Progression Of Posterior Subcapsular Cataract Research Articles

Elevated level of uric acid in aqueous humour is associated with posterior subcapsular cataract in human lens

Age-related cataract is the leading cause of blindness worldwide. The pathological mechanisms causing this disease remain elusive. To examine the involvement of uric acid (UA) in the pathogenesis of posterior subcapsular cataract (PSC). Retrospective study and experimental investigation. A total of 180 patients with PSC or non-PSC were included. Samples obtained from the patients were used to analyse content of UA and for histochemical examinations. The effects of UA on human lens epithelial cells were also investigated. Aqueous humour UA and urate deposits. The results showed a significant increase of aqueous humour UA in patients with PSC. After adjustment for potential confounders, elevated aqueous humour UA (odds ratio [OR] = 1.45) showed a stronger association with PSC than serum UA (OR = 1.10). Gomori methenamine silver staining revealed in PSC an intense deposit of urates in the lens fibres in equatorial regions, and in subcapsular fibres in posterior regions of the lens. Such staining was not detected in the lens with non-PSC. Treatment with UA-induced senescence and apoptosis in human lens epithelial cells in a dose dependent manner. Our results suggest that the elevated level of UA in aqueous humour causes a deposition of urates in human lens epithelium, which could possibly lead to dysfunction of these cells that generates opacification in PSC. These findings indicate the local action of excessive UA in the pathogenesis of PSC. Control of serum UA level could delay the progression of PSC.

Spatio-temporal control on the delivery of triamcinolone acetonide using polymeric nanoparticles reduces steroid induced cataract.

Development of topically administered drug delivery systems for the treatment of ocular diseases have majorly focused on enhancing bioavailability of drugs in the ocular tissues. However, control of spatial distribution of topically administered drugs so as to restrict/avoid drug bioavailability at sensitive ocular tissues that are prone to drug induced adverse effects has not been explored. In this study, we aimed to reduce the bioavailability of topically administered corticosteroid, triamcinolone acetonide (TA) in lens via controlled spatial distribution in order to minimize TA induced posterior subcapsular cataract (PSC). For this, a negatively charged polymeric core-shell nanoparticulate drug delivery system composed of polycaprolactone (PCL) core and pluronic® F-68 (PF68) shell was fabricated. For in vivo studies, coumarin-6 (COU) loaded nanoparticles (NPs) were fabricated and studied for their biodistribution after topical administration in mice eyes and compared with free COU biodistribution. The administered COU loaded NPs differentially distributed in mice eyes and showed lower bioavailability in lens compared to free COU. Further, in vivo efficacy of the delivery system for its ability to minimize the rate of PSC progression was evaluated in diabetic rats. The results demonstrated that TA loaded PCL-PF68 NPs decreased PSC progression compared to free TA when administered topically.

Incidence, Progression, and Risk Factors for Cataract in Type 2 Diabetes.

We report the 4-year incidence, progression, and risk factors of cataract subtypes in type 2 diabetes. A total of 779 subjects completed baseline and 4-year follow-up. The incidences of nuclear opalescence (NO), nuclear color (NC), cortical cataract (CC), and posterior subcapsular cataract (PSC) were 70%, 55.2%, 25.7%, and 7.3%, respectively. One-step progressions of NO, NC, CC, and PSC were 14.3%, 16.1%, 8.8%, and 8.1%, respectively, and two-step or more progressions were 5.0%, 6.0%, 0.8%, and 6.0%, respectively. Incident NO was seen in patients 50 to 59 (odds ratio [OR] = 3.3), NC in those 50 to 59 (OR = 2.7) and 60 to 69 (OR = 3.9), and CC in those 60 to 69 (OR = 3.3) years old. A lower hemoglobin A1c (HbA1c; OR = 0.7), longer diabetes duration (OR = 1.1), and hyperopia (OR = 4.0) were associated with incident PSC. Women (OR = 1.7) and patients with higher total cholesterol (OR = 1.3) at baseline showed one-step NO progression. Patients 60 to 69 (OR = 2.8) and ≥70 (OR = 3.8) years old showed one-step NC progression, while those 60 to 69 years old showed one-step CC progression (OR = 6.3). A lower HbA1c (OR = 0.3) was associated with one-step PSC progression. A higher low-density lipoprotein (OR = 1.6) was associated with two-step or more NO progression. Patients 60 to 69 years old (OR = 6.7) had a greater risk, while those with hyperopia at baseline (OR = 0.2) had lower risk of two-step or more NC progression. Patients 40 to 49 years old constituted the reference group for all. The 4-year cumulative incidence of cataract is higher than that of progression. Greater age is a risk factor for incidence and progression of most types of cataract.

