Effect of cataract incision type on corneal spherical aberration.

Corneal spherical aberration (CSA) plays an important role in the ocular refractive system. However, ophthalmologists have not considered the effect of difference cataract incisions on it. The purpose of this study is to investigate the effect of transparent corneal incision (TCI) and scleral tunnel incision (STI) on CSA after the cataract phacoemulsification with foldable IOLs. One hundred ninety-three eyes (61 males and 79 females) for 1-month observation and 114 eyes (29 males and 51 females) for 3-month observation with age-related cataracts (ARC) were included in this study. CSA was measured with dilated pupil by Pentacam Scheimpflug system at 1 day preoperative and 1, 3-month postoperative. Preoperative CSA >1.00 µm was excluded. Both TCI and STI are 3 mm incisions with Infiniti system and Ozil handpiece. No significant difference of age or gender was found between TCI and STI groups in 1 or 3-month observation. In 1-month observation, preoperative CSA for TCI and STI are 0.31 ± 0.29 and 0.41 ± 0.19 µm, which of postoperative are 0.42 ± 0.17 and 0.44 ± 0.35 µm, respectively. The change of CSA is 0.11 ± 0.32 and 0.04 ± 0.33 µm (P = .233). For 3-month observation, preoperative CSA for TCI and STI are 0.32 ± 0.28 and 0.36 ± 0.23 µm, which of postoperative are 0.43 ± 0.16 and 0.39 ± 0.26 µm, respectively. The change of CSA is 0.10 ± 0.34 and 0.03 ± 0.21 µm (P = .312). For the phacoemulsification combined with foldable IOL implantation, STI has minimal effect on CSA, but TCI might increase postoperative CSA.

[Long-term outcome after bilateral cataract surgery in infants with congenital cataract].

OBJECTIVE: To evaluate the long-term visual outcome and complications after bilateral congenital cataract surgery performed prior to 12 months of age. METHODS: A prospective case study. 31 cases (62 eyes) of bilateral congenital cataract were included.All patients received bilateral cataract extraction combined with primary capsulotomy and anterior vitrectomy simultaneously.After the operation, all patients wore aphakic glasses during the follow-up period.The unilateral and bilateral visual acuities (VA) at the last visit were determined and post-operative complications were evaluated, and the relationship between bilateral VA and the length of the follow-up period was also analyzed. RESULTS: The median age at surgery was 3.0 M (0.5 to 11 M) , the median follow-up period was 4.0 years (3.0 to 8.5 years). 37 out of 62 eyes (59.68%) achieved unilateral best corrected visual acuity equal or better than 0.3. 27 among 31 cases (87.1%) achieved binocular best corrected visual acuity equal or better than 0.3.Binocular best corrected visual acuity improved with the increase in the follow-up period and the patients' age (R(2) = 0.135,P = 0.0024) .Post-operative complications included strabismus (7 cases, 22.58%), nystagmus (13 cases, 41.94%), optical opacity (3 cases, 9.68%), ocular hypertension (1 cases, 3.23%). CONCLUSIONS: Surgery for congenital cataracts performed prior to 12 months of age is safe, and most of the subjects can achieve functional vision acuity. As these children age, the bilateral best corrected visual acuity can still keep improving.

Correlation between contrast sensitivity and the lens opacities classification system III in age-related nuclear and cortical cataracts.

BACKGROUND: Contrast sensitivity (CS) testing can detect differences in functional vision and is highly correlated with visual performance. This study was designed to investigate the association between CS and the grading score using the lens opacities classification system (LOCS) III as well as the association between CS and visual acuity (VA) in nuclear or cortical age-related cataract (ARC) patients. METHODS: A total of 270 eyes with ARC and 30 control eyes were divided into nuclear opacity (NO), nuclear color (NC), cortical cataract (C) based on LOCS III. The CS values measured at all spatial frequencies under photopic and glare conditions that resulted in contrast sensitivity function (CSF) were evaluated, and LogMAR VA was tested with the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. The correlation between CSF and LOCS III grading scores, and between CSF and LogMAR VA were analyzed. RESULTS: Compared to the controls, CSF of the nuclear or cortical ARC significantly declined. There are significant correlation between CSF and LogMAR VA, and between CSF and LOCS III grading scores. Compared to the VA, a stronger correlation existed between CSF and LOCS III grading score than that of LogMAR VA and LOCS III grading score. CS at some spatial frequencies is significantly influenced with LOCS III grading score. CONCLUSIONS: CSF significantly declined with the increasing ARC grading scores. Comparing to VA, CSF reflected the severity of cataract more comprehensively. CS at low spatial frequency is significantly influenced by ARC. Therefore, CS is more precise than VA in assessing the visual function of ARC patients.

