Comparison of corneal and lens density measurements obtained by Pentacam and CASIA2 in myopes.

PURPOSE: To investigate the agreement between Pentacam and CASIA2 in the evaluation of corneal densities (CDs) and lens densities (LDs) in myopes. METHODS: Fifty-three patients (106 eyes) underwent comprehensive ophthalmologic examinations. CDs and LDs were measured using Pentacam and CASIA2, respectively, based on the grayscale percentage of the obtained images. Agreement between Pentacam and CASIA2 was evaluated using the consistency intraclass correlation coefficient (ICC) and represented using Bland-Altman plots. RESULTS: Compared to Pentacam, CASIA2 showed significantly higher CD and LD values in all measured zones. The ICC of the average CD and LD measured by the Pentacam and CASIA2 were 0.726 and 0.757, respectively. The ICC values of all corneal zones and lenses were above 0.7, except for the measurement of the cornea in the 0-2 mm zone (0.455), suggesting good consistency between the two devices, whose results were of different levels of linear correlation. Bland-Altman plots showed mean percentages of 3.93% for the points falling outside the limits of agreement among the densitometry results. The ICCs in different age groups were similar, but the agreement was poorer in the high myopia group (low and moderate myopia, CD: 0.739, LD: 0.753; high myopia, CD: 0.621, LD: 0.760). CONCLUSIONS: CASIA2 demonstrated good consistency with Pentacam in the measurement of CD and LD, except for measurement of CD in the central cornea and in high myopia. Despite difference in the numerical results compared with Pentacam, which made the two devices uninterchangeable, CASIA2 provides a reliable alternative densitometric measurement method.

Long-term changes in crystalline lens transparency after accelerated transepithelial corneal cross-linking in patients with keratoconus.

PURPOSE: To investigate the long-term clinical outcomes and changes in crystalline lens transparency after accelerated (45 mW/cm2) transepithelial corneal cross-linking (ATE-CXL) using the Pentacam imaging system in patients with progressive keratoconus. METHODS: The study prospectively included 44 keratoconus eyes of 40 patients (mean age: 24.39 ± 5.61 years) who underwent ATE-CXL. The examinations, including assessment of uncorrected distance visual acuity, corrected distance visual acuity, corneal topography, and corneal endothelial cell density count, were conducted preoperatively and 1 month, 3 months, 6 months, 1 year, and 5 years postoperatively. Measurement of crystalline lens density using Pentacam images was also performed pre- and postoperatively. RESULTS: All surgeries were uneventful with no postoperative complications. All keratometry values and corneal thickness remained stable during the 5-year follow-up period (all p > 0.05). There were no significant differences in corneal endothelial cell density count, visual acuity, and anterior average lens density in the 0.5-, 1.0-, and 1.5-mm depth zones during the 5-year follow-up period compared with the preoperative values (all p > 0.05). CONCLUSION: The results of this study suggest that ATE-CXL at 45 mW/cm2 is safe and effective for the treatment of progressive keratoconus in terms of both crystalline lens density and endothelial cell density.

Age-related changes of lens thickness and density in different age phases.

AIM: To explore the changes in lens thickness and density with age. METHODS: A Chinese population-based retrospective study was performed. A total of 497 individuals (490 right eyes and 495 left eyes), ranging from 3 to 69 years old were included. Lens images obtained from IOL Master 700 were used to measure lens thickness and density. Piecewise regression model was chosen to illustrate the relationship of lens thickness and density with age. RESULTS: The proportion of people aged 3-18, 19-40, over 40 was 38.6%, 50.9% and 10.5% respectively. The whole lens thickness decreased with age during the first 7 years of life, kept stable from 8 to 16 years old, and then increased at the rate of about 27 µm per year. The thickness of the lens cortex and nucleus tended to decrease first and then increase with age, which was dependent on age stages. The whole lens density also decreased with age until 7 years old. The increasing rate of lens density was different in different age groups. The whole lens density increased rapidly from 7 to 22 years old and slowed down after 22 years old. Similarly, the changing tendency of lens cortical and nuclear density differed in different age phases. CONCLUSION: Both lens thickness and density are significantly associated with age, whereas they do not change linearly with age. Moreover, it is necessary to increase the population over 40 years old and conduct further research.

