Comparison between ocular biometry parameters in patients with unilateral congenital glaucoma

Purpose: To compare the axial length (AL) and corneal diameter between glaucomatous eye (GE) and fellow normal eye (NE) in patients with unilateral congenital glaucoma and to obtain a normative database for ocular growth among Indian children below 3 years of age. Methods: Retrospective longitudinal study. Patients who had a follow?up of 3 years from diagnosis with ocular biometry parameters being recorded at least thrice (once a year) and fellow eye being normal were included. Data collected were age, gender, intraocular pressure (IOP), AL, corneal diameter, optic disc findings, diagnosis, and surgery details. Results: Eleven patients were analyzed. All GE underwent combined trabeculotomy with trabeculectomy. Mean (SD) baseline IOP, AL, and corneal diameter were 17.1 (6.7) mmHg, 18.9 (1.1) mm and 12 (0.91) mm in GE, and 11.1 (3.8) mmHg, 17.8 (0.44) mm, and 10.5 (0.58) mm in NE, respectively. Increase in AL was 3.1 mm in the first year followed by 0.6 mm in second year and 0.4 mm in third year in GE compared to 2.6, 0.6, and 0.5 mm in NE, respectively. Corneal diameter increased by 1.1 mm in GE in the first year and remained stable thereafter compared to 0.7 mm in first year followed by 0.3 mm in second year and stable thereafter in NE. The percentage of success was 73% at 3 years. Conclusion: Axial length and corneal diameter were higher in GE than NE at all?time points. With prompt intervention, the growth curve of the GE was made parallel to that of NE.

Correlation between ciliary sulcus diameter and corneal diameter of patients with low to moderate myopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To determine the correlation among horizontal ciliary sulcus(HCS)diameter, vertical ciliary sulcus(VCS)diameter and corneal diameter in different anterior chamber depth(ACD)levels from patients with low to moderate myopia.METHODS: Retrospective study. A total of 78 patients(129 eyes)with low to moderate myopia who had preoperative examination of implantable contact lens(ICL)implantation in Shanghai Bright Eye Hospital from April 2021 to April 2022 were included. HCS, VCS and white to white(WTW)were measured and compared. Patients were divided into shallow ACD group(2.8 mm ≤ ACD ≤3.2 mm), medium ACD group(3.2 mm < ACD ≤3.4 mm)and deep ACD group(ACD > 3.4 mm)based on the ACD obtained by Pentacam. The HCS, VCS and WTW within and among groups were compared, and the correlation of WTW, HCS and VCS among each group was analyzed by Pearson and linear regression equation.RESULTS: There was no statistical difference in WTW and HCS overall and in groups with different ACD(P>0.05), while there was difference between VCS and both HCS and WTW(P<0.01). The WTW had a correlation with both HCS and VCS in each group, while correlation between WTW and VCS was weak in the deep ACD group(r=0.470, R2=0.221, P<0.01). Furthermore, the WTW, HCS and VCS in the shallow ACD group were statistically different from those in the medium and deep ACD groups(P<0.01).CONCLUSION: The WTW was suggested predicting HCS rather than perfectly replacing HCS before patients had the ICL operation among patients with low to moderate myopia. The predictability of VCS would decline as the ACD depth increasing, predicting VCS by WTW was not recommended.

