Association Between Oral Metformin Use and the Development of Age-Related Macular Degeneration in Diabetic Patients: A Systematic Review and Meta-Analysis.

Purpose: Metformin is a biguanide derivative that is commonly used for the treatment of diabetes mellitus (DM). It demonstrates antioxidative, anti-inflammatory, and antiangiogenic activity within the ocular tissue and thus may be implicated in the treatment of age-related macular degeneration (AMD). However, epidemiological studies have shown conflicting results. Methods: The Ovid MEDLINE/Embase, Cochrane Library, and Web of Science databases were systematically searched from inception through August 3, 2022. Studies reporting the association between metformin use and odds of AMD were enrolled. Adjusted odds ratios (ORs) of AMD were extracted and pooled with random-effects model meta-analysis. Subgroup analyses based on AMD subtypes, ethnicity, study design, sex, and confirmation of AMD diagnosis were conducted. Results: A total of 9 observational studies with 1,446,284 participants were included in the analysis. The meta-analysis showed that metformin use was associated with a significant reduction in the odds of AMD (pooled ORs = 0.81, 95% confidence interval [CI] = 0.70-0.93). Subgroup analyses revealed that metformin use was not significantly associated with dry or wet AMD. Black (pooled ORs = 0.61, 95% CI = 0.58-0.64) and Hispanic populations (pooled ORs = 0.85, 95% CI = 0.81-0.89) demonstrated significantly lower odds of AMD. Conclusions: This systematic review and meta-analysis found that patients with DM with metformin usage were at lower odds of developing AMD. Future prospective clinical trials are needed to confirm this association.

Equivalent legibility font size for traditional Chinese character compared to early treatment diabetic retinopathy study near visual acuity.

PURPOSES: To investigate the legibility of a standardized logarithmic print size of traditional Chinese (TC) characters and compare it with Early Treatment Diabetic Retinopathy Study (ETDRS) near chart. MATERIALS AND METHODS: A total of 1243 commonly used TC characters were chosen and divided into three groups according to its stroke complexity: Group A with 2-9 strokes, Group B with 10-17 strokes, and Group C with 18-25 strokes. For each group of characters, near charts were created using randomly chosen characters arranged in decreasing logarithmic size. In a well-illuminated room, healthy controls were fully corrected to test both ETDRS near chart and our set of TC near charts. The smallest legible font sizes (SLFS) in TC near charts were recorded and analyzed. RESULTS: Forty-two healthy eyes (21 participants) (age 29 ± 8.9 years old) were included. The mean near best-corrected visual acuity (nBCVA) in ETDRS chart was 0.06 ± 0.05 logMAR. We found that the mean SLFS in TC charts (0.33 ± 0.09 logMAR) was significantly larger than the nBCVA in ETDRS chart (P < 0.001). The SLFS of Group B and the SLFS of Group C was significantly larger than that of Group A (P < 0.001). CONCLUSION: According to our results, to recognize TC characters, normal-sight readers need a 0.22-0.30 logMAR (1.7-2.0 fold) enlargement of the acuity size measured by ETDRS near chart. The low-stroke TC charts may provide a new method to assess the postsurgical outcomes for comparable functional visual acuity in reading TC characters.

Anterior Migration of Triamcinolone Acetonide after Posterior Subtenon Injection for Macular Edema Predisposes to Intraocular Pressure Elevation.

PURPOSE: To evaluate the effect of anterior migration of triamcinolone acetonide on intraocular pressure (IOP) elevation after posterior subtenon injection of triamcinolone acetonide (PSTA) for macular edema. METHODS: One hundred and ten eyes from 89 patients who received PSTA for macular edema were prospectively enrolled. The extent of anterior migration of triamcinolone acetonide was recorded immediately after the injection. If TA particles were visible in the subtenon space (or subconjunctival space), it was recorded as "anterior subtenon migration" (or "anterior subconjunctival migration"). The correlation between anterior migration of triamcinolone acetonide and severe IOP elevation, which was defined as an increase of 8 mm Hg or more in IOP, was evaluated. RESULTS: A total of 159 PSTAs were given to 110 eyes. After PSTA, anterior subtenon migration occurred in 70.4% and anterior subconjunctival migration occurred in 12.0% of injection. Severe IOP elevation occurred in 7.1% of those without anterior migration, in 25.9% of those with anterior subtenon migration, and in 31.6% of those with anterior subconjunctival migration after PSTA (P = .052). Compared to those without anterior migration of triamcinolone acetonide, the hazard ratio for severe IOP elevation was 3.307 in those with anterior subtenon migration (P = .12) and 5.289 in those with anterior subconjunctival migration (P = .042). CONCLUSIONS: Anterior migration of triamcinolone acetonide after PSTA predisposes eyes to severe IOP elevation. Careful injection to restrict the triamcinolone particle within the subtenon space and behind the equator may lower the rate of IOP elevation after PSTA.