Cataract Grading in Pure Senile Cataracts: Pentacam versus LOCS III.

Purpose: To determine the diagnostic accuracy of Pentacam Cataract Grading Scale (PCGS) versus the Lens Opacities Classification System (LOCS III) in scaling pure age-related cataract. Methods: Between April 2016 and May 2017, eyes of 281 patients were evaluated for grading of lens opacity. We used LOCS III and PCGS. Patients with pure age-related cataract with no previous history of eye surgery, eye trauma, or chronic systemic disease between 50 and 95 years of age were included. The examination of the patients was done, using slit lamp and LOCS III grading chart. The second examination was done a week later, using Oculus Pentacam. Next, we graded them using a PNS grading score. Spearman's rank correlation and a Bland-Altman Plot were implemented for analysis using MedCalc 14. 8.1. P < O.05 was considered as statistically significant. Results: Three hundred eyes were examined. Of them, 189 patients were male, and patients between 70 to 80 years old were the most common group. The correlation between grades of two methods was 0.47 (P < 0.001). Results of the Bland-Altman plot showed a moderate alignment between the two methods. Conclusion: The association between LOCSIII and PCGS is not so favorable, however, it is an economical and effective method to assess lens opacities is LOCSIII. PCGS can be used in early diagnosis. For a definitive diagnosis and appropriate therapeutic intervention, an ophthalmological examination is needed.

Association of lens density quantified by IOLMaster 700 with lenticular myopia in nuclear cataract.

PURPOSE: To explore the associated ocular parameters with lenticular myopia and assess the correlation between lens density and myopic shift. METHODS: This retrospective cross-sectional study enrolled 50 patients with lenticular high myopia as the study group and 85 cases as the validation group. Lens density was obtained through swept-source optical coherence tomography (SS-OCT, IOLMaster 700) and measured by Image J software. Linear regression analysis and correlation analysis were applied to study the association between lenticular myopia and ocular variables. Receiver operating characteristic curves and calibration charts were plotted for nuclear density (ND) in identifying lenticular high myopia. RESULTS: Both ND and lens thickness were discovered to be associated with spherical equivalent refraction and lens power (p < 0.05); yet, only ND was significantly correlated with lenticular myopia, as the difference of nuclear density (NDdiff) between the lenticular myopic eye and the fellow eye was significantly correlated with the interocular difference of spherical equivalent refraction (SERdiff, r = - 0.752, p < 0.001) and the interocular difference of lens power (LPdiff, r = 0.834, p < 0.001). The ND is a good metric for diagnosing lenticular high myopia, with the area under curve (AUC) being 0.898 (0.821-0.949) and the cut-off value being 98.88 pixel units. The accuracy of the cut-off value in the validation group was 82.35%. CONCLUSIONS: Average ND quantified by IOLMaster 700 is not only associated with lenticular myopia but is a suitable metric for predicting the amount of myopic shift.

Evaluation of anterior segment parameters with Pentacam in children with poorly-controlled type 1 Diabetes Mellitus without diabetic retinopathy.

PURPOSE: To determine the effect of abnormal glucose metabolism on the cornea, lens, anterior chamber volume (ACV), and anterior chamber depth (ACD) in children with poorly-controlled type 1 diabetes mellitus (DM) without diabetic retinopathy (DR). METHODS: After the complete ophthalmologic examination of children with poorly-controlled (glycosylated hemoglobin [HbA1c] >7.0 %) type 1 DM without DR and age-matched healthy subjects (control group), the central corneal thickness (CCT), keratometry (K) values (Kmean front and back, and Kmax), radius (R) values (Rmin front and back), corneal volume (CV), ACD, ACV, pupil diameter, mean lens density (MLD), lens density standard deviation (LD SD), and maximum lens density (LD max) were measured using Pentacam High Resolution. Endothelial cell density was measured using a specular microscope. The results were assessed and compared between the two groups. RESULTS: There were 60 patients (38 boys and 22 girls) in the DM group and 30 (14 boys, 16 girls) in the control group. There were considerable differences between the groups in terms of CCT, CV, ACD, MLD, LD SD and LD max, and Kmean back. Further, there was a positive correlation between HbA1c and MLD, LD SD, CV, and CCT in patients with DM. CONCLUSION: The results of our study demonstrate that poorly-controlled type 1 DM without DR affects the cornea, ACD, and LD based on anterior segment measurements taken with a Scheimpflug camera. CCT, CV, LD SD, and MLD values may be parameters that can be used to follow-up patients with type 1 DM.