Clinical study on the diagnosis of early keratoconus based on ocular morphological parameters with different corneal diameters / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the diagnostic value of ocular morphological parameters under different corneal diameters for early keratoconus.METHODS: A retrospective case-control study. A total of 201 patients(201 eyes)who were treated in our hospital from January 2019 to March 2022 were included. They were divided into 135 cases(135 eyes)in the control group(patients with history of refractive error)and 66 cases(66 eyes)in the subclinical keratoconus group. The Pentacam anterior segment analyzer was used to determine the horizontal central curvature of corneal posterior surface(Kf), posterior vertical central curvature of corneal posterior surface(Ks), average curvature of corneal posterior surface(Km), Posterior I-S ratio, corneal posterior surface height after the thinnest point(PE at the thinnest point), maximum posterior elevation from best fit sphere(MPE from BFS), maximum posterior elevation from best fit toric ellipsoid(MPE from BFTE), posterior asphericity asymmetry index(AAI), thinnest point thickness of the cornea(TCT), central corneal thickness(CCT), depressed corneal thickness(DCT), pachymetric progression index average(PPIavg), Ambrósio relational thickness maximum(ARTmax)and Belin D value. The differences of each parameter between the two groups were analyzed. Receiver operating characteristic(ROC)curves were analyzed to determine the best diagnosis point. The control group was further divided into groups according to the corneal diameter: corneal diameter ≤11.0mm, 11.1mm≤ corneal diameter ≤11.5mm, 11.6mm≤ corneal diameter ≤12.0mm, corneal diameter ≥12.1mm. The differences of each parameter among these groups were compared. Pearson correlation analysis was used to analyze the correlation between corneal diameter and other parameters.RESULTS: There were significant differences in posterior I-S ratio, PE at the thinnest point, MPE from BFS, MPE from BFTE, posterior AAI, TCT, DCT, PPIavg, ARTmax, Belin D value between the subclinical keratoconus group and the control group(P&#x0026;#x003C;0.05). Sensitive index of Pentacam to diagnosis subclinical keratoconus were Belin D value, posterior I-S ratio, PPIavg, posterior AAI and MPE from BFTE(AUC≥0.9). In the control group, there was no significant difference in posterior I-S ratio, MPE from BFTE, posterior AAI, TCT, CCT, and DCT among different corneal diameter groups (P&#x0026;#x003E;0.05), and there was no significant correlation with corneal diameter(all P&#x0026;#x003E;0.05).CONCLUSION: The Belin D value, posterior I-S ratio, PPIavg, posterior AAI, MPE from BFTE obtained by Pentacam are sensitive indicators for the diagnosis of early keratoconus, among which posterior I-S ratio, posterior AAI, MPE from BFTE are less affected by corneal diameter. They play an important role in the early diagnosis of keratoconus under different corneal diameters.

Comparación de biometría ocular entre adultos jóvenes chinos y cubanos / Comparison of ocular biometry between chinese and cuban young adults

Objetivo: Comparar la biometría ocular entre adultos jóvenes chinos y cubanos pertenecientes al sector salud. Métodos: Estudio observacional descriptivo de corte transversal en 30 chinos y 30 cubanos, residentes de las diferentes especialidades médicas, que acudieron al Instituto Cubano de Oftalmología "Ramón Pando Ferrer" entre septiembre de 2016 y septiembre de 2017. Las variables estudiadas fueron: longitud axial, profundidad de cámara anterior, y diámetro corneal horizontal. Se realizó biometría de no contacto con IOLMaster 500 (Carl Zeiss) en ambos ojos. Resultados: La edad media fue 24,9 años y 25,9 años en cubanos y chinos respetivamente. Los resultados biométricos promedio de ambos ojos para cubanos/chinos fueron: longitud axial 24,10 mm/24,60 mm; amplitud de cámara anterior 3,56 mm/3,46 mm; y diámetro corneal horizontal 11,80 mm/11,60 mm, sin diferencias estadísticamente significativas. El 60 de los ojos chinos fueron largos mientras que en los cubanos fue el 45 . Se reportaron dos ojos chinos con cámara anterior estrecha y el diámetro corneal horizontal fue normal en el 100 por ciento. Conclusiones: Los chinos exhibieron ojos de mayor longitud axial, menor amplitud de cámara anterior y menor diámetro corneal horizontal que los cubanos aunque las diferencias no fueron estadísticamente significativas.(AU)