Triamcinolone‐induced cataract in eyes with diabetic macular oedema: 3‐year prospective data from a randomized clinical trial

To describe the 3-year risk of cataract after intravitreal triamcinolone (IVTA) injections for diabetic macular oedema and the outcomes of cataract surgery. Prospective data from a randomized clinical trial were analysed. At baseline, 27 phakic eyes with diabetic macular oedema were randomized to receive IVTA and 25 to receive sham injection. After 2 years, initial sham-treated eyes were eligible to receive IVTA as the study became open label for the third year. The cumulative incidence of cataract surgery was the primary outcome of the study. Other outcomes assessed included progression of cataract, best-corrected logarithm of the minimal angle of resolution visual acuity before and after surgery and central macular thickness. Over the 3 years of the study, 15/27 (56%) phakic eyes in the IVTA treated group underwent cataract surgery as compared with 2/25 (8%) initial sham-treated eyes (P < 0.001). Mean visual acuity 6 months after cataract surgery was better than at entry into the trial. Two (15%) of the eyes in the IVTA-treated group undergoing cataract surgery had a loss of >15 letters. In the IVTA-treated group, 10/15 (67%) eyes that had three or more injections had progression of posterior subcapsular cataract by > or = 2 grades as compared with only 2/12 (17%) eyes that had fewer than three injections (P = 0.009). Over half of the eyes receiving IVTA injections for diabetic macular oedema required cataract surgery within 3 years. In eyes with three or more IVTA injections, two-thirds had progression of posterior subcapsular cataract. Visual outcomes after cataract surgery were generally good, although a small proportion of eyes lost greater than 15 letters over the course of the study.

Adverse Events after Intravitreal Triamcinolone in Patients with and without Uveitis

To evaluate the rates of adverse ocular events after intravitreal triamcinolone acetonide (IVTA) injection in patients with and without uveitis. Retrospective observational case series. Two hundred twenty-two eyes of 173 patients were included in the study: 45 eyes of 31 patients with macular edema (ME) due to uveitis and 177 eyes of 142 patients with ME secondary to other etiologies. Retrospective review of patients who received IVTA at the Cole Eye Institute for ME attributable to various causes between the years 2001 and 2005. Data review of clinical records included patient demographics, etiology of ME, and adverse outcomes after injection. Rates of adverse outcomes in patients with and without uveitis were compared. Intraocular pressure (IOP) elevation and posterior subcapsular cataract (PSC) progression. Uveitis patients were significantly younger, more likely to be female, and more likely to have had prior posterior sub-Tenon's capsule steroid injection and/or glaucoma therapy than their nonuveitis counterparts. In a multivariate analysis adjusting for the differences in these factors, the presence of uveitis was the strongest risk factor for an adverse IOP event (odds ratio, 2.5; 95% confidence interval [CI], 1.0-6.1; P = 0.05). The odds of having a documented increase in PSC after IVTA injection were 5.6 times greater in uveitis eyes (P = 0.007; 95% CI, 1.6-19.6). Intraocular pressure elevation and PSC progression occurred with greater frequency in uveitis patients receiving IVTA. Patients with uveitis treated with IVTA should be counseled about these risks and monitored closely.

Intravitreal triamcinolone-induced elevated intraocular pressure is associated with the development of posterior subcapsular cataract

To investigate the association between elevated intraocular pressure (IOP) and accelerated cataract formation in patients treated with intravitreal triamcinolone. Analysis of longitudinal data from a randomized, double-masked, placebo-controlled trial of intravitreal triamcinolone for age-related macular degeneration (the Intravitreal Triamcinolone Study). Patients with phakic eyes who participated in a randomized clinical trial of intravitreal triamcinolone for age-related macular degeneration were studied. There were 57 phakic eyes in the treatment group and 54 phakic eyes in the control group. One eye per patient was studied. Four milligrams of intravitreal triamcinolone or 1 ml subconjunctival saline. Intraocular pressure rise of at least 5 mmHg (IOP responders) and progression of posterior subcapsular cataract by 2 or more grades using photographic standards from the Age Related Eye Disease Study. Progression of posterior subcapsular cataract (PSC) by 2 or more grades in the treatment group was significantly higher among 16 IOP responders (51% after 2 years) than among 37 nonresponders (3%; P<0.0001, log-rank test). There was no significant progression of PSC in the placebo group or the opposite eye of the treatment group. Progression of cortical cataracts also was significantly higher among responders than nonresponders (15% vs. 3%; P = 0.015, log-rank test). The progression of nuclear cataracts (13% vs. 3%) was not significantly different between IOP responders and nonresponders (P = 0.3, log-rank test). Although steroid-related cataracts are unlikely to develop in eyes that do not experience elevated IOP after intravitreal triamcinolone, those eyes that do also have a very high risk of rapidly experiencing posterior subcapsular lens opacification. This strong association suggests that the mechanism responsible for the development of steroid-induced PSC cataract and raised IOP may be similar.