Changes in anterior lens density after Implantable Collamer Lens V4c implantation: a 4-year prospective observational study.

PURPOSE: To investigate the changes in anterior lens density with a Pentacam after Implantable Collamer Lens (ICL) V4c implantation in patients with myopia. METHODS: This prospective case series examined 62 eyes of 32 patients (mean age, 28.5 ± 5.73 years) with myopia or myopic astigmatism after ICL V4c implantation. Uncorrected distance vision acuity, corrected distance vision acuity (CDVA), manifest refraction, intraocular pressure, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), endothelial cell density and Pentacam images of lens density were obtained pre- and postoperatively. The vault was obtained during the follow-ups. RESULTS: Patients were followed up for an average of 51 ± 2.7 months (range, 48-57 months). All surgeries were uneventful, without any complication. The efficacy and safety indices at the last follow-up were 1.03 ± 0.2 and 1.22 ± 0.22, respectively. No eye had decreased CDVA, and 66% eyes gained ≥1 line. Furthermore, refractive error in 90% eyes was within ±0.50 D and that of 100% was within ±1.0 D of the attempted refraction. Anterior average lens density (a-ALD) in the 0.5-, 1.0- and 1.5-mm depth zones increased by 10.41 ± 11.51%, 17.1 ± 11.09% and 16.76 ± 10.4%, respectively, compared to preoperative values (all p < 0.05). The change in a-ALD between two different age groups was not significant. Moreover, there were no significant correlations between the change in a-ALD and age, preoperative spherical equivalent, ACD, ACA, ACV or vault. CONCLUSIONS: Implantable Collamer Lens (ICL) V4c implantation demonstrates safety and efficacy for myopia correction. Although a-ALD increased slightly at 4 years postoperatively, no cataract developed during the follow-up. Further studies should investigate the reason for the postoperative increase in a-ALD.

One-year outcomes of 27G core-pars plana vitrectomy of idiopathic epiretinal membrane.

The present study aimed to assess the feasibility and safety of 27G core-pars plana vitrectomy (PPV) for idiopathic epiretinal membrane (IERM). A retrospective analysis was performed on 38 eyes from 38 patients with IERM with a mean age of 62.73±5.61 years. 27G core-PPV was combined with IERM and internal limiting membrane (ILM) peeling. Pre-operative and post-operative best-corrected visual acuity (BCVA) and lens density were measured. Optical coherence tomography (OCT) and OCT angiography were performed to determine the patients' macular area. Ultrasound biomicroscopy and B-mode ultrasound were subsequently performed to observe any complications and the follow-up period ranged from 1 week to 12 months post-operatively. A total of 36 patients achieved visual improvement of ≥2 Snellen lines, of which 33 patients exhibited improvements within 1 week and the lens density remained unchanged. The mean central macular thickness significantly decreased at 12 months post-operatively (P≤0.05); however, it was not observed to be correlated with BCVA (r=0.41; P>0.05). The foveal avascular zone of the affected eye was significantly smaller than that of the healthy fellow eye (P≤0.05) and negatively correlated with post-operative BCVA (r=-0.72; P≤0.05). Superficial retinal capillary density and deep retinal capillary density decreased post-operatively (both P≤0.05) and no complications were observed. Taken together, the results of the present study indicate that application of 27G core-PPV with ILM peeling is minimally invasive for IERM and facilitates rapid post-operative BCVA recovery.

Evaluation of the effect of fasting on intraocular pressure, anterior segment parameters and density of crystalline lens and cornea.

