Topical bromfenac reduces multiple inflammatory cytokines in the aqueous humour of pseudophakic patients.

Intraocular surgery is associated with increased ocular inflammation. If maintained for a prolonged period after surgery, this inflammation can cause various complications, including subconjunctival fibrosis and bleb scarring. This clinical trial was a prospective, randomised, single-blind, interventional study comparing the efficacy and safety of 0.1% bromfenac sodium ophthalmic solution and 0.02% fluorometholone ophthalmic suspension in the inhibition of multiple inflammatory cytokines in the aqueous humour of 26 patients with pseudophakic eyes who had undergone phacoemulsification and intraocular lens implantation. The patients were randomly assigned to one of the trial drugs, and aqueous humour samples were collected before and after drug administration. Platelet-derived growth factor-AA levels significantly decreased in both drug groups, but they were significantly higher in the fluorometholone group than in the bromfenac group (P = 0.034). Bromfenac also significantly decreased vascular endothelial growth factor level (P = 0.0077), as well as monocyte chemoattractant protein-1 level (P = 0.013), which was elevated for a prolonged period after phacoemulsification. These data suggest that bromfenac is useful to alleviate prolonged microenvironmental alterations in the aqueous humour of pseudophakic eyes.

Cytokine profiles of phakic and pseudophakic eyes with primary retinal detachment.

PURPOSE: To compare the cytokine profiles of phakic (p) and pseudophakic (ps) eyes with primary rhegmatogenous retinal detachment (RD) to eyes with macular holes (MH) and to identify differences in the specific cytokine profiles. METHODS: Aqueous humour (AH) and vitreous fluid (VF) were obtained from patients with primary RD without proliferative vitreoretinopathy undergoing vitrectomy. AH and VF of patients with macular holes (MH) served as controls. Forty-three different cytokines were quantified using multiplex cytokine analysis. Intergroup and intragroup comparisons were performed. To control for multiple comparisons, Holm's correction was applied. RESULTS: VF and AH samples of 71 eyes with RD (pRD N = 38; psRD N = 33) and 26 eyes with MH were included. Cytokine levels in psRD and pRD were similar (none with >10-fold difference). The levels of 39 of 43 cytokines in the VF were significantly higher in eyes with RD than in those with MH (>10-fold: CXLC5, CCL26, CCL1, IL-6, CXCL11, CCL7, CCL13, MIG/CXCL9, CCL19 and TGF-ß1). In the AH, 23 of 43 cytokines were significantly higher compared to MH (>10-fold: CXCL5, IL-4, IL-6, IL-8/CXCL8 and CCL7). CONCLUSION: A complex, but nonspecific cytokine environmental response seems to initiate immunological and profibrotic processes following RD. Relevant differences in the cytokine profiles of eyes with pRD and psRD were not identified, whereas cytokine differences between AH and VF in RD could be explained by upregulation in the vitreous, a higher turn around in the anterior chamber, or differences in inflammatory cascades in both compartments.

Effects of Vitrectomy and Lensectomy on Older Rhesus Macaques: Oxygen Distribution, Antioxidant Status, and Aqueous Humor Dynamics.

Purpose: The purpose of this study is to evaluate effects of vitrectomy (PPV) and lens extraction with intraocular lens implantation (PE/IOL) on molecular oxygen (pO2) distribution, aqueous humor antioxidant-oxidant balance, aqueous humor dynamics, and histopathologic changes in the trabecular meshwork (TM) in the older macaque monkey. Methods: Six rhesus monkeys underwent PPV followed by PE/IOL. pO2, outflow facility, and intraocular pressure (IOP) were measured. Aqueous and vitreous humor specimens were analyzed for antioxidant status and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative damage. TM specimens were obtained for immunohistochemical and quantitative PCR analysis. Results: pO2 at baseline revealed steep gradients in the anterior chamber and low levels in the posterior chamber (PC) and around the lens. Following PPV and PE/IOL, pO2 significantly increased in the PC, around the IOL, and angle. IOP increased following both surgical interventions, with no change in outflow facility. Histopathologic analysis did not show changes in TM cell quantification, but there was an increase in 8-OHdG. Quantitative PCR did not reveal significant differences in glaucoma-related gene expression. Aqueous and vitreous humor analysis revealed decreased ascorbate and total reactive antioxidant potential and increased 8-OHdG in the aqueous humor only in the surgical eyes. Conclusions: Oxygen distribution in the older rhesus monkey is similar to humans at baseline and following surgical interventions. Our findings of histopathologic changes of TM oxidative damage and alterations in the oxidant-antioxidant balance suggest a potential correlation of increased oxygen exposure with oxidative stress/damage and the development of open angle glaucoma.

