Richard John Haynes

Antimicrobial defensin peptides of the human ocular surface.

BACKGROUND/AIMS The antimicrobial activity of the tear film exceeds the activity of its known constituents. The authors postulate that this excess activity is the result of antimicrobial peptides called defensins, and they aimed to look for defensins in the human eye. METHODS Evidence of defensin production was sought by reverse transcriptase polymerase chain reaction (RT-PCR). Intron spanning primers were designed for β defensins 1 and 2, and α defensins 5 and 6. RT-PCR was performed on cornea, conjunctiva, and lacrimal gland samples, and reaction products were size fractionated and sequenced to confirm their identity. A monoclonal antibody was utilised for the detection of α defensins 1, 2, and 3 in tissue sections and in immunoblots of tears. RESULTS RT-PCR revealed β defensin 1 message in samples of conjunctiva, cornea, and lacrimal gland. β Defensin 2 message was detected in the conjunctiva and cornea but was absent from the lacrimal gland. α Defensin 5 and 6 message was absent in these tissues but α defensins 1, 2, and 3 were detected in normal tears, lacrimal gland, and inflamed conjunctiva by immunochemistry. CONCLUSION The data suggest the human eye innately produces a spectrum of antimicrobial defensin peptides. Defensins hold therapeutic potential in ocular infections as they have a broad spectrum of antimicrobial activity (bacteria fungi and viruses ) and accelerate epithelial healing.

E-cadherin distribution and epithelial basement membrane characteristics of the normal human conjunctiva and cornea

The conjunctival mucosa has several similarities to the mucosal immune system of the gut and bronchus. Like the gut and bronchial mucosa, the conjunctiva is capable of inducing tolerance to encountered antigens and possesses a repertoire of CD8+ intraepithelial lymphocytes (IELs) bearing the human mucosal lymphocyte-1 antigen (HML-1) which has been shown to be an αEβ7 integrin. The epithelial cells surface ligand for HML-1 is E-cadherin. The distribution of E-cadherin in the normal human conjunctiva and cornea is not known. We investigated E-cadherin distribution in the conjunctiva and cornea by immunohistochemistry. E-cadherin was found to be present in all layers of the conjunctival epithelium but not in corneal epithelium. In the conjunctiva it may act as a ligand for the HML-1+ IELs. The specific location of IELs along the basal cells of the conjunctiva compared with the generalised distribution of E-cadherin through all layers, indicates that factors other than E-cadherin binding determine the distribution of HML-1+ IELs. We performed electron microscopy on de-epithelialised conjunctival and corneal samples. We demonstrated the presence of epithelial basement membrane pores in the conjunctiva but not in the cornea. Lymphocyte migration from the substantia propria to the intraepithelial compartment appears to occur through these pores, which may also serve as a conduit for antigen presentation by epithelial antigen presenting cells (APCs) to lymphocytes in the substantia propria.

β‐Defensin 1 haplotype associated with postoperative endophthalmitis

Acta Ophthalmol. 2010: 88: 786–790

A novel technique to treat traumatic corneal perforation in a case of presumed brittle cornea syndrome

The management of corneal perforation can be difficult. We describe a novel technique to manage corneal perforation in brittle cornea syndrome (BCS). A 14-year-old daughter of consanguineous Pakistani parents presented with a history of a bottle cap having struck her left eye. She had a history of multiple trauma to both eyes since childhood. At presentation, there was limbus-to-limbus corneal perforation in the left eye. The right eye had a failed corneal graft (for extensive corneal opacities). An examination under general anaesthesia showed a collapsed left eye with rolled-in corneal edges, without any scleral injury. There was partial aniridia, aphakia and prolapsed vitreous, with no obvious retinal detachment. She was also noted to have hypermobility of …

E-Cadherin distribution in normal and dysplastic conjunctival epithelium.

