Pukhraj Rishi

Lysyl Oxidase Activity in the Ocular Tissues and the Role of LOX in Proliferative Diabetic Retinopathy and Rhegmatogenous Retinal Detachment

PURPOSE Lysyl oxidase (LOX) cross-links the side chain of collagen and elastin and thereby contributes to extracellular matrix (ECM) integrity. ECM remodeling is seen in various ocular diseases. Until now, there have been no reports on the LOX enzymes activity in ocular tissues. The purpose of this study was to estimate LOX activity and expression in human donor ocular tissues and to measure the specific activity of LOX in the vitreous of proliferative diabetic retinopathy (PDR) and rhegmatogenous retinal detachment (RRD). METHOD Human donor eyeballs obtained from an eye bank were used to study tissue distribution of LOX. Human vitreous specimens were obtained during vitreoretinal surgery from PDR (n = 16) and RRD (n = 10). LOX activity was estimated by N-acetyl-3,7-dihydroxyphenoxazine assay, immunohistochemistry, and real-time polymerase chain reaction (RT-PCR). Matrix metalloprotease (MMP)-2 and -9 were quantified in the vitreous by sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS The specific activity of LOX in ocular tissues was on the order of vitreous, iris ciliary body, lens, choroid RPE, and retina, which were comparable by mRNA expression and immunolocalization. The vitreous level of LOX activity decreased significantly in PDR and RRD, with an increase in total MMP-2 and -9 levels compared with normal donor vitreous. CONCLUSIONS LOX activity showed