FACTORS ASSOCIATED WITH PENTOSIDINE ACCUMULATION IN THE HUMAN VITREOUS.

PURPOSE: To explore factors associated with pentosidine accumulation in the human vitreous. METHODS: Vitreous samples were obtained during trans pars plana vitrectomy for macular hole or rhegmatogenous retinal detachment. Patient characteristics included age, gender, and diabetes mellitus. Ocular characteristics included pseudophakia, posterior vitreous detachment, and presence of intraocular fibrosis (epiretinal membrane, proliferative vitreoretinopathy, or both). Pentosidine concentration as a measure of accumulation of advanced glycation end products was determined by high performance liquid chromatography. RESULTS: Pentosidine concentrations were measured in 222 vitrectomy samples (118 female and 104 male patients [median age 66 years], treated for macular hole [n = 105] or rhegmatogenous retinal detachment [n = 117]). Pentosidine was found to accumulate significantly with age (P < 0.001). After correction for age, a multivariable linear regression model revealed significantly higher pentosidine values in eyes with intraocular fibrosis (P = 0.001), in phakic as compared with pseudophakic eyes (P = 0.02), and in the absence of a complete posterior vitreous detachment (P = 0.018). The authors found no association with diabetes mellitus or gender. CONCLUSION: This study confirmed an age-related pentosidine accumulation in the vitreous and found new factors relating to pentosidine levels. Findings support the hypothesis of enzyme-induced vitreous liquefaction and the hypothesis of pentosidine as a pro-fibrotic factor.

Increased levels of inflammatory immune mediators in vitreous from pseudophakic eyes.

PURPOSE: To determine if pseudophakic eyes have an increased and sustained level of inflammatory immune mediators in the vitreous compared to phakic eyes. METHODS: Vitreous fluid samples were obtained from 73 patients undergoing elective pars plana vitrectomy (PPV) as a result of a macular hole, epiretinal membrane, vitreous macular traction, or vitreous floaters. Forty eyes were pseudophakic and had previously undergone uncomplicated cataract surgery, ranging from a few months to several years prior to PPV. The vitreous samples were analyzed for 29 different inflammatory immune mediators using multiplex bead immunoassays. RESULTS: A total of 14 cytokines (eotaxin, interferon-γ-induced protein-10 [IP-10], monocyte chemotactic protein-1 [MCP-1], macrophage derived chemokine [MDC], macrophage inflammatory protein [MIP]-1α, MIP-1ß, thymus activation regulated chemokine [TARC], IL-12p40, IL-15, IL-16, IL-7, VEGF, IL-6, and IL-8) were detected in the vitreous of both study groups. Using multiple linear regression analysis, pseudophakia was significantly correlated with higher levels of vitreous immune mediators compared to phakia. Elevated vitreous levels were estimated to decrease over time for IL-6, IL-8, IL-15, IL-16, and VEGF, though they remained elevated for many months and even years compared to the levels detected in phakic eyes. CONCLUSIONS: This is the first study to demonstrate that cataract surgery and pseudophakia can induce increased vitreous levels of a substantial range of inflammatory immune mediators. The elevated levels seem to be maintained for a long period of time. These increased levels of cytokines may be involved in inflammatory processes leading to several complications to cataract surgery, both early and late.

Recurrence of aqueous misdirection following pars plana vitrectomy in pseudophakic eyes.