PURPOSE: To evaluate the effect of fasting on anterior chamber depth, anterior chamber volume and corneal and lens density by Scheimpflug technology and to measure intraocular pressure changes. METHODS: Totals of 50 healthy fasting individuals in Ramadan (study group) and 50 healthy non-fasting subjects (control group) were included. Central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), corneal density (CD) and lens density (LD) were evaluated with Scheimpflug technology. Intraocular pressure (IOP) was measured with applanation tonometry. Both eyes of each participant were examined and also compared. RESULTS: Comparison of groups: There was a statistically significant difference between CD, ACD, ACV and IOP (respectively, right/left eye: fasting: CD: 12.81 ± 0.76/12.73 ± 0.73; ACD: 2.92 ± 0.37 mm/2.93 ± 0.37 mm; ACV: 168.3 ± 41.82 mm3/183.34 ± 32.46 mm3; IOP: 13.80 ± 1.22 mmHg/14.88 ± 2.73 mmHg; non-fasting: CD: 13.28 ± 1.01/13.17 ± 0.77; ACD: 3.06 ± 0.31 mm/3.07 ± 0.31 mm; ACV: 167.46 ± 42.92 mm3/180.68 ± 31.45 mm3; IOP: 13.60 ± 1.65 mmHg/14.74 ± 2.93 mmHg) values on the right side (p < 0.01, p = 0.03, p = 0.04, p = 0.01, respectively). Although there was a statistically significant difference between the ACV, CD and IOP values on the left side (p < 0.01, p = 0.03, p = 0.01, respectively), no statistical significance was found for the ACV value on the left side (p = 0.08). CONCLUSION: The results demonstrated that, while fasting did not lead to any change in LD and CCT, it caused a small decrease in ACD and ACV, and a significant decrease in CD and IOP values. Scheimpflug technology seems to be a valuable tool for the evaluation of anterior segment changes in patients who are fasting.

Correlation between lens thickness and lens density in patients with mild to moderate cataracts.

PURPOSE: To determine the relationships between lens thickness (LT), lens density and anterior segment parameters in patients with mild to moderate cataracts. SETTING: Oftalmosalud Instituto de Ojos, Lima, Perú. DESIGN: Prospective, single-centre, cross-sectional study. METHODS: 169 eyes with age-related mild to moderate cataracts had lens density assessed using the Lens Opacification Classification System III, the built-in Pentacam HR Nucleus Staging software and ImageJ software. LT and axial length (AL) were measured with the IOLMaster 700, and angle parameters were measured using anterior segment optical coherence tomography. Pearson correlation coefficients and Kruskal-Wallis tests were used for statistical analyses. RESULTS: Nuclear colour score was the only clinical parameter with a weak significant correlation with LT (r=0.24, p=0.003) after accounting for age, AL, gender and anterior chamber depth (ACD). The maximum value of average lens density and the mean nuclear density were significantly correlated with LT (r=0.24, p=0.003 and -0.17, p=0.03, respectively) after controlling for the same factors. Central LT greater than 4.48 mm was present in 54.5% of the eyes with a nuclear opalescence grade 1. CONCLUSIONS: LT is independent of lens density in mild to moderate cataracts after accounting for age, AL, ACD and gender contrary to previous studies.

Impact of lens density and lens thickness on cumulative dissipated energy in femtosecond laser-assisted cataract surgery.

To evaluate the required cumulative dissipated energy (CDE) to fragment the crystalline lens in femtosecond laser-assisted cataract surgery (FLACS) in relation to lens density and lens thickness. Consecutive eyes that underwent FLACS between September 2014 and March 2017 by a single surgeon using in all cases the same femtosecond laser and phacoemulsification platform were included in our retrospective study. Prior to surgery, corrected distance visual acuity (CDVA), optical biometry corneal, and crystalline lens tomographies were performed to assess anterior chamber depth (ACD), axial length (AL), and crystalline lens parameters (i.e., lens density, thickness, and nucleus staging (NS)). After surgery, CDE was calculated and analyzed in relation to lens density (LD) and lens thickness (LT). Zero ultrasound expenditure cases were recorded and their occurrence analyzed. The chart review identified 236 eyes of 200 patients, 98 males and 102 females aged 65± 15 years which were included in the study. Mean LD was 11.26 ± 2.05 pixel intensity units (range 7.30-18.80), and the mean LT was 3417 ± 405.17 µm (range 2545-4701). LD and LT correlated moderately (r = 0.50, p < 0.001) and weakly (r = 0.23, p < 0.001), with post-laser CDE. Higher LD and LT were also associated with lower rates of zero phaco (eyes in which no phacoemulsification energy was necessary). Furthermore, NS (r = 0.528, p < 0.001) and CDVA (r = - 0.3524, p < 0.001) also correlated with CDE. Higher LD, LT, NS values, and low CDVA are associated with higher ultrasound expenditure (CDE-cumulative dissipated energy) and with lower rates of zero ultrasound expenditure during FLACS.