Morphologic changes in the anterior chamber in patients with cortical or nuclear age-related cataract.

PURPOSE: To assess and compare the morphologic changes in the anterior segment in eyes with nuclear or cortical age-related cataract using Scheimpflug imaging. SETTING: Peking University People's Hospital, Beijing, China. DESIGN: Case-control study. METHODS: Patients with nuclear or cortical age-related cataract were recruited. The grade of nuclear opalescence or cortical opacity was assessed using the Lens Opacities Classification System III (LOCS III). A group of elderly subjects with a clear lens and normal vision served as the control group. Anterior chamber depth (ACD), anterior chamber volume (ACV), and lens thickness were evaluated using Scheimpflug imaging (Pentacam). RESULTS: Two hundred sixty-nine patients (330 eyes) were recruited. Thirty eyes were enrolled for each nuclear opalescence and cortical grade. The control group comprised 30 eyes (19 subjects). In eyes with age-related cataract, lens thickness increased with an increase in cortical opacity, whereas the ACD and ACV values decreased. The ACD was inversely correlated with LOCS III grades for nuclear opalescence (r = -0.197, P = .004), nuclear color (r = -0.195, P = .005), and cortical opacity (r = -0.508, P<.005). There were significant differences in lens thickness, ACD, and ACV between nuclear color, nuclear opalescence, and cortical opacity for LOCS III grades 3, 4, and 5, respectively. CONCLUSIONS: There were significant differences in lens thickness, ACD, and ACV between nuclear and cortical age-related cataracts. The ACD decreased more in eyes with cortical cataract, suggesting that the risk for angle-closure glaucoma may be greater in cases of cortical opacity in which lens expansion is greater. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

[Evaluation the value of Pentacam arterial segment analysis system in the study of anterior segment of the eye before and after laser periphery iridectomy].

OBJECTIVE: To evaluate the anterior segment parameters in early primary angle-closure glaucoma (PACG) and primary angle closure (PAC) eyes before and after neodymium:yttrium aluminum garnet (Nd:YAG) laser periphery iridectomy (LPI) by using Pentacam system. METHODS: Self-control study. Sixty one eyes of 33 patients were recruited into this study. The images of the anterior segment of the eye were captured and the parameters [i.e. the anterior chamber (AC) volume, the central AC depth, the peripheral AC depth, the peripheral AC angle and the pupil size] were measured by the Pentacam system pre-operatively and 1 week after laser treatment. RESULTS: The Pentacam system clearly showed the structure changes of the anterior segment after LPI (i.e. the convex configuration of the iris was flattened and the peripheral AC depth was deepened). The average AC volume (t=15.928), the peripheral AC depth (t=-17.399, -10.629, -12.576, -14.474) and the peripheral AC angle (t=-5.087) were increased significantly (P<0.01) after LPI. The AC volume was (74.10±16.35) mm3 before LPI and (94.10±18.42) mm3 after LPI, and the increases of peripheral AC depth were 0.17 mm (nasal) and 0.29 mm (temporal). There was no statistical significant changes in the AC depth before and after LPI. CONCLUSION: In patients with PACG and PAC, the changes of AC after LPI can be demonstrated by the Pentacam qualitatively and quantitatively.

Association of c3 gene polymorphisms with neovascular age-related macular degeneration in a chinese population.