Eye possible endogenous sources. He was a farmer by profession, but there was no history of injury with vegetative matter. Although we found an endogenous embolus in the iris vasculature, we were not able to locate the primary source. Our case highlights the need to consider fungal etiology as a differential diagnosis in an iris granuloma. In our case excision biopsy of the iris granuloma and an AC tap played a vital role in clinching the diagnosis. Institution of steroids without antifungal treatment could be disastrous in case of a misdiagnosis. Our case is the first report of Aspergillus iris granuloma in an immunocompetent individual. A high degree of clinical suspicion, combined with microbiological and histopathological evaluation helped to arrive at an appropriate diagnosis and successful management.

A case of bilateral endophthalmitis and carriage of β-defensin 1 –44CC genotype

β-defensins are innate antimicrobial peptides found in a variety of ocular tissues and are critical to the immune response.1–3 We present a case of bilateral endophthalmitis and show the carriage of the –44CC genotype in β-defensin 1. The polymorphism has previously been linked to increased susceptibility to infection.4–7 View this table: Table 1 Sequence variations seen in β-defensin 1 and β-defensin 2 genes in a patient with bilateral endophthalmitis An 80-year-old man underwent cataract surgery in the right eye complicated by a capsular tear. Within 4 days he returned with a hypopyon, painful loss of vision and reddening of the right eye. Endophthalmitis was diagnosed, an urgent vitreous tap was performed and intravitreal cetazidime and vancomycin were started. Microscopical examination revealed Gram-positive cocci, but no final growth of organisms. The right eye responded to treatment, but 1 month later a retinal detachment was diagnosed in the same eye. This was surgically repaired without complications. A year later, after an uncomplicated left cataract surgery in another hospital, the patient presented again with endophthalmitis symptoms, including hypopyon, rapid visual loss (hand movements), pain and reddening of the …

Risk factors for retinal detachment following cataract surgery: the impact of posterior capsular rupture.

Aim To investigate risk factors for retinal detachment (RD) after cataract surgery, particularly posterior capsular rupture (PCR) with or without vitreous loss. Methods Single centre electronic medical record database study of 18 065 consecutive first eye cataract operations performed between 2005 and 2014. Survival analysis was performed with Kaplan–Meier curves and a Cox proportional hazard regression analysis to calculate HRs with respect to RD. Results The RD rate at 3 months and 7 years was 0.067% and 0.30%, respectively, with a median time to RD of 15 months (mean: 18 months, range: 0–84 months). Men had a higher RD risk (HR 2.00; 95% CI 1.03 to 3.88; p=0.03) in the univariate model. Patients <60 years and those >80 years had an HR of 5.12 (95% CI 2.60 to 10.07; p<0.001) and 0.16 (95% CI 0.38 to 0.69; p=0.01), respectively, compared with patients 60–80 years of age. Eyes longer than 25 mm had an HR of 3.98 (95% CI 1.93 to 8.20; p<0.001) compared with eyes 23–25 mm. PCR occurred in 400 (2.2%) eyes. The HR for RD was 12.83 (95% CI 5.62 to 29.30; p<0.001) for PCR with vitreous loss. There were no RD events in eyes with PCR without vitreous loss. Conclusions The risk for RD after cataract surgery is higher in younger patients and eyes with longer axial length or PCR with vitreous loss during surgery.

Delayed choroidal hemorrhage with concomitant subconjunctival hemorrhage after retinal detachment surgery.

BACKGROUND Suprachoroidal hemorrhage is a known serious complication of all types of intraocular surgery and is associated with severe visual debility. Most cases of suprachoroidal hemorrhage occur intraoperatively. Suprachoroidal hemorrhage as a complication of vitrectomy has been described near the end of vitrectomy or on the first postoperative day. METHODS This case report describes a patient presenting with a delayed suprachoroidal hemorrhage occurring 5 days after vitreoretinal surgery in association with subconjunctival hemorrhage. RESULTS AND CONCLUSION To our knowledge, we report the first case of a delayed suprachoroidal hemorrhage associated with vitreoretinal surgery. With proper management, the outcome is not always unfavorable.