Objective: To compare ocular biometry between Chinese and Cuban young adults belonging to the health sector. Methods: Descriptive observational cross-sectional study in 30 Chinese and 30 Cubans, residents of different medical specialties, who attended the Cuban Institute of Ophthalmology "Ramón Pando Ferrer" between September 2016 and September 2017. The variables studied were: axial length, anterior chamber depth, and horizontal corneal diameter. Non-contact biometry was performed with IOLMaster 500 (Carl Zeiss) in both eyes. Results: The average age was 24.9 years and 25.9 years in Cuban and Chinese patients respectively. The average biometric results of both eyes for Cuban/Chinese eyes were: axial length 24.10 mm/24.60 mm; anterior chamber width 3.56 mm/3.46 mm; and horizontal corneal diameter 11.80 mm/11.60 mm, with no statistically significant differences. Sixty percent of the Chinese eyes were long, while 45 percent of the Cuban eyes were long. Two Chinese eyes were reported with narrow anterior chamber and horizontal corneal diameter was normal in a 100 percent of them. Conclusions: Chinese exhibited eyes of greater axial length, smaller anterior chamber width and smaller horizontal corneal diameter than Cubans although the differences were not statistically significant(AU)

Validating the use of U-tool as a novel method for measuring the corneal diameter in infants screened for congenital glaucoma

Purpose: The Castroviejo caliper is routinely used for measuring the corneal diameter in patients with primary congenital glaucoma, but needs an examination under anesthesia (EUA) or sedation. A simple U?shaped tool was devised to aid in the estimation of the corneal diameters of patients in settings where an ophthalmic caliper is not available or EUA is not feasible. Methods: Infants presenting to the congenital glaucoma clinic posted for EUA were recruited. The demographic details of the patients such as age, sex, and diagnosis were noted. A simple U?shaped tool was devised using three Schirmer strips or a printable ruler. Before the patient underwent a EUA, the corneal diameters were measured using the U?tool. During EUA, corneal diameters were measured using the Castroviejo caliper. Results: The mean age of infants was 6.7 ± 3.39 months (R = 1–12). The mean corneal diameter measured using the U?tool was 13.29 ± 1.33 mm and with Castroviejo caliper was 13.18 ± 1.39 mm. The difference between the corneal diameters measured using the two techniques was ?0.114 mm with the Bland–Altman plot 95% Limits of agreement (LoA) from ?0.965 to 0.737 mm. Corneal diameters measured with both instruments had a good correlation (Pearson’s correlation coefficient = 0.95, P < 0.001). Conclusion: U?tool can be used for screening congenital glaucoma by first?contact physicians or optometrists. It can also be used by ophthalmologists when EUA is delayed

Central corneal thickness and corneal diameter in preterm and term newborns and preterm neonates at term

Purpose: To record central corneal thickness and corneal diameter in preterm and term newborns within first week of their birth and in preterm neonates at term age. Methods: Babies born at ?34 weeks of gestation period (n = 100), term babies who have a gestation period of >37 weeks (n = 100) and preterm neonates at term age (38-42 weeks) who were born at ?34 weeks (n = 100) were included in this hospital based observational descriptive study. Corneal diameter was taken by Castroviejo Calipers. Central corneal thickness was measured using portable ultrasonic pachymeter (Pachette 3). Refractive status of the eyes was measured using streak Wellch Allyn retinoscope under cyclopentolate cycloplegia. Results: Measure of central corneal thickness and corneal diameter in preterm newborns was found to be 633.5 ± 2.8 ?m and 8.1 ± 0.6 mm, in full term newborns it was 555.1 ± 2.7 ?m and 9.5 ± 0.6 mm, and in preterm neonates at term age, it was 563.5 ± 2.5 ?m and 9.6 ± 0.5 mm, respectively. Mean central corneal thickness was found to be more in preterm newborns 633.5 um then term newborns 555.1 um and the difference was statistically significant (P =0.001). Mean corneal diameter was found to be maximum (9.6 mm) in preterm neonates at term age. Conclusion: Preterm babies have thick corneas and small corneal diameters. This study is useful with respect to the analysis of glaucoma in children and using preterm corneas as donor corneas in penetrating keratoplasty.