Short-term refractive and ocular parameter changes after topical atropine.

PURPOSE: The purpose of this study is to explore short-term refractive and ocular parameter changes and their correlations after cycloplegia with atropine. METERIALS AND METHODS: This is a prospective clinical trial that enrolled 96 eyes of 96 participants (mean age, 8.5 ± 2.1 years). Spherical equivalent refractive error (SER), axial length (AL), mean keratometric value (mean-K), anterior chamber depth (ACD), and intraocular pressure (IOP) were measured at baseline and 1 week after topical use of 0.125% atropine. Postcycloplegic changes of refractive error and ocular parameters were evaluated, and their correlations were analyzed with multiple linear regression models. RESULTS: After topical atropine use, the mean AL decreased by 0.016 mm (P = 0.008), and the mean ACD increased by 0.58 mm (P < 0.0001). There was no significant change in the Mean-K or IOP. Eighty-two eyes (85%) had an emmetropic or hyperopic shift, and 14 (15%) had a myopic shift. Those with an emmetropic or hyperopic shift had their mean AL shortened by 0.023 mm, whereas the eyes with myopic shifts had their mean AL lengthened by 0.026 mm (P = 0.003). Change in SER was negatively correlated with change in AL (-2.57 D for an increase of 1 mm in AL, P < 0.001) and positively correlated with change in ACD (+0.96 D for an increase of 1 mm in ACD, P = 0.013). CONCLUSION: Most eyes had emmetropic or hyperopic changes after short-term topical atropine use, and AL shortening and anterior chamber deepening both contributed to the hyperopic changes. Meanwhile, myopic change may be observed in some eyes (15%), which were related to transient AL elongation but not invalid myopic control. This encouraged clinicians to sustain the atropine treatment for a longer period before switching to other modalities for myopic control in clinical practice.The clinical trial registration number NCT03839888 (clinicaltrials.gov).

Ocular hypertension and severe intraocular pressure elevation after posterior subtenon injection of triamcinolone acetonide for various diseases.

AIM: To evaluate and compare the incidences of ocular hypertension and severe intraocular pressure (IOP) elevation after posterior subtenon injection of triamcinolone acetonide (PSTA) for various diseases. METHODS: Totally 179 eyes that had received PSTA for diabetic macular edema (n=108), pseudophakic cystoid macular edema (n=20), branch retinal vein occlusion (n=16), central retinal vein occlusion (CRVO, n=14), choroidal neovascularization (n=14) or noninfectious uveitis (n=7) were retrospectively enrolled. The primary outcomes included ocular hypertension defined as an IOP>21 mm Hg, and severe IOP elevation defined as a rise of 10 mm Hg or more in IOP compared with baseline. Cox regression models were used to analyze the hazard ratios (HRs) among different diseases. RESULTS: After PSTA, the mean IOPs from month 1 to month 6 all significantly increased (P<0.05). Ocular hypertension occurred in 30.7% of eyes (median time: 8wk), and severe IOP elevation occurred in 16.2% of eyes (median time: 9wk). Patients receiving PSTA for CRVO or uveitis had a significantly higher risk for ocular hypertension (HR=3.049, P=0.004 for CRVO; HR=5.464, P=0.019 for uveitis) and severe IOP elevation (HR=2.913, P=0.034 for CRVO; HR=7.650, P=0.009 for uveitis). CONCLUSION: IOP significantly increases within 6mo after PSTA, with the onset of ocular hypertension happening mostly at 2 to 3mo. Patients of CRVO or noninfectious uveitis have a higher risk of ocular hypertension or severe IOP elevation after PSTA and should be monitored for IOP more carefully.