PURPOSE: The purpose of this study was to determine whether the genetic polymorphisms of complement factor 3 (C3) are associated with neovascular age-related macular degeneration (AMD) in the Chinese population. METHODS: A total of 123 unrelated Chinese Han patients with neovascular AMD and 130 control subjects were recruited. Their six single-nucleotide polymorphisms (SNPs) in the C3 gene, one in the complement factor H (CFH) gene and two in the complement factor B (CFB) gene were characterized. Their genotypes, allele frequencies, and odds ratios were analyzed. RESULTS: The G allele of the C3 IVS2 rs2250656, but not other tested C3 SNPs of rs2230205, rs10411506, rs2230199, rs339392, and rs163913, was significantly associated with a reduced risk for AMD in the Chinese population (OR 0.605, 95% CI 0.39-0.93, p = 0.023), even after adjusting for age, gender, smoking status, CFH rs1061170, CFB rs4151667, and CFB rs641153 allele status (OR 0.58, 95% CI 0.35-0.96, p = 0.033). However, the C3 haplotype of A-A-C-A-T-T was identified as a statistically significant risk factor for neovascular AMD (OR 1.41, 95% CI 1.02-1.94). Furthermore, the C allele of the CFH rs1061170, but not the CFB rs4151667 and rs641153, was significnatly associated with increased risk for AMD (OR 3.09, 95% CI 1.55-6.15, p < 0.001). CONCLUSION: The G allele of C3 IVS2 rs2250656 may be a significantly protective factor for neovascular AMD in the Chinese population. This, together with low MAF of C3 R102G, may be partially responsible for the low prevalence of AMD in the Chinese population.

Morning glory syndrome associated with posterior lenticonus.

The clinical features of the morning glory syndrome (MSG) are demonstrated in a 12-year-old male patient with the posterior lenticonus in the left eye. This patient had retinal detachment in the left eye. A complete ocular examination was performed and the patient underwent a pars plana vitrectomy of the left eye. Slit-lamp examination revealed the posterior lenticonus with the posterior subcapsular opacities in the left eye. The fundus showed the symptoms of MGS. The discs were pink and deeply excavated, surrounded by a ring of chorioretinal pigmentary disturbance. The retina has remained reattached for six months after surgery. Although most cases of MGS present with retinal and vitrea abnormalities, it may also occur in association with the lens anomalies, including the posterior lenticonus and subcapsular cataract. This association may be helpful to explore the pathogenesis of MGS.

Axial length measurements before and after removal of silicone oil: a new method to correct the axial length of silicone-filled eyes for optical biometry.

A total of 67 eyes of 67 patients that have undergone vitrectomy and silicone oil tamponade for rhegmatogenous retinal detachment were included in this prospective clinical study. We measured the axial length (AL) and the anterior chamber depth (ACD) with A-mode ultrasonography and IOL Master before and after removal of silicone oil. Phase refractive indices of silicone oil at different wavelengths from 400 nm to 1000 nm were measured with an Abbe refractometer and a series of equations were derived to adjust the AL values obtained with the IOL Master in silicone-filled eyes. The instruments showed good agreement between the AL values measured before and after removal of silicone oil. The ACD values obtained with A-mode ultrasonography were lower than the values obtained with the IOL Master (p < 0.01). The AL values obtained with the IOL Master after removal of silicone oil were lower than the values obtained preoperatively (p < 0.01). The AL values obtained with the IOL Master after adjustment are more accurate than A-mode ultrasonography in silicone-filled eyes.

[Screening of cataract surgery in four rural populations aged 50 years old and above in western China].

OBJECTIVE: To estimate the cataract surgical coverage and cataract surgery rate and to assess the visual outcome of cataract surgery among individuals aged at or over 50 years old in four rural populations from four different areas of western China. METHODS: This cross-sectional study, performed during the period 2003 - 2005, used the method of cluster sampling and recruited 5562 persons aged 50 years old or above through household census. Standardized ocular examinations including visual acuity test, intraocular pressure measurement, slit-lamp and fundus examination were performed. The main outcome criteria were cataract surgical coverage, cataract surgery rate, complication rate and visual outcome after cataract surgery. RESULTS: Of individuals with bilateral presenting visual acuity < 6/60 due to age-related cataract, the cataract surgical coverage was 54% in Qinghai. It was the highest among these four populations. The highest cataract surgery rate (CSR) value was 1551 in Qinghai and the lowest 143 in Guangxi during the period of 2000-2002. The overall intraocular lens implantation rate was 51.5% in 200 eyes with cataract surgery and 40.5% eyes with post-operative visual acuity < 6/60. The overall post-operative complication rate was 28%. CONCLUSION: In the beginning of 21st century, the cataract surgical coverage in four rural populations aged 50 years old or above in western China was low and similar to the situation of the last decade in eastern China. Cataract surgical technique and low IOL implantation rate are the main causes for a poor visual outcome. To reduce the risks of cataract blindness, the clinicians should substantially improve the visual outcome as well as the number of cataract surgery.