Contrastive analysis of corneal horizontal diameter measurement by five instruments / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To analyze the correlation and consistency of five corneal diameter measurements.<p>METHODS: Totally 25 cases(50 eyes)who underwent ICL implantation in West China Hospital. The preoperative horizontal corneal diameter was measured using measuring caliper, SIRIUS anterior eye assay system, IOL Master500, anterior segment OCT and UBM. <p>RESULTS: The mean WTW distances were 11.54±0.30 mm as obtained with measuring caliper, 11.77±0.33mm with SIRIUS anterior eye assay system, 11.98±0.33mm with IOL Master500, 11.63±0.35mm with anterior segment OCT and 11.53±0.34mm with UBM. No statistical difference was found between measuring caliper and UBM, measuring caliper and anterior segment OCT, UBM and anterior segment OCT. The linear correlation analysis found significant correlation between the measurements of the five measurements. The Bland-Altman analysis for the measuring caliper and SIRIUS, measuring caliper and UBM, measuring caliper and anterior segment OCT found that the absolute values of 95% LOA upper and lower limits were less than 0.5mm.<p>CONCLUSION: The results of the four kinds of corneal horizontal diameter measurements can be interchanged including SIRIUS, UBM, anterior segment OCT and measuring caliper. IOL Master500 results are the largest, that cannot be used as a diagnostic basis for measuring the size of corneal horizontal diameter. The results of other measurement equipment should be combined with clinical practice.

Study on the correlation between horizontal corneal diameter and anterior chamber diameter and ciliary sulcus diameter / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the correlation between horizontal corneal diameter(WTW), horizontal anterior chamber diameter(HACD)and horizontal ciliary sulcus diameter(S-S). <p>METHODS: A total of 62 cases(115 eyes)with high myopia were collected from those who were examined in our hospital from August 2015 to August 2016. Their WTW and HACD were measured with SIRIUS, while S-S was measured with UBM, and the results were compared and analyzed. <p>RESULTS: In all patients, WTW was 11.91±0.37mm, HACD was 12.45±0.43mm, S-S was 11.78±0.46mm. There was negative correlation between HACD or S-S and age(<i>r</i>=-0.423 and <i>r</i>=-0.386 respectively, all <i>P</i><0.05). Correlation comparison with central anterior chamber depth(ACD)showed in group with ACD≤3.5mm, WTW and HACD were related with S-S; while in group with ACD>3.5mm, there was no significant correlation between WTW or HACD and S-S. <p>CONCLUSION: 1)WTW and S-S has better correlation, but due to the influence of age and anterior chamber depth, S-S is recommended to be measured with reference to the UBM to determine ICL when the patient is equal to or over 40 years old or with ACD>3.5mm; 2)SIRIUS Anterior Segment System is safe, simple and repeatability in measuring WTW and HACD.