We present a retrospective interventional case series of four patients with pseudophakic eye who developed recurrent aqueous misdirection following pars plana vitrectomy (PPV) for malignant glaucoma (MG). The patients were treated with neodymium: YAG (Yttrium Aluminum Garnet) laser hyaloidotomy/membranotomy through the patent peripheral iridectomy. The main outcome measure was resolution of MG. The intervention resulted in resolution of MG in all four cases. The cause for recurrence was an inflammatory membrane covering the hyaloidotomy opening in three eyes and the haptic of intraocular lens blocking the hyaloidotomy opening in one eye. Recurrence of aqueous misdirection even after vitrectomy may be related to obstruction of aqueous flow through the communication created, either by intraocular lens or fibrin. Treatment of this condition involves restoring aqueous flow to the anterior chamber from the anterior vitreous by treating the cause, and most often the YAG laser hyaloidotomy/membranotomy is successful in relieving the condition.

Estimation of the melatonin suppression index through clear and yellow-tinted intraocular lenses.

PURPOSE: To estimate the melatonin suppression index (MSI), which may reflect the nonvisual photoreception function, through commercially available foldable, clear and yellow-tinted intraocular lenses (IOLs). METHODS: The MSIs for 13 IOL models (6 clear IOLs, 7 yellow-tinted IOLs) with three lens powers were calculated based on previously reported data about the melatonin suppression spectrum, spectral intensity of a 20-W white fluorescent lamp and spectral transmission of IOLs in wavelengths from 300 to 800 nm. The models tested were the SA60AT and SN60AT (Alcon Japan); the VA-60BBR, YA-60BBR, and NM-1 (Hoya); the AU6K and AN6K (Kowa); the N4-18B and N4-18YG (Nidek); the X-60 and NX-60 (Santen); and the KS-3Ai and KS-AiN (Staar Japan). RESULTS: The MSIs of the clear IOLs ranged from 1.12 to 1.18 mW cm(-2) sr(-1) and those of the yellow-tinted IOLs from 0.74 to 1.01 mW cm(-2) sr(-1). All yellow-tinted IOLs had significantly lower MSIs (P < 0.0001-0.0021) than the clear IOLs; the %MSI cutoff values for yellow-tinted IOLs compared to the clear IOLs were 11.4-36.2 %. The MSIs of the six clear IOLs did not differ based on lens powers (P = 0.2159-0.6144). Except for one IOL model, all yellow-tinted IOLs had a lower MSI with higher lens powers compared to those with lower lens powers (P < 0.0001-0.0055). Compared to phakic eyes (MSI, 1.03 mW cm(-2) sr(-1)), the MSIs of the clear IOLs were higher (%MSI cutoff, -14.6 to -8.4 %), whereas those of the yellow-tinted IOLs were lower (2.6-28.1 %). Compared to aphakic eyes (MSI, 1.21 mW cm(-2) sr(-1)), the MSIs of the clear (2.1-7.4 %) and yellow-tinted (16.7-38.6 %) IOLs were lower. CONCLUSIONS: Yellow-tinted IOLs absorb more circadian rhythm-associated light than clear IOLs. The difference in the lens power is significantly related to the MSI value in some yellow-tinted IOLs. To correlate the current data with the clinical relevance of these findings, the percent loss of the MSI leading to a circadian rhythm disorder needs to be clarified.

Effect of age and other factors on macular pigment optical density measured with resonance Raman spectroscopy.

BACKGROUND: Macular pigment is a defense system against phototoxic damage of the retina by visible light. It is still under debate whether or not macular pigment optical density (MPOD) levels decline with age, because the age effect varied depending on the technique used to measure MPOD levels. Resonance Raman spectroscopy (RRS) is an objective method to measure MPOD, and studies using RRS showed a drastic age-related decline of MPOD levels; however, since RRS measurements are influenced by cataracts, it has been argued that the age-related decline of RRS measurements is an artifact from lens changes in aged subjects. In the present study, MPOD levels were measured with RRS in pseudophakic eyes, and the effects of age and other factors on MPOD levels were investigated. METHODS: The subjects included 144 patients with no fundus disorders who received cataract surgery with untinted intraocular lens implantation. MPOD levels were measured in 144 eyes using integral RRS 1 day post surgery. Factors potentially associated with MPOD levels such as age, gender, smoking habits, body mass index, diabetes, glaucoma, axial length, pupil diameter, spherical equivalent refractive error, and foveal thickness were examined by multiple regression analysis. RESULTS: The macular pigment RRS levels ranged from 776 to 11,815 Raman counts, with an average level of 4,375 ± 1,917 (standard deviation [SD]) Raman counts. Multiple regression analysis revealed that age and axial length were significantly correlated with low MPOD values (regression coefficient of -59 for age and -404 for axial length, respectively). No significant correlations were observed for other factors. CONCLUSIONS: After removing the potentially confounding effect of age-related lens yellowing on the RRS measurements, age remained a significant patient parameter for lowered MPOD levels. MPOD levels were found to decline by more than 10 % each decade. Axial length was also a negative predictor of MPOD levels. Since the present study included only patients aged 50 years and older, the effects of age and other factors on MPOD levels for younger subjects remain unknown.