[Prevalence of age-related cataract among adults aged 50 and above in four rural areas in western China].

OBJECTIVE: To assess and compare the prevalence of age-related cataract (ARC) among adults aged 50 years or older in Western China. METHODS: Questionnaire survey and ophthalmologic examination were conducted among 5562 permanent rural residents aged 50 years and above in Ping' an County, Qinghai Province, Chuxiong City, Yunnan Province, Liupanshui City, Guizhou Province, and Chongzuo City, Guangxi Zhuang Autonomous region, selected by cluster sampling. All lenses were graded and classified for lens opacities by slit lamp, using the Lens Opacification Classification System (LOCS) II and standard photographs. Definite ARC was defined as either LOGS II nuclear opalescence of grade 1.0 or more and/or cortical cataract of grade 1.0 or more and/or posterior subcapsular cataract of grade 1.0 or more in persons with the visual acuity worse than 10/16. RESULTS: The overall response rate was 88.4%. The prevalence rates of ARC in one or both eyes was 41.8% in Qinghai, 48.2% in Yunnan, 18.8% in Guizhou and 39.4% in Guangxi. After age correction under the data of China Census 2000, the age-adjusted prevalence of ARC correspondingly changed to 44.1% in Qinghai, 45.9% in Yunnan, 18.8% in Guizhou, and 32.8% in Guangxi. The prevalence of ARC increased significantly with increasing age. In those eyes with ARC, cortical cataract was more common in Qinghai and Guizhou, while nuclear cataract was more common in Yunnan and Guangxi. The proportion of grades 4 lens opacities in Qinghai was 17.49%, higher than those in Yunnan, Guizhou, and Guangri (15.58%, 11.03%, and 10.00%. respectively). CONCLUSIONS: Generally the ARC prevalence among the permanent rural residents aged 50 and above in Western China is higher than that in Eastern China. And there is difference in the prevalence rate among different areas. Special attention should be paid toward this situation.

Late postoperative capsular block syndrome versus liquefied after-cataract.

We report the case of a 76-year-old Chinese man who had uneventful cataract phacoemulsification and hydrophilic acrylic intraocular lens (IOL) implantation 6 years previously. He presented with decreased vision; a homogeneous milky substance was found between the posterior chamber IOL and the posterior capsule without IOL displacement or a change in the refractive status. The milky substance was aspirated from the capsular bag. Biochemical analysis showed the concentrations of proteins and Ca(++) in the milky liquid were higher than those in the aqueous humor. Protein identification by mass spectrometry indicated that the milky liquid contained a high concentration of alpha-crystallin and beta-crystallin.

Responses of human lens epithelial cells to quercetin and DMSO.