Corneal parameters and their correlations with refractive error, axial length, anterior chamber depth and lens thickness in black South Africans / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To establish profiles of corneal diameter(CD), curvature(ACC), corneal central thickness(CCT)and investigate their correlations with refractive errors' spherical equivalent(SE), axial length(AL), anterior chamber depth(ACD)and crystalline lens thickness(LT)in black South Africans with healthy eyes. We also investigated the intercorrelation among the three corneal parameters.<p>METHODS:Eyes of six hundred subjects that included 305 males and 295 females(mean age: 28.15±13.1y, range: 10-66y)underwent a complete ophthalmic examination including refraction, slit lamp and ophthalmoscopy. CD and ACC were measured using the Oculus Keratograph 4(OCULUS Optikgeräte GmbH), and the CCT was measured with the iVue-100(Optovue, Inc.)optical coherence tomography. Refractive errors were assessed with the Nidek AR-310A auto-refractor and then subjective refraction. The AL, ACD and LT were measured with the Nidek US-500 A-scan ultrasound device. <p>RESULTS:There are no statistically significant between the parameters of the right and left eyes assessed, and therefore only the results of the right eyes are presented here. The mean corneal parameter values were: CD=11.77±0.32 mm(range=10.30-13.70 mm), ACC=7.88±0.29 mm(range=7.13-8.88 mm)and CCT=493.05±33.2 μm(range=412-590 μm). CD did not correlate with SE(r=0.05, <i>P</i>=0.24). However, CD was correlated significantly with AL(<i>r</i>=0.58, <i>P</i>=0.00)and ACD(<i>r</i>=0.63, <i>P</i>=0.00)but inversely correlated with LT(<i>r</i>=-0.40, <i>P</i>=0.00). There was no significant correlations between ACC and SE(<i>r</i>=-0.03, <i>P</i>=0.48). ACC correlated positively with AL(<i>r</i>=0.40, <i>P</i>=0.00). There were no significant correlations between ACC and ACD(<i>r</i>=0.04, <i>P</i>=0.56), and LT(<i>r</i>=-0.03, <i>P</i>=0.88). Also, there was no correlation between CCT and other ocular dimensions assessed. However, correlations among corneal parameters showed that CD correlated with ACC(<i>r</i>=0.71, <i>P</i>=0.00)and CCT(<i>r</i>=-0.68, <i>P</i>=0.00).<p>CONCLUSION:While CD correlated with AL, ACD and LT, the ACC correlated with AL. CCT did not correlate with any of the metrics studied here, suggesting that it is an independent factor unrelated to other ocular dimensions. Among corneal parameters, CD correlated with ACC and CCT.

Effects of Ocular Parameters on Diameter of Well-fitted Rigid Gas Permeable Lens in Koreans

PURPOSE: To compare the differences of parameters of 9.3 mm and 8.8 mm rigid gas permeable lenses (RGP lenses) that were prescribed by trial lens fitting. METHODS: Ninety-three eyes of 49 patients were prescribed RGP contact lenses (YK spherical lens, Lucid Korea, Bonghwa, Korea) by a single ophthalmologist at the same hospital. We analyzed the differences of parameters of 9.3 mm and 8.8 mm rigid gas permeable lenses (RGP lenses) that were prescribed by trial lens fitting. Steep keratometric value (Ks), flat keratometric value (Kf), and corneal astigmatism (Kast) were measured by keratometer. Simulated steep keratometric value (Sim Ks), simulated flat keratometric value (Sim Kf), simulated corneal astigmatism (Sim Kast), white to white corneal diameter (WTW), and eccentricity were measured by corneal topography. We also analyzed the differences of back optic zone radius (BOZR) and lens power between the two groups. RESULTS: In this study, 40 eyes wearing 8.8 mm lenses and 53 eyes wearing 9.3 mm lenses were included. Keratometric value and eccentricity were significantly higher in the 8.8 mm lens group, while WTW and BOZR were significantly lower. Corneal astigmatism (Kast, Sim Kast) and lens power were not significantly different between the groups. CONCLUSIONS: RGP lenses with a smaller diameter were likely to be prescribed to patients with higher keratometric value, higher eccentricity, and shorter WTW, and the average BOZR of the prescribed RGP lenses with a smaller diameter was likely to be steeper.

Comparison of Eyemetrics and Orbscan automated method to determine horizontal corneal diameter.