Monocyte chemotactic protein-1 level in the aqueous humour as a prognostic factor for the outcome of trabeculectomy.

BACKGROUND: The aim of this study was to elucidate the effects of the aqueous humour monocyte chemotactic protein-1 level on the surgical outcome of trabeculectomy in cases of phakic glaucoma. DESIGN: Retrospective study. PARTICIPANTS: Fifty-three cases of open-angle glaucoma. METHODS: At the time of trabeculectomy, aqueous humour samples were collected before any incisions were made. The monocyte chemotactic protein-1 level was then determined by immunoassay. The Cox proportional hazards test was used to analyse the clinical factors related to failure of trabeculectomy. Subsequently, the success probability was calculated by Kaplan-Meier analysis and cumulative success probabilities were analysed by the log-rank test. MAIN OUTCOME MEASURES: Probability of success. RESULTS: In 30 phakic glaucoma and 23 pseudophakic glaucoma cases, the mean monocyte chemotactic protein-1 levels in aqueous humour were 1165.2 and 2152.9 pg/mL, respectively; the difference was statistically significant (P < 0.0001). Univariate analysis showed that the outcomes of surgery were correlated with the monocyte chemotactic protein-1 level, but not with age, gender, diagnosis of exfoliation glaucoma, pseudophakic status or pretrabeculectomy intraocular pressure. Subsequent multivariate analysis revealed that only the aqueous humour monocyte chemotactic protein-1 level was significantly correlated with the outcomes of trabeculectomy (P = 0.043). Among the 30 phakic glaucoma eyes, the success probabilities after trabeculectomy were significantly different between the high and low monocyte chemotactic protein-1 groups (P = 0.018). CONCLUSION: In open-angle glaucoma patients, the monocyte chemotactic protein-1 level is a prognostic factor for the results of trabeculectomy.

Role of corneal collagen cross-linking in pseudophakic bullous keratopathy: a clinicopathological study.

OBJECTIVE: To evaluate the clinical and histopathologic changes induced by collagen cross-linking (CXL) in pseudophakic bullous keratopathy (PBK). DESIGN: Randomized, prospective, interventional study. PARTICIPANTS: Twenty-four patients with PBK were included in the study. METHODS: Twenty-four patients with PBK underwent CXL followed by keratoplasty at 1 or 3 months. Twelve patients underwent penetrating keratoplasty 1 month after CXL (group A) and the remaining 12 patients underwent penetrating keratoplasty 3 months after CXL (group B). The main outcome measures were assessed at 1 week and 1 month for all patients and at 3 months for 12 patients only. The corneal buttons underwent histopathologic and immunofluorescence evaluation. MAIN OUTCOME MEASURES: Visual acuity, ocular discomfort (tearing, redness, pain), corneal haze, central corneal thickness, histopathologic evaluation, and immunofluorescent microscopy. RESULTS: Mean visual acuity showed a significant improvement after CXL, from 1.925 ± 0.173 before surgery to 1.75±0.296 at 1 month after surgery (P = 0.010), but deteriorated to 1.81 ± 0.23 at 3 months. Symptomatic relief after CXL was at a maximum at 1 month, with a worsening trend at 3 months. Eighteen patients showed a reduction in corneal haze 1 month after CXL. The effect was maintained in 9 of 12 patients at 3 months. The mean central corneal thickness decreased significantly from 846.46 ± 88.741 to 781.0 ± 98.788 µm at 1 month (P<0.01) after CXL, but increased to 805.08±136.06 µm at 3 months. Immunofluorescence microscopy revealed anterior stromal compaction in 7 of 12 patients (58.3%) in group A and in 5 of 12 patients (41.6%) in group B. Staining of keratocyte nuclei with 4',6-diaminido-2-phenylindole dihydrochloride (Molecular Probes, Carlsband, CA) revealed a relative uniform distribution throughout the stroma. CONCLUSIONS: Collagen cross-linking causes symptomatic relief and a decrease in central corneal thickness and anterior stromal compaction in PBK. However, the effect decreases with time and depends on disease severity.

