe length more than 0.67 mm longer (corresponding to a refractive power of 2 diopters) on the affected side compared to the unaffected side. The multiple regression model between axial globe length difference, patient age, and MRD-1 on the affected sides was less appropriate (YAGL = 0.003XAGE-0.048XMRD-1 +0.112; r = 0.338; adjusted r2 = 0.062; P = .127). The cylindrical power was greater on the affected side (P = .046), although the spherical power was not different between sides (P = .657). No significant difference was identified in the axial globe length between sides, and only 5% of non-pediatric patients showed an axial globe length more than 0.67 mm longer on the affected side. Congenital ptosis may have little effect on axial globe length elongation, and the risk of axial myopia-induced anisometropic amblyopia may be low in patients with unilateral congenital ptosis.