Correlation of pterygium severity with IQ-domain GTPase-activating protein 1 (IQGAP1) and mast cells.

IQ-domain GTPase-activating protein 1 (IQGAP1) is a multidomain scaffold protein that is involved in cytoskeleton dynamics and tumor metastasis. Although the role of IQGAP1 in various cancers had been reported, the function of IQGAP1 in pterygium has not been studied. In this study, surgically excised pterygium and control conjunctival tissue from cataract patients were analysed by immunohistochemistry, confocal microscopy, and Western blot for IQGAP1 expression, mast cell counts, and microvascular count. Pterygium was clinically divided into mild and severe types according to Tan's classification and Kim's criteria based on translucency and vascularity of the tissue. Greater clinical severity of pterygium was associated with higher expression of IQGAP1 expression. Compared to normal conjunctival tissue, severe pterygium had significantly higher IQGAP1 expression (P = 0.005), which strongly correlated to the number of microvessels (P = 0.003) and mast cells (P = 0.01). Confocal microscopy revealed IQGAP1 colocalization with mast cell and CD31. IQGAP1 expression was higher in the pterygium body compared to the head. In conclusion, the level of IQGAP1 expression was found to be correlated to the clinical severity of pterygium. Mast cells were identified in pterygium and is suspected to be involved in promoting fibrovascular invasion.

Neuroprotective Effects of Collagen-Glycosaminoglycan Matrix Implantation following Surgical Brain Injury.

BACKGROUND: Neurological deficits following neurosurgical procedures are inevitable; however, there are still no effective clinical treatments. Earlier reports revealed that collagen-glycosaminoglycan (CG) matrix implantation promotes angiogenesis, neurogenesis, and functional recovery following surgical brain injury (SBI). The present study was conducted to further examine the potential neuroprotective effects of collagen-glycosaminoglycan (CG) matrix implantation following neurosurgery. METHODS: CG implantation was performed in the lesion cavity created by surgical trauma. The Sprague-Dawley rat model of SBI was used as established in the previous study by the author. The rats were divided into three groups as follows: (1) sham (SHAM), (2) surgery-induced lesion cavity (L), and (3) CG matrix implantation following surgery-induced lesion cavity (L+CG). Proinflammatory (tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells)) and anti-inflammatory (IL-10 and granulocyte-macrophage colony-stimulating factor (GMCSF)) cytokine expression was evaluated by enzyme-linked immunosorbent assays. Microglial activation was evaluated by immunohistochemistry, and the neuroprotective effect of CG matrix implantation was evaluated by an immunohistochemical study of microglia ED-1 and IBA-1 (activated microglia) and myeloperoxidase (MPO) and by the analysis of IL-6, IL-10, TNF-α, NF-κB, and GMCSF cytokine levels. Apoptosis was also assessed using a TUNEL assay. RESULTS: The results showed that CG matrix implantation following surgically induced lesions significantly decreased the density of ED-1, IBA-1, and MPO (activated microglia). The tissue concentration of proinflammatory cytokines, such as TNF-α, IL-6, and NF-κB was significantly decreased. Conversely, the anti-inflammatory cytokines GMCSF and IL-10 were significantly increased. CONCLUSIONS: Implantation of the CG matrix following SBI has neuroprotective effects, including the suppression of microglial activation and the production of inflammatory-related cytokines.

The healing effect of the collagen-glycosaminoglycan copolymer on corneal thinning.

BACKGROUND: To study the healing processes of partial thickness wounds in the adult rabbit cornea after grafting a porous collagen-glycosaminoglycan copolymer matrix (CG). METHODS: In this study, the regeneration of surgically-induced rabbit corneal defect implanted with CG was investigated. The corneal partial thickness wound was created by 7.5 mm trephine. The wound was implanted with CG. Effects on wound healing was analyzed using clinical data on epithelial migration and corneal thickness, and histological data on collagen and alpha smooth muscle actin distribution. RESULTS: Compared with control group, CG induced a relatively severe inflammatory reaction in grafted cornea until the CG matrix was completely degraded. The new vessel ingrowth and stromal regeneration maintained the corneal thickness. The grafted cornea was significantly thicker (P < 0.001) than the control group. On day 90, the corneal opacity score of the control group was one and the grafted cornea was two. CONCLUSION: CG copolymer matrix can successfully repair the damaged corneal stroma by injury, and regain its thickness. However, CG matrix induced inflammatory healing process thus causing mild corneal haziness and neovascularization.

