Role of vascular endothelial growth factor in the breakdown of the blood-aqueous barrier after retinal laser photocoagulation in pigmented rabbits

Effects of intravitreal conbercept before panretinal photocoagulation on lipid exudates in diabetic macular documented by optical coherence tomography

AIM

To evaluate the effects of intravitreal conbercept (IVC) as adjunctive treatments before panretinal photocoagulation (PRP) to decrease hyperreflective dots (HRDs) in Chinese proliferative diabetic retinopathy (PDR) patients.

METHODS

Fifty-nine enrolled patients were categorized into 2 groups: single dose IVC (0.5 mg/0.05 mL) 1wk before PRP (Plus group) or PRP only (PRP group). Six months later, we measured the best corrected visual acuity (BCVA), central macula thickness (CMT) by optical coherence tomography and counted the number of HRDs in different retina layers.

RESULTS

The average CMT significantly decreased in Plus group but increased in PRP group. The average BCVA in the Plus group was also significantly better than that in the PRP group. Total HRDs decreased in the Plus group but increased in PRP group significantly. IVC pre-treatment has beneficial effects on reducing HRDs forming in the inner retina layer while the PRP alone increased the HRDs in the outer retina layer.

CONCLUSION

IVC is a promising adjunctive treatment to PRP in the treatment of PDR. Single dose IVC one week before PRP is suggested to improve retina blood-retina barrier, decrease lipid exudate and inhibit HRDs development in PDR.

Primary Angle Closure Glaucoma-associated Genetic Polymorphisms in Northeast Iran

Purpose

To evaluate the association of five different polymorphisms from a genome-wide-associated study with susceptibility to glaucoma in the northeast Iranian population.

Methods

Hundred and thirty patients with primary angle closure glaucoma (PACG) and 130 healthy controls were genotyped for the polymorphic regions with the aid of tetra-amplification refractory mutation system-polymerase chain reaction. The association of these variants with the disease susceptibility was measured statistically with the logistic regression method.

Results

Hundred and thirty patients with PACG (53 males, 77 females) with a mean age of 64.5 ± 6.2 years and 130 healthy control subjects (51 males, 79 females) with a mean age of 64.0 ± 5.7 years were selected for evaluation. There was a significant association between rs3816415 (P = 0.005), rs736893 (P< 0.001), rs7494379 (P< 0.001), and rs1258267 (P = 0.02) with PACG susceptibility. This association could not be shown for rs3739821.

Conclusion

It was revealed that studied variants in GLIS3, EPDR1, FERMT2, and CHAT genes can contribute to the incidence of PACG. Additional studies in other populations are needed to evaluate DPM2-FAM102A.

Common polymorphisms of the hOGG1, APE1 and XRCC1 genes correlate with the susceptibility and clinicopathological features of primary angle-closure glaucoma

The present case study aims to elucidate the correlation between the human 8-hydroxyguanineglycosylase (hOGG1), APE1 and X-ray repair cross-complementing gene 1 (XRCC1) gene polymorphisms to the susceptibility and clinicopathological features of primary angle closure glaucoma (PACG) in a Chinese Han population. Blood samples were obtained from 258 PACG patients (case group) and 272 healthy volunteers (control group). PCR with sequence-specific primer (PCR-SSP) was used to determine the allele frequencies and genotype distributions of the hOGG1, APE1 and XRCC1 genes. The risk factors of PACG were determined using logistic regression analysis. The results indicated that hOGG1 Ser326Cys, APE1 Asp148Glu and XRCC1 Arg399Gln polymorphisms were correlated with the risk of PACG. Furthermore, there were thicker corneas, higher intraocular pressure (IOP) and a shorter axial length in patients carrying the mutant genotypes of hOGG1 Ser326Cys (Ser/Cys + Cys/Cys), APE1 Asp148Glu (Asp/Glu + Glu/Glu) and XRCC1 Arg399Gln (Arg/Gln + Glu/Glu) than those carrying the corresponding wild-type genotypes. According to the logistic regression analysis, Asp148Glu and Arg399Gln polymorphisms, a short axial length and high IOP are major risk factors for PACG. These findings reveal that hOGG1 Ser326Cys, APE1 Asp148Glu and XRCC1 Arg399Gln polymorphisms are correlated with the risk and clinicopathological features of PACG in a Chinese Han population.