Purpose: To compare horizontal corneal diameter measurements using the Orbscan Eyemetrics function and Orbscan corneal topographer. Materials and Methods: Seventy-three eyes of 37 patients were included in the study. In all cases, the automated white-to-white (WTW) measurements were obtained using Orbscan by two observers. Using the Eyemetrics function, the WTW was measured manually by the same observers from limbus to limbus using the digital caliper passing through the five point corneal reflections on the Orbscan real image. The data was analyzed using SPSS software for correlation, reliability and inter-rater repeatability. Results: The mean horizontal corneal diameter was 11.74 ± 0.32mm (SD) with the Orbscan and 11.92 ± 0.33mm (SD) with Eyemetrics Software-based measurement. A good positive correlation (Spearman r = 0.720, P = 0.026) was found between these two measurements. The coefficient of inter-rater repeatability was 0.89 for the Orbscan and 0.94 for the Eyemetrics software measurements on the anterior segment images. The Bland and Altman analysis showed large limits of agreement between Orbscan WTW and Eyemetrics WTW measurements. The intra-session repeatability scores for repeat measurements for the Orbscan WTW and Eyemetrics measurements were good. Conclusion: Eyemetrics can be used to measure WTW and the Eyemetrics measured WTW was longer than the WTW measured by Orbscan.

The Correlations Between Landmark of Inferior Oblique Muscle Recession and Adjacent Globe Structures

PURPOSE: This study aimed to find out whether there are relationships among anatomic characteristics of inferior oblique muscle insertion, corneal diameter, axial length and inferior oblique recession landmark. METHODS: Thirty-one Korean cadaver orbits were dissected to expose the full length of extraocular muscles and sclera, and then we measured the length from the recession landmark of inferior oblique to the lateral edge of insertion of inferior rectus and to the inferior edge of insertion of lateral rectus. RESULTS: The mean of angles between the inferior oblique muscle insertion and lateral rectus direction is 27.9+/-9.0degrees and the range is from 15 degrees to 50 degrees . There is a statistically significant correlation between cord length of 8 mm recession landmark of inferior oblique and angles of inferior oblique insertion with lateral rectus direction. We divided the shapes of inferior oblique insertion into straight and convexed curves. Twelve insertions are straight and thirteen insertions are curved. There is no statistically significant correlation between shape of inferior oblique insertion and cord length from recession landmark. In corneal diameter and axial length, we found correlations with cord length of 8 mm and 10 mm recession landmark of inferior oblique. CONCLUSIONS: We conclud that there are some correlations among anatomic characteristics, axial length and corneal diameter with recession landmark of inferior oblique.

IOP & Corneal Diameter in Premature Infants

Premature infants may have underdevelopment of multiple organs including ocular structures.Sixty one premature infants of thirty seven weeks-old or younger were examed to note the correlation of intraocular pressure andcorneal diameter with gestational age and birth weight. Following topical anesthesia, intraocular pressure was measured with Tonopen II tonometer and the corneal diameter with caliper.The fundus was examed for the presence of risk factors for retinopathy of prematurity. Average gestational age of the subjects was 30.2 weeks (26~37 weeks), and birth weight was 1419 g (677~3691 g).Thirty five subjects had experienced oxygen therapy, and eleven patients were found to have any stage of retinopathy of prematurity. Average intraocular pressure was 10.8 +/-2.3 mmHg (mean +/-standard deviation), corneal diameter was 8.8 +/-0.5 mm.No significant correlation was found between intraocular pressure or corneal diameter and gestational age or birth weight.The presence of retinopathy of prematurity did not seem to influence the intraocular pressure and corneal diameter. Our results suggested that the growth in uterus did not seem to affect intraocular pressure or corneal diameter in gestational age of 26 to 37 weeks. These normative values may aid ophthalmologists in assesing intraocular pressure and corneal diameter in premature infants.

Intraocular Pressure, Corneal Diameter and C/D Ratio in Normal Newborns

Eight-two eyes of 41 normal newborn were examined at their second day of life to determine intraocular pressure with Tonopen and horizontal corneal diameter with caliper and Cup/Disc(C/D) ratio with direct ophthalmoscope under chloral hydrate sedation. It was 13.0 +/- 3.4mmHg, 10.0 +/- 0.4 and 0.3 +/- 0.1, respectively. These values will aid the ophthalmologist in the diagnosis and management of congenital glaucoma.