Aqueous flare is increased in patients with clinically significant cystoid macular oedema after cataract surgery.

BACKGROUND: To analyse the relationship of clinically significant cystoid macular oedema (CME after phacoemulsification to blood-aqueous barrier breakdown as determined by aqueous flare, visual acuity and retinal thickness in optical coherence tomography (OCT). MATERIALS AND METHODS: 30 eyes of 30 consecutive patients with clinically significant CME and vision loss were included. 46 pseudophakic and 45 phakic eyes without CME served as controls. Clinical data included age, gender, best-corrected visual acuity (BCVA) and spectral domain OCT volume scans. Retinal thickness measuring of the foveal central subfield was determined. Aqueous flare was measured quantitatively with the Kowa FM-500 Laser Flare-Cell Meter. RESULTS: Patients with CME had significantly higher flare values compared with pseudophakic patients (p<0.0001). For patients with CME, aqueous flare values correlated significantly with BCVA (Spearman rs=0.4, p=0.041), while there was no correlation with retinal thickness. Using flare values to predict CME, receiver operating characteristic analysis returned an area under the curve of 0.976. CONCLUSIONS: Aqueous flare as a marker for inflammation and breakdown of the blood-retinal barrier is increased in patients with CME after cataract surgery.

Simultaneous increases in multiple proinflammatory cytokines in the aqueous humor in pseudophakic glaucomatous eyes.

PURPOSE: To evaluate cytokine and growth factor levels in the aqueous humor in patients with open-angle glaucoma (OAG). SETTING: Kumamoto University Hospital, Kumamoto, Japan. DESIGN: Cross-sectional cohort study. METHODS: Aqueous humor samples were collected from cataract cases and OAG cases. Aqueous levels of cytokines and growth factors were determined by multiplex immunoassay. The data were analyzed using the Tukey-Kramer honestly-significant-difference test and multiple regression analyses. RESULTS: The study evaluated 52 cataract cases and 73 OAG cases. In the cataract cases, the mean interleukin (IL)-6, IL-8, monocyte chemotactic protein (MCP)-1, tumor necrosis factor-α, epidermal growth factor, vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF)-AA, PDGF-AB/BB, and VEGF levels (all pg/mL) were 21.4, 4.6, 829.4, 0.8, 0.5, 33.8, 1.6, and 77.9, respectively. In 23 phakic primary OAG (POAG) and 26 phakic exfoliation glaucoma cases, the corresponding values were 15.1 and 8.3, 15.2 and 12.3, 1142.5 and 1253.9, 0.3 and 0.5, 1.5 and 1.4, 57.7 and 58.0, 2.5 and 3.3, 37.4 and 59.7, respectively. In pseudophakic OAG cases, the IL-8 levels for exfoliation glaucoma (P=.0002) and MCP-1 for POAG (P=.0008) and exfoliation glaucoma (P<.0001) were significantly different compared with phakic OAG. Interleukin-6, IL-8, and MCP-1 levels were correlated (P<.0001). Multiple regression analyses showed the highest association of pseudophakic status with IL-8 and MCP-1 levels (P=.0002 and P<.0001, respectively). CONCLUSION: The OAG patients, especially those with pseudophakic eyes, had simultaneous cytokine level increases, suggesting the aqueous humor microenvironment is altered in pseudophakic glaucomatous eyes. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Histological evaluation of corneal scar formation in pseudophakic bullous keratopathy.