Intra-correlations between cataract density based on Scheimpflug image, phacodynamics, surgery duration, and endothelial cell loss after phacoemulsification.

PURPOSE: To assess intra-correlations between lens density based-on Scheimpflug Imaging System, power used during surgery, surgery duration, and endothelial cell loss in eyes with nuclear cataract. SETTING: Department of Ophthalmology, King Fahd Hospital of the University, Alkhobar, Saudi Arabia. DESIGN: Prospective cross-sectional observational study. METHODS AND MATERIAL: The objective lens density and endothelial cell density were measured using the Scheimpflug system and specular microscopy, respectively. Intra-operatively, all phacodynamic parameters and duration of the surgery were documented. RESULTS: This study of 62 patients (71 eyes) with a mean age of 58.56 ±â€¯10.4 years. The mean Scheimpflug-measured lens density was 13.93 ±â€¯3.27. The mean phacodynamic parameters, namely, power, ultrasound time, and elliptical motion were 13.63 ±â€¯6.38, 1.27 ±â€¯1.12, and 50.56 ±â€¯50.06, respectively. There were a positive linear correlations between the Scheimpflug-measured lens density and phacodynamic parameters, power (AVG %), ultrasound time, and elliptical motion (r = 0.501, r = 0.620, and r = 0.641, respectively; all P < .001), amount of endothelial loss (r = 0.445, P < .001), and surgery duration (r = 0.346; P < .01). Phacodynamic parameters were positively correlated with degree of endothelial loss (P < .01). The length of the surgery failed to show any correlation with damage happened to the endothelium (r = 0.210, P > .05). CONCLUSION: A positive correlations were observed between Scheimpflug-measured lens density with phacodynamic parameters, surgery duration, and endothelial loss. A strong correlation was observed between the degree of endothelial cell loss and phacodynamic parameters but not with the length of the procedure.

Comparability of subjective and objective measurements of nuclear density in cataract patients.

PURPOSE: To evaluate the relationship between subjective and objective measurements of lens density and the energy of phacoemulsification. SETTING: University Eye Clinic, Maastricht University Medical Centre, Maastricht, the Netherlands. DESIGN: Cross-sectional study. METHODS: The study population included 69 patients. Nuclear opalescence (NO) was graded with the Lens Opacities Classification System III (LOCS III). Thereafter, lens density was measured objectively with Scheimpflug imaging, anterior segment optical coherent tomography and spectral fundus reflectometry (SFR). Cumulative dissipative energy (CDE) and total ultrasound time (US t.t.) of the phacoemulsification were noted. The relationship between the different measurement techniques and energy of phacoemulsification was assessed using Spearman's correlation coefficients. RESULTS: We found moderate to strong correlations between LOCS III and objective measurements of the lens density (rho's from 0.53 to 0.78, p < 0.05) and a moderate correlation between three objective measurement techniques (rho's between 0.29 and 0.57, p < 0.05). There was a moderate correlation between CDE, US t.t. and lens density measurements (rho's from 0.29 to 0.55, p < 0.05), and the highest correlation was found between CDE and NO scores. Exclusion of patients with advanced cortical and posterior subcapsular opacities improved the correlation between SFR and lens density measurements but not the correlation with the energy of phacoemulsification. CONCLUSION: Lens Opacities Classification System III has shown the highest correlation with phacoemulsification energy and may be a preferred technique for prediction of use of phacoemulsification energy. Advanced cortical and posterior opacities may interfere with the quality of objective measurements but do not affect the correlation between lens density measurements and phacoemulsification energy.