Duration of vitrectomy and postoperative cataract in the vitrectomy for macular hole study

PURPOSE: To report the association between duration of vitrectomy, as well as other risk factors, and the progression of nuclear sclerosis and posterior subcapsular cataract in the Vitrectomy for Macular Hole Study. DESIGN: A cohort study nested within a randomized controlled clinical trial. METHODS: Using a system similar to the Lens Opacities Classification System II, nuclear sclerosis (NS) and posterior subcapsular cataract (PSC) were scored in the vitrectomy and fellow eye of 74 patients at baseline and at 6, 12, and 24 months postoperatively. Age, baseline blood pressure and refractive power, and duration of surgery were evaluated as risk factors for NS or PSC progression and cataract extraction. RESULTS: The incidence of NS progression in the surgical group of vitrectomy eyes was 81% at 6 months, 98% at 1 year, and 100% at 2 years of follow-up. In contrast, NS progression in the control group of fellow eyes was only 18% at 6 months, 20% at 1 year, and 8% at 2 years. The incidence of PSC progression in the surgical group remained at approximately 11% throughout follow-up, which was not significantly higher than the 3% to 5% incidence in the control group. Vitrectomy was significantly related to progression of NS cataract ( P < .001) and cataract extraction ( P < .01). No statistically significant differences were found for NS scores, PSC scores, or progression rates between eyes that had less than median surgical duration (60 min.) or more than the median surgical duration. Additionally, no significant differences were found when eyes that experienced 45 minutes or less surgical duration were compared with eyes that endured more than 75 minutes surgical duration. Age, blood pressure, and refractive power were not found to be predictors for NS and PSC progression. CONCLUSIONS: Although vitrectomy is a risk factor for NS progression, the duration of vitrectomy does not increase the risk.

Cataracts after autologous bone marrow transplantation in children

We recorded the incidence and degree of posterior subcapsular cataract (PSC) in 29 children who had undergone autologous (n = 28) or syngeneic (n = 1) bone marrow transplantation (BMT) due to haematologic or lymphoid malignancy. Conditioning prior to transplantation consisted either of a combination of chemotherapy and total body irradiation (TBI) (n = 21) or of chemotherapy only (n = 8). TBI was given in one fraction of 7.5 Gy. Nine patients had received previous cranial irradiation. The patients were followed for 4-10y (median 8 y) after transplantation. Of 29 patients, 22 developed PSC, all within 4 y after BMT. With the exception of one patient who developed unilateral PSC, all had received TBI. Conversely, 100% of those who received TBI developed PSC. In this group (+TBI), eight patients (38%) developed significant PSC, defined as best corrected visual acuity <0.8 in either eye. Six patients (10 eyes) have since needed surgical repair consisting of extracapsular cataract extraction and intraocular lens implantation. There was no clear relationship between previous cranial irradiation and cataract development, nor any other obvious baseline differences between those in the +TBI group who developed significant PSC and those who did not. Although effects of previous therapy cannot be ruled out, TBI appears to be the main cause of PSC in this group of patients. Twelve patients in the +TBI group had well-preserved visual acuity throughout the study, reflecting a slow progression of PSC. This compares favourably with previous reports of allogeneic BMT, possibly owing to less need for corticosteroids after autologous BMT. We conclude that the incidence of PSC was high after autologous BMT where the conditioning regimen included total body irradiation.

Cataracts after autologous bone marrow transplantation in children

We recorded the incidence and degree of posterior subcapsular cataract (PSC) in 29 children who had undergone autologous (n = 28) or syngeneic (n = 1) bone marrow transplantation (BMT) due to haematologic or lymphoid malignancy. Conditioning prior to transplantation consisted either of a combination of chemotherapy and total body irradiation (TBI) (n = 21) or of chemotherapy only (n = 8). TBI was given in one fraction of 7.5 Gy. Nine patients had received previous cranial irradiation. The patients were followed for 4-10 y (median 8y) after transplantation. Of 29 patients, 22 developed PSC, all within 4 y after BMT. With the exception of one patient who developed unilateral PSC, all had received TBI. Conversely, 100% of those who received TBI developed PSC. In this group (+TBI), eight patients (38%) developed significant PSC, defined as best corrected visual acuity < 0.8 in either eye. Six patients (10 eyes) have since needed surgical repair consisting of extracapsular cataract extraction and intraocular lens implantation. There was no clear relationship between previous cranial irradiation and cataract development, nor any other obvious baseline differences between those in the +TBI group who developed significant PSC and those who did not. Although effects of previous therapy cannot be ruled out, TBI appears to be the main cause of PSC in this group of patients. Twelve patients in the +TBI group had well-preserved visual acuity throughout the study, reflecting a slow progression of PSC. This compares favourably with previous reports of allogeneic BMT, possibly owing to less need for corticosteroids after autologous BMT. We conclude that the incidence of PSC was high after autologous BMT where the conditioning regimen included total body irradiation.