PURPOSE: To evaluate histological changes in the corneal stroma in pseudophakic bullous keratopathy. METHODS: Twenty-eight patients (28 eyes) with pseudophakic bullous keratopathy underwent therapeutic penetrating keratoplasty at Shandong Eye Institute between January 2006 and November 2011. The patients were divided into two groups according to the duration of bullous keratopathy (<1.0 year group or >1.0 year group), and three buttons from enucleated eyes with choroidal melanoma served as a control. In vivo confocal microscopy examination, hematoxylin-eosin, Masson's trichrome stain and Van Gieson staining were used for microscopic examination. The histological evaluation and scoring of the buttons for morphological changes, including the degree of stromal scars, neovascularization and inflammatory cells within the corneal buttons, were compared. To study the underlying mechanism, connective tissue growth factor (CTGF) and TGF-ß immunohistochemistry were performed. RESULTS: Confocal microscopy examination and histological evaluation and scoring of the buttons showed that compared with the <1.0 year group, stromal scars, neovascularization and inflammatory cells were more severe in the >1.0 year group (P<0.05). There was an increase in CTGF- and TGF-ß1-positive stromal cells in the >1.0 year group. CONCLUSIONS: During the progression of pseudophakic bullous keratopathy, stromal scars occurred more often in the patients that had a longer duration of disease. Cytokines such as CTGF and TGF-ß1 may play a role in this pathological process and deserve further investigation.

Macular pigment changes in pseudophakic eyes quantified with resonance Raman spectroscopy.

PURPOSE: We examined changes in macular pigment optical density (MPOD) levels after cataract surgery and compared the MPOD between eyes with clear intraocular lenses (IOLs) and yellow-tinted IOLs. DESIGN: Prospective, comparative case series. PARTICIPANTS: The MPOD levels were measured in 480 eyes of 337 patients after cataract surgery. Among them, the data from 259 eyes (clear IOL group, 121 eyes; yellow-tinted IOL group, 138 eyes) of 259 Japanese patients were selected for statistical analyses on the basis of the inclusion criteria: a postoperative visual acuity (VA) of ≥0.8 and no fundus diseases. Only 1 eye of each patient was enrolled. Patients provided informed consent to participate in this study on the basis of the approval of the institutional review board before surgery. METHODS: The patients selected the type of IOL to be implanted. The MPOD levels were measured using resonance Raman spectroscopy on day 1 (baseline value); months 1, 3, and 6; and years 1 and 2 postoperatively. MAIN OUTCOME MEASURES: The difference in MPOD levels between the IOL groups was analyzed by unpaired t tests. The following parameters were analyzed by multiple regression analysis: age, gender, body mass index (BMI), smoking history, glaucoma, diabetes, preoperative VA, preoperative refractive error, and IOL power and type. RESULTS: We found no significant differences in the baseline characteristics between the 2 groups. Until 6 months postoperatively, the MPOD levels did not differ significantly between the groups. However, from 1 year onward, the levels were significantly higher in the yellow-tinted IOL group compared with the clear IOL group. By multiple regression analysis, 1 day postoperatively, older age and diabetes were correlated with lower MPOD levels; 1 year postoperatively and thereafter, however, lower MPOD levels were correlated with clear IOLs. CONCLUSIONS: Cataract surgery with clear IOLs induced a greater decrease in macular pigment levels compared with yellow-tinted IOLs during a longer follow-up period. These findings agreed with observations that excessive light exposure is associated inversely with MPOD, because clear IOLs transmit higher intensities of blue light than yellow-tinted IOLs.

Oxygen distribution in the human eye: relevance to the etiology of open-angle glaucoma after vitrectomy.