Correlation of lens density and phacodynamics parameters in phacoemulsification / 眼科新进展

Objective To evaluate the correlation of lens density (LD) measured by opacity lensmeter (OLM) and Pentacam with phacodynamics in patients with age-related nuclear cataract.Methods A prospective study was conducted in 78 patients (78 eyes) with age-related nuclear cataract.The lens density was measured with OLM and Pentacam respectively before operation,and the phacoemulsification kinetic parameters in phacoemulsification,including ultrasound time (UST),cumulated dissipated energy (CDE) and balanced salt solution (BSS) usage,were recorded for the analysis of the correlations of LD values with phacodynamics.Results LD measured by OLM and Pentacam was 32.83 ± 14.41 and 15.26 ±5.82,respectively.LD from OLM and Pentacam was positively correlated with both UST (r =0.645,0.807,respectively;both P ＜ 0.05)and CDE (r =0.669,0.828,respectively;both P ＜ 0.05).UST and CDE were more strongly correlated with LD from Pentacam than from OLM (Z =2.153,2.283;both P ＜0.05).Conclusion LD from both OLM and Pentacam are correlated with UST and CDE,and a stronger correlation is observed in Pentacam than OLM.

Obesity and Density of the Crystalline Lens: Revisiting a Growing Dilemma.

BACKGROUND/AIMS: Obesity is believed to accelerate age-related cataractogenesis through various biomechanisms. On the contrary, there are also studies advocating the protective role of obesity against the cataract formation process. We investigate the correlation of body mass index (BMI) as a measure for obesity with crystalline optical lens density and opacity in a healthy adult population. METHODS: In a cross-sectional setting, 93 consecutive disease-free adult individuals who were working staff of a university-based hospital were assessed for the association between crystalline lens density and opalescence [measured by the objective Pentacam HR lens densitometry and subjective Lens Opacity Classification System III (LOCS III), respectively] with the degree of obesity as defined by BMI. RESULTS: LOCS III and crystalline lens density readings were positively correlated [Spearman rho CC (p value) = 0.224 (0.034)]. However, we found neither LOCS III nor crystalline lens density to be correlated with BMI [Spearman rho CC = -0.008 (p = 0.943) and -0.062 (p = 0.560), respectively]. CONCLUSIONS: Results from the present study indicate a lack of association between obesity and densitometry of the crystalline in the adult population group. Further studies are required to confirm the order of causality and pathogenesis of this finding.

Useful Prediction of Phacodynamics by Scheimpflug Lens Densitometry in Patients over Age 70.

PURPOSE: To evaluate the relationship between lens density using the Scheimpflug system and phacodynamics in nuclear cataracts as related to patient age. METHODS: In 262 eyes with nuclear cataracts, the objective lens density was determined by Pentacam Nucleus Staging (PNS) software while subjective grading was achieved using the Lens Opacities Classification System III (LOCS III). RESULTS: Overall, cumulated dissipated energy (CDE) had a positive correlation with Scheimpflug lens density and LOCS III nuclear scores. When analysis was done by patient age, LOCS III nuclear scores and Scheimpflug lens density had a positive correlation with CDE for patients in all age groups. Of interest, patients >70 years old showed a higher correlation coefficient (r) with Scheimpflug lens density than with LOCS III nuclear score. CONCLUSIONS: Scheimpflug lens densitometry may be more useful for predicting phacodynamics than LOCS III scores in nuclear cataract patients, especially in old age (>70 years).

Quantitative Scheimpflug camera study of the lens density in healthy Turkish population.

The purpose of this study is to evaluate the association between the age and the density of anterior, posterior, and nuclear parts of lens and detect the normal lens density (LD) values in different age groups. 370 eyes of 370 voluntary healthy Turkish subjects were included. These were divided in four groups according to their age. These were Group 1 (51-65 years), Group 2 (41-50 years), Group 3 (31-40 years) and Group 4 (20-30 years). LD values of anterior, nuclear, posterior, and total (average) were measured using Pentacam HR Scheimpflug camera system. Both eyes of each subject were scanned twice in automatic release and 50-picture 3-dimensional (3D) scan modes by one experienced observer. 207 of the participants were females and 163 were males, with a mean age of 40.57 ± 13.06 years. The differences between groups in terms of nuclear area, posterior area, and average LD measurements were significant but anterior area was not. The nuclear area and average LD had high positive correlation with age (r = 0.72, p < 0.001, r = 0.63, p < 0.001, respectively); posterior area LD had a weak negative correlation with age (r = -0.16, p = 0.001). The mean LD values between female and male subjects showed no significant difference. The anterior region of the lens has the highest and nuclear area has the lowest value of LD in young people. In older people, the anterior area did not show a significant change, nuclear and total areas showed a significant increase but posterior area showed a significant decrease.