Enhancement of matrix metalloproteinases 2 and 9 accompanied with neurogenesis following collagen glycosaminoglycan matrix implantation after surgical brain injury.

Surgical brain injury may result in irreversible neurological deficits. Our previous report showed that partial regeneration of a traumatic brain lesion is achieved by implantation of collagen glycosaminoglycan (CGM). Matrix metalloproteinases (MMPs) may play an important role in neurogenesis but there is currently a lack of studies displaying the relationship between the stimulation of MMPs and neurogenesis after collagen glycosaminoglycan implantation following surgical brain trauma. The present study was carried out to further examine the expression of MMP2 and MMP9 after implantation of collagen glycosaminoglycan (CGM) following surgical brain trauma. Using the animal model of surgically induced brain lesion, we implanted CGM into the surgical trauma. Rats were thus divided into three groups: (1) sham operation group: craniotomy only; (2) lesion (L) group: craniotomy + surgical trauma lesion; (3) lesion + CGM (L + CGM) group: CGM implanted following craniotomy and surgical trauma lesion. Cells positive for SOX2 (marker of proliferating neural progenitor cells) and matrix metalloproteinases (MMP2 and MMP9) in the lesion boundary zone were assayed and analyzed by immunofluorescence and ELISA commercial kits, respectively. Our results demonstrated that following implantation of CGM after surgical brain trauma, significant increases in MMP2+/SOX2+ cells and MMP9+/SOX2+ cells were seen within the lesion boundary zone in the L + CGM group. Tissue protein concentrations of MMP2 and MMP9 also increased after CGM scaffold implantation. These findings suggest that implantation of a CGM scaffold alone after surgical brain trauma can enhance the expression of MMP2 and MMP9 accompanied by neurogenesis.

Optic Disc Parameters of Myopic Children with Atropine Treatment.

PURPOSE: To characterize optic disc parameters, retinal nerve fiber layer thickness (RNFLT), and the intraocular pressure (IOP) of myopic children under continual topical 0.25% atropine treatment. METHODS: From October 1, 2010 to September 31, 2011, 67 eyes of 35 myopic children were recruited. The children were treated with 0.25% atropine nightly for myopia control. Visual acuity, refraction, IOP, axial length (AL, IOL Master), RNFLT, and optic disc parameters (Stratus OCT) were measured at enrollment and every 2 months. All patients had at least 1 year of follow-up. RESULTS: Enrolled children had a mean age of 10.3 ± 2.4 years (5-15 years). Of the 67 studied eyes, the mean spherical equivalent (SE) was -2.60 ± 1.58 diopters (D) (-6.75--0.5 D). Under the treatment of 0.25% atropine, myopia increased by 0.53 ± 0.10D per year (P < 0.0001), and AL elongated by 0.245 ± 0.042 mm per year (P < 0.0001). No significant change was noted in the IOP and optic nerve parameters including peripapillary RNFLT, areas of optic disc, cup and rim, or cup/disc ratio over the follow-up period during atropine treatment (P > 0.05). CONCLUSIONS: 0.25% Atropine treatment for myopia control did not significantly affect the IOP, optic nerve parameters, and RNFLT in children over a mean of 15.2 ± 2.4 months treatment and follow-up. 0.25% Atropine is a relatively safe option for myopia control.

Prognostic factors of short-term outcomes of intravitreal ranibizumab in diabetic macular edema.