PURPOSE: Vitrectomy, when followed by cataract surgery, increases the risk of open-angle glaucoma. This study was conducted in patients to determine whether these procedures are associated with increased exposure of the trabecular meshwork to oxygen. METHODS: Oxygen distribution was recorded with a fiberoptic probe in patients undergoing surgery for cataract, glaucoma, or retinal disease. pO(2) was measured beneath the central cornea, in the mid-anterior chamber, and in the anterior chamber angle. In patients who were pseudophakic or were scheduled for cataract extraction, pO(2) was also measured in the posterior chamber and near the lens. RESULTS: Eyes with no previous cataract or vitrectomy surgery had steep oxygen gradients in the aqueous humor between the cornea and lens. pO(2) was low in the posterior chamber and near the lens. Previous vitrectomy was associated with significantly increased pO(2) in the posterior chamber. Eyes with previous cataract surgery had significantly elevated pO(2) only in the posterior chamber and in front of the intraocular lens (IOL). Eyes that had both vitrectomy and previous cataract surgery had increased pO(2) in the posterior chamber, anterior to the IOL, and in the anterior chamber angle. pO(2) in the posterior chamber and the anterior chamber angle correlated strongly. CONCLUSIONS: Oxygen metabolism by the lens and cornea establishes oxygen gradients in the anterior segment. Vitrectomy and cataract surgery increase pO(2) in the anterior chamber angle, potentially damaging trabecular meshwork cells. We propose that oxygen levels in the anterior chamber angle are strongly influenced by oxygen derived from the ciliary body circulation.

Spectral analysis and comparison of mineral deposits forming in opacified intraocular lens and senile cataractous lens.

This preliminary report was attempted to compare the chemical components of mineral deposits on the surfaces of an opacified intraocular lens (IOL) and a calcified senile cataractous lens (SCL) by vibrational spectral diagnosis. An opacified intraocular lens (IOL) was obtained from a 65-year-old male patient who had a significant decrease in visual acuity 2-years after an ocular IOL implantation. Another SCL with grayish white calcified plaque on the subcapsular cortex was isolated from a 79-year-old male patient with complicated cataract after cataract surgery. Optical light microscope was used to observe both samples and gross pictures were taken. Fourier transform infrared (FT-IR) and Raman microspectroscopic techniques were employed to analyze the calcified deposits. The curve-fitting algorithm using the Gaussian function was also used to quantitatively estimate the chemical components in each deposit. The preliminary results of spectral diagnosis indicate that the opacified IOL mainly consisted of the poorly crystalline, immature non-stoichiometric hydroxyapatite (HA) with higher content of type B carbonated apatites. However, the calcified plaque deposited on the SCL was comprised of a mature crystalline stoichiometric HA having higher contents of type A and type B carbonate apatites. More case studies should be examined in future.

Magnetic resonance imaging of the anteroposterior position and thickness of the aging, accommodating, phakic, and pseudophakic ciliary muscle.

PURPOSE: To quantify accommodative and age-related changes in the anteroposterior position and thickness of the ciliary muscle in phakic and pseudophakic eyes. SETTING: Department of Surgery/Bioengineering, UMDNJ-Robert Wood Johnson Medical School, Piscataway; Institute of Ophthalmology and Visual Science UMDNJ-New Jersey Medical School, Newark, New Jersey; MRI Research, Inc., Middleburg Heights, Ohio, USA. METHODS: Magnetic resonance images were taken of phakic and pseudophakic eyes. RESULTS: The cohort comprised 32 phakic volunteers and 8 volunteers with a monocular intraocular lens (IOL) aged 22 to 91 years. No anteroposterior accommodative movement of the ciliary muscle apex occurred in either group. The muscle moved closer to the cornea with advancing age in phakic eyes; IOL implantation returned the muscle to a youthful position. An age-dependent increase in ciliary muscle anteroposterior thickness occurred that was not mitigated by IOL implantation. Muscle thickness increased with accommodation in only phakic eyes. CONCLUSIONS: Presbyopia-correction strategies cannot rely on accommodative anterior movement of the ciliary muscle. Forces on the uvea by crystalline lens-pupillary margin contact may increase with accommodation and lens growth, producing accommodative and age-dependent increases in muscle thickness and significant age-dependent anterior muscle displacement. Intraocular lens implantation removed these forces, allowing choroidal elasticity to restore the muscle to a youthful position; however, the increase in thickness was permanent and likely due to an age-dependent increase in connective tissue. This supports the geometric theory of presbyopia development and that the mechanical forces in human accommodation and presbyopia are very different from those in the rhesus monkey model.