Ocular parameters of biological ageing in HIV-infected individuals in South Africa: relationship with chronological age and systemic biomarkers of ageing.

HIV-infected individuals have an increased risk of age-related morbidity despite antiretroviral treatment (ART). Several anatomic and functional ophthalmological parameters are associated with increasing chronological age. These may, therefore, potentially serve as biomarkers of ageing. We investigated associations between ocular parameters (lens density, retinal vessel calibre, corneal endothelium and retinal nerve fibre layer thickness) and two 'cellular' biomarkers of ageing (leukocyte telomere length and CDKN2A expression) and with frailty in a cross-sectional study of 216 HIV-infected individuals. All ocular parameters, telomere length and frailty were associated with chronological age, whereas CDKN2A expression was not. Retinal venular calibre and lens density were associated with shorter telomere length (p-trend=0.04, and 0.08, respectively), whereas CDKN2A expression and frailty status were not associated with ocular parameters. Longitudinal studies are warranted to assess the integration of retinal vascular calibre and lens density with systemic markers to develop an overall index of biological ageing in HIV infection.

Myopic refractive shift represents dense nuclear sclerosis and thin lens in lenticular myopia.

BACKGROUND: It is not rare to meet unilateral nuclear sclerotic cataracts with myopic refractive changes (lenticular myopia) compared with the fellow eye in the ophthalmic examination of patients with decreased visual acuity. To determine the relationship between the myopic refractive changes and interocular differences of parameters, we investigated the interocular differences of ocular parameters between a lenticular myopic eye and the fellow eye. METHOD: This retrospective study included 68 eyes of 34 patients, who showed unilateral lenticular myopia. We compared the dimensions of ocular component, such as anterior chamber depth, anterior chamber volume, lens thickness, vitreous chamber depth, lens position, lens density of nuclear sclerosis, anterior lens curvature and myopic refractive changes (spherical equivalent refraction) between the lenticular myopic eye and the myopic refractive change were examined. RESULTS: Statistically significant differences were found between the lenticular myopic eye and the fellow eye for anterior chamber depth (p = 0.015) anterior chamber volume (p = 0.031), lens thickness (p < 0.001), lens density of the nuclear sclerosis (p < 0.001) and the spherical equivalent myopic refractive changes (p < 0.001). Based on univariate analysis, the interocular difference in spherical equivalent refraction was significantly correlated with interocular differences of the density of the nuclear sclerosis (r = 0.79, p < 0.001), lens thickness (r = -0.70, p < 0.001) and vitreous chamber depth (r = 0.43, p = 0.012). Based on multiple regression analysis, the interocular difference in spherical equivalent refraction was significantly correlated with interocular differences of density of nuclear sclerosis (p < 0.001) and lens thickness (p = 0.007). CONCLUSION: The difference in myopic spherical change reflects the differences in the severity of nuclear sclerosis and lens thickness between the lenticular myopic eye and the fellow eye.

Clinical applications of Scheimpflug imaging in cataract surgery.

Since the Scheimpflug principle was first described over a century ago, there has been a great interest among ophthalmologists for the use of Scheimpflug camera in anterior segment imaging. Scheimpflug imaging has since advanced significantly and modern day instruments provide comprehensive imaging and topographic data of the anterior segment. In this article the clinical applications and limitations of Scheimpflug imaging in modern cataract surgery patients are discussed. This article reviews recent work on assessment of lens transparency for cataract grading and integrity, using preoperative lens density measurements to help predict phacoemulsification parameters, its utility in challenging situations like capsular bag distension syndrome and traumatic cataract and assessment of density of the posterior capsule for objectively quantifying posterior-capsule opacification.