Laser flare-cell photometer: principle and significance in clinical and basic ophthalmology

A slit-lamp examination is an indispensable and essential clinical evaluation method in ophthalmology, but, it is qualitative subjective. To complement its weaknesses in making a quantitative evaluation of flare intensity and number of cells in the aqueous humor in the eye, we invented the laser flare-cell photometer in 1988. The instrument enables a non-invasive quantitative evaluation of flare intensity and number of cells in the aqueous with good accuracy and repeatability as well as maneuverability equal to slit-lamp microscopy. The instrument can elucidate the pathophysiology in the blood-aqueous barrier (BAB) function in a variety of ocular disorders. The accuracy of the instrument makes it possible to investigate not only the pathophysiology of intraocular disorders but also the effects of various drugs and surgical procedures in BAB. The instrument does not only lighten the burden on patients in clinical examinations and study but it also helps minimize the sacrifice of experimental animals and improves the reliability of the results by minimizing inter-individual variations through its good repeatability. Here I shall relate how the instrument has been applied to clinical and basic studies in ophthalmology and what novel knowledge its application contributed to pathophysiology in ophthalmology.

The effect of triamcinolone acetonide or bevacizumab on the levels of proinflammatory cytokines after retinal laser photocoagulation in pigmented rabbits

Although laser photocoagulation is a gold standard for the treatment of retinal ischemic diseases, thermal burn induces the inflammation and the progression of macular edema. To prevent this complication, combination therapy using anti-vascular endothelial growth factor (VEGF) drugs or steroids is clinically utilized, however the mechanisms are still unclear. In this study, we aimed to evaluate the changes in inflammatory and angiogenic cytokine levels in aqueous humor and vitreous body after intravitreal injection of bevacizumab (IVB) or triamcinolone (IVTA), as well as sub-Tenon injection of triamcinolone (STTA) after retinal laser photocoagulation in rabbits. Pigmented rabbits were treated with retinal laser photocoagulation and divided into 4 groups, namely Control (no additional treatment), IVB, IVTA or STTA accordingly. Samples of vitreous and aqueous humor were collected on post-treatment days 0, 1, 7 and 14. The levels of intraocular VEGF, interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1) and monocyte chemotactic protein-1 (MCP-1) were measured using an immunoassay. The levels of VEGF, IL-6, ICAM-1 and MCP-1 were significantly elevated 1 day after laser treatment. IVTA and STTA significantly reduced the increase in the levels of VEGF, IL-6, ICAM-1 and MCP-1, while IVB reduced that of VEGF only in aqueous humor and vitreous body. The protein amount in the aqueous humor transiently increased 1 day after laser, and was significantly prevented by IVTA or STTA but not IVB. Data showed that bevacizumab only reduced intraocular VEGF after laser, while triamcinolone suppressed both the expression of VEGF and proinflammatory cytokines. We propose that these cytokine profiles may play an important role in the pathogenesis of inflammation after photocoagulation and the underlying mechanism of treatment with anti-VEGF drug and steroids.

Transvitreal fibrinoid pseudoendophthalmitis after diabetic vitrectomy

OBJECTIVE

To describe the presentation and clinical course of noninfectious transvitreal fibrinoid response after vitrectomy for diabetic retinopathy.

METHODS

Data collected from charts included age, gender, surgical indication, preoperative and serial visual acuities, vitrectomy procedures, and postoperative clinical characteristics of involved eye.

RESULTS

Patients had a mean age of 65.6 years (51-82 years) with 5 women and 2 men. Patients had a range of diabetes duration from 4 to 27 years and a mean HgbA1C of 9.1 (5.8-14.1). Surgical indications included nonclearing vitreous hemorrhage (five), tractional retinal detachment (three), and clinically significant macular edema (one). All patients manifested transvitreal bands on postoperative Day 1 without anterior chamber reaction. Mean time to resolution of transvitreal bands was 8.75 days (4-15 days) on standard postoperative topical medications alone.

CONCLUSION

Transvitreal fibrinoid response after diabetic vitrectomy is a remarkable phenomenon that can occur in a wide variety of patients with diabetic retinopathy. It is important to differentiate this from infectious endophthalmitis, as this series of cases resolved spontaneously on topical medications alone.