PURPOSE: Oxidative stress is an initiating factor in the development of maturity-onset cataract. Diet has a significant impact on cataract development, and individual dietary components responsible for the protective effect include flavonoids, of which quercetin is the most important. The purpose of this study was to investigate the protective effect of quercetin and its toxicity for human lens epithelial cells (HLECs). METHODS: HLECs in culture were incubated for 48 hours with either 1% (vol/vol) dimethyl sulfoxide (DMSO) alone or with this concentration of DMSO and between 0.1 and 100 microM of quercetin. Nonstimulated cells served as control cultures. The viability of HLECs was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay. Gene expression was assessed with reverse transcription-polymerase chain reaction (RT-PCR). Cellular apoptosis was examined by in situ immunocytochemistry using terminal deoxynucleotidyl transferase-mediated biotin-dUTP nicked labeling (TUNEL) and by flow cytometry, using annexin V-FITC apoptosis detection. RESULTS: DMSO (1% vol/vol) decreased cell viability, increased cellular apoptosis, and upregulated Bax in these cells; 0.1 microM quercetin inhibited these effects and protected HLECs from the toxicity of DMSO. Higher concentrations of quercetin the viability of HLECs decreased. In a dose-dependent response to quercetin, cellular apoptosis increased and the change correlated with upregulation of Bax and decreased cell viability. CONCLUSIONS: Quercetin, at a low concentration (0.1 microM), protects HLECs and reverses the toxic effects of DMSO (1% vol/vol). However, at higher concentrations, quercetin is toxic to HLECs with an LD(50) of 90.85 microM. Quercetin induced apoptosis and upregulates apoptotic genes in HLECs in a dose-dependent manner.

[Measurement of central corneal thickness in myopic eyes with ultrasound and Pentacam scheimpflug system].

OBJECTIVE: To assess the accuracy and variability of central corneal thickness measurements in myopic eyes obtained by ultrasound pachymetry and the Pentacam scheimpflug imaging system. METHODS: First, corneal thickness in 50 healthy eyes was measured three times with the Pentacam system to evaluate the repeatability. Then, Scheimpflug imaging system (Pentacam) and A-scan ultrasonic pachymeter (SP-3000) were used to measure the corneal thickness on 217 myopic cases (433 eyes) undergoing laser in situ keratomileusis (LASIK) and 63 cases (126 eyes) 6 months after LASIK. The results were compared. RESULTS: Repeated-measures ANOVA showed the repeatability of the Pentacam measurements was high (P > 0.05). Pre-operatively, the value of corneal central thickness measured by ultrasonic pachymetry and the Pentacam system was (537.26 +/- 31.61) microm and (538.08 +/- 32.72) microm, respectively. There was no significant difference between the results of these two methods (t = 1.867, P > 0.05). The difference between these two methods ranged -35 - 34 microm, and was within -20 - 20 microm in 95.38% cases. Post-operatively, the value of corneal central thickness measured by ultrasonic pachymetry and the Pentacam system was (464.21 +/- 41.04) microm and (465.17 +/- 42.65) microm, respectively. There was no significant difference between these two methods, too (t = 0.913, P > 0.05). There was a significant linear correlation between the two methods (P < 0.001). The thinnest point of cornea was mostly located surrounding the apex and inclined towards inferotemporal. CONCLUSION: The Pentacam scheimpflug system offers an acceptable method for evaluating corneal pachymetry, which is useful in corneal refractive surgery.

[Preoperative clinical features and surgical results of congenital cataract].

OBJECTIVE: To evaluate the relationship between preoperative nystagmus and visual outcome of congenital cataract surgery. METHODS: Retrospective review of 81 patients (84 eyes) who underwent surgery for cataract was conducted,in which 7 cases of unilateral cataract and 3 of bilateral cataract were associated with preoperative nystagmus. All patients lacked other structural ocular defects or neurologic abnormalities and were old enough to cooperate with recognition visual acuity testing. Outcome parameters studied were best-corrected postoperative visual acuity of the eyes. RESULTS: Best corrected postoperative visual acuity of the nystagmus eyes was 0.05 or worse in 3 (23%, 3/13), between 0.05 and 0.3 in 9 (69%, 9/13), and 0.3 or better in 1 (8%, 1/13). Best corrected visual acuity of the eyes without nystagmus was 0.05 or worse in 6 (8%), between 0.05 and 0.3 in 24 (34%), and 0.3 or better in 41 (58%) h. There was a statistical significance of preoperative visual acuity compared to postoperative visual acuity in cataract with (P= 0.04) or without nystagmus. The great statistical significance was shown in the improvement of visual acuity between the patients with nystagmus and without nystagmus. CONCLUSION: Preoperative nystagmus in children with cataract does not preclude visual improvement, but may predict a poorer visual acuity outcome after cataract surgery. In these patients a decision must be made as to whether or not surgical intervention for the cataract would be worthwhile at this stage.