AIM: To evaluate the prognostic factors for short-term visual and anatomical improvement of intravitreal ranibizumab (IVR) for diabetic macular edema (DME). METHODS: Fifty-one eyes from 35 patients that received three consecutive monthly IVR for DME with moderate visual loss were retrospectively recruited; all cases had their baseline best-corrected visual acuity (BCVA) between 20/400 and 20/40. BCVA and central subfield thickness (CST) at baseline and month 3 were collected. Linear mixed models were used to evaluate the prognostic factors for visual and anatomical improvement at month 3. RESULTS: Younger age, poorer baseline BCVA and proliferative diabetic retinopathy (PDR) were correlated with better visual improvement at month 3 (P=0.002, 0.0001 and 0.007, respectively). Thicker CST and the presence of subretinal fluid at baseline were correlated with a greater reduction in CST (P<0.0001 and P=0.018, respectively). The presence of epiretinal membrane or previous posterior subtenon injection of triamcinolone acetonide (PSTA) were associated with a smaller reduction in CST (P=0.029 and 0.018, respectively), but had no significant effects in visual improvement at month 3 (P>0.05 for both). CONCLUSION: For eyes with DME and moderate visual loss, those with younger age, poorer baseline BCVA or PDR tend to have better visual improvement after three consecutive monthly IVR. Epiretinal membrane or previous PSTA result in less resolution of CST, but do not significantly affect visual improvement.

Subtenon Triamcinolone Acetonide Removal for Uncontrolled Ocular Hypertension After Posterior Subtenon Injection of Triamcinolone Acetonide.

PURPOSE: To report the control of intraocular pressure (IOP) after removal of subtenon triamcinolone acetonide (TA) plaques in patients with uncontrolled ocular hypertension after posterior subtenon injection of triamcinolone acetonide (PSTA) and to evaluate the factors associated with rapid IOP normalization after subtenon TA removal. MATERIALS AND METHODS: Data from 8 eyes of 7 patients receiving excision of subtenon TA plaques for uncontrolled ocular hypertension after PSTA in 1 hospital from June 2010 to December 2012 were retrospectively collected. The percentage of IOP lowering on postoperative day 1 and the time to IOP normalization after subtenon TA removal were reported. Pearson correlation analysis was used to analyze the factors for rapid IOP normalization after subtenon TA removal. RESULTS: The IOP lowering on postoperative day 1 ranged from 12% to 75%. All cases achieved IOP normalization within a mean of 2.5±1.9 days (range, 1 to 5 d) after subtenon TA removal. Fewer kinds of antiglaucoma agents used before subtenon TA removal was associated with greater IOP lowering on postoperative day 1 (P=0.01) and more rapid return to normal IOP (P=0.01). Older age and more time from PSTA to ocular hypertension were both correlated with shorter time to achieve IOP normalization after operation (P=0.01 and 0.02, respectively). CONCLUSIONS: In medically uncontrolled ocular hypertension after PSTA, excision of subtenon TA plaques provided IOP normalization as rapidly as 1 to 5 days. Fewer preoperative antiglaucoma agents, older age, and more time from PSTA to ocular hypertension were correlated with more rapid IOP normalization after subtenon TA removal.

Collagen-glycosaminoglycan matrix implantation promotes angiogenesis following surgical brain trauma.

Surgical brain injury (SBI) is unavoidable during many neurosurgical procedures intrinsically linked to postoperative neurological deficits. We have previously demonstrated that implantation of collagen glycosaminoglycan (CG) following surgical brain injury could significantly promote functional recovery and neurogenesis. In this study we further hypothesized that this scaffold may provide a microenvironment by promoting angiogenesis to favor neurogenesis and subsequent functional recovery. Using the rodent model of surgical brain injury as we previously established, we divided Sprague-Dawley male rats (weighting 300-350 g) into three groups: (1) sham (2) surgical injury with a lesion (L), and (3) L with CG matrix implantation (L + CG). Our results demonstrated that L + CG group showed a statistically significant increase in the density of vascular endothelial cells and blood vessels over time. In addition, tissue concentrations of angiogenic growth factors (such as VEGF, FGF2, and PDGF) significantly increased in L + CG group. These results suggest that implantation of a CG scaffold can promote vascularization accompanied by neurogenesis. This opens prospects for use of CG scaffolds in conditions such as brain injury including trauma and ischemia.

Randomized, double-blind, controlled study to evaluate the effect of vidian nerve cauterization on lacrimation.

BACKGROUND: After vidian neurectomy, low reported rates of dry eye syndrome (DES) seemed incompatible with the high success rate of nerve severance in previous studies. This study aimed at understanding of the pathophysiology of lacrimation and evaluating the effect of thermal injury through the distal stump on the sphenopalatine ganglion (SPG) after vidian neurectomy. METHODS: A randomized, double-blind, controlled study was performed to evaluate the DES. Eighty precise vidian neurectomies were randomized in a 1:1 ratio to groups 1 and 2. Group 1 represented the cauterization and was used in both distal and proximal nerve stumps, whereas only the proximal nerve stump was cauterized in group 2 subjects. The DES was evaluated with Schirmer's test and ocular surface disease index (OSDI) before and after surgery at 7-10 days and 30 days, respectively. RESULTS: In group 1, the Schirmer's test showed a mean decline of 20 mm (20/30, 66%) at 7-10 days and 15 mm (15/30, 50%) at 30 days. In group 2, the Schirmer's test revealed significantly lesser dry eye problems, with a mean decline of 16 mm (16/30; 52%) at 7-10 days and 2 mm (2/30; 6%) at 30 days. The significantly less postoperative dry eye problems in group 2 can be shown by the OSDI at 7-10 days, but not at 30 days. The mean follow-up period was 24 months. No recurrence of nasal allergy symptoms was noted in the follow up period. CONCLUSION: The significant advantage of preservation of the SPG function is justified by Schirmer's test, although the effect did not appear to be comparable with the clinical manifestations evaluated by OSDI at 30 days. Nevertheless, the preservation of distal stump from preventive cauterization can still offer better eye ball moisture in the early evaluation of DES.

Botulinum toxin type a injection for lateral canthal rhytids : effect on tear film stability and tear production.

IMPORTANCE: Botulinum toxin injection for lateral canthal rhytids has been reported to result in dry eye, but its effect on tear film stability and tear production has not been studied thoroughly. OBJECTIVE: To investigate the effect of botulinum toxin type A on tear film stability and tear production after treatment of lateral canthal rhytids. DESIGN, SETTING, AND PARTICIPANTS: We performed a clinical intervention study at a regional hospital in Taiwan of 58 women 30 to 60 years of age with lateral canthal rhytids from January 1 through December 31, 2011. INTERVENTIONS: Botulinum toxin type A at 2 different preparations and doses (dose A: 3 injections of 2 U in 0.05 mL of normal saline per injection; dose B: 3 injections of 4 U in 0.05 mL of normal saline per injection) was injected at the lateral canthal areas. One eye of each study participant was randomly chosen for dose A, and the other eye received dose B. MAIN OUTCOMES AND MEASURES: Baseline tear film break-up time (TBUT) and Schirmer tests without and with anesthesia were measured before and at 1 week, 1 month, 3 months, and 6 months after botulinum toxin injection. The TBUT and Schirmer test results were compared between different periods and doses. RESULTS: The TBUT decreased significantly at 1 week after botulinum toxin type A injection (P = .003), and the effect persisted at 1 month and 3 months after treatment (P = .01 and .02, respectively). In younger participants, the TBUT recovered faster than in older patients. The results of the Schirmer tests without and with anesthesia decreased gradually, with significant reduction at 1 month after treatment (P = .05 and .02, respectively) and then recovered gradually. Both the TBUT and Schirmer test results decreased more in eyes that received dose B than in those that received dose A; however, none of the differences were statistically significant. CONCLUSIONS AND RELEVANCE: Tear film stability decreased as early as 1 week after botulinum toxin type A treatment for lateral canthal rhytids, and the effect persisted for more than 3 months. Tear production decreased to the trough at 1 month after treatment and then recovered gradually.

Is being female a risk factor for shallow anterior chamber? The associations between anterior chamber depth and age, sex, and body height.

AIM OF STUDY: To analyze the association between anterior chamber depth (ACD) and age, sex, and body height (BH). MATERIALS AND METHODS: One thousand four hundred eighty eyes of 1480 adults 40 years of age and older receiving preoperative evaluation for cataract surgery were recruited consecutively from June 1, 2006, to December 31, 2010. ACD was measured with the Zeiss IOLMaster. Univariate and multivariate linear regression models were used to analyze the correlations, and receiving operator characteristic (ROC) curves and the area under the curve (AUC) were used for evaluating the predictability of an ACD less than 2.70 mm. RESULTS: ACD was negatively correlated with age and positively correlated with BH in both univariate and multivariate regression analysis (P < 0.001). Sex was associated with ACD in univariate analysis, but not after adjustment with age and BH. In predicting an ACD less than 2.70 mm, the AUCs of ROC curves for 'age and sex', 'age and BH', and 'age, sex, and BH' were 0.687, 0.689, and 0.689, respectively. CONCLUSION: Age and BH were independent associating factors of ACD; however, sex was not. Older people and shorter ones likely had shallower ACD, and therefore were predisposed to Primary angle closure glaucoma (PACG). The predictability of ACD by age and BH solely was low, and adding sex did not increase it.

The application of tissue engineering in reversing mitomycin C-induced ischemic conjunctiva.

The purpose of this study is to evaluate the angiogenic potential of collagen-glycosaminoglycan (CG) matrices in mitomycin C-induced ischemic conjunctival defect, in New Zealand white rabbits. After creating a conjunctival defect at the center of ischemic conjunctiva, a CG matrix was implanted into subconjunctival space to evaluate the conjunctival reepithelialization and angiogenesis during the wound healing process. In the grafted group, the vessel count of the healed conjunctiva was substantially elevated by two fold within the initial 4 weeks and the increased vascular content originated mostly from the fornix site. The rate of conjunctival reepithelialization was not retarded in the grafted group, and the final thickness of healed conjunctiva was similar in both grafted and ungrafted groups. The histological studies revealed that the collagen matrix did not elicit pronounced inflammatory reaction and the regenerated conjunctiva showed loosely arranged collagen deposition without significant scar formation. The α SMA staining positive myofibroblasts were identified in the acute inflammatory stage and were absent, 8 weeks after implantation in both groups. The results indicated that the porous collagen scaffold was able to enhance vascularization and physiological recovery of ischemic conjunctival defect, implying a potential alternative therapy for the ischemic leaking bleb after glaucoma filtrating surgery in ophthalmic practices.

Functional improvement and neurogenesis after collagen-GAG matrix implantation into surgical brain trauma.

Surgical or traumatic brain injury often leads to loss of cerebral parenchyma but there is as yet no clinically effective strategy for neural regeneration. Collagen glycosaminoglycan (collagen-GAG, CG) scaffolds have previously been used in many tissues in vivo but have never been utilized in the brain. Using an animal model, we investigated the effects of the implantation of CG scaffold matrix following surgical brain trauma. Results indicated that implantation of CG scaffold could significantly promote functional recovery following surgical brain trauma. The CG scaffold was found to facilitate proliferation, differentiation and migration of endogenous neural precursor cells (NPCs) both in the intra-matrix zone (IMZ) and lesion boundary zone (LBZ). The tissue concentration of brain-derived neurotrophic factor (BDNF) and glia-derived neurotrophic factor (GDNF) in the cortex demonstrated a sustained increase after implantation of CG scaffold following surgical brain trauma. These results suggest that the utilization of CG scaffolds can be considered as a potential clinical strategy for tissue regeneration and functional recovery after brain injury.

Transcleral posterior chamber paracentesis for angle closure glaucoma secondary to posterior chamber gas entrapment after intravitreal c3f8 injection in a phakic eye.

PURPOSE: The purpose of this study was to describe a new technique for treating a case of angle closure glaucoma secondary to posterior chamber (PC) gas entrapment after intravitreal C3F8 injection. METHODS: Retrospective case report. RESULTS: A 26-year-old woman received intravitreal injection of 0.4 mL of C3F8 after segmental scleral buckling for retinal detachment of her phakic eye. Prone positioning was not maintained postoperatively, and severe eye pain developed within hours of surgery. Intraocular pressure increased to 50 mmHg, and PC was found to be filled with gas accompanying with 360° iridocorneal apposition and angle closure. Transcleral PC paracentesis was performed to evacuate the gas. Anterior chamber angle was reopened inferiorly, and intraocular pressure dropped to 13 mmHg immediately and remained normal. No evidence of lens or iris damage was noted. Postoperatively, the vision improved to 20/25 without major sequelae. CONCLUSION: Posterior chamber gas entrapment with anterior chamber collapse is a rare complication of intravitreal gas injection in phakic eyes. Transcleral PC paracentesis is a safe way to treat angle closure glaucoma secondary to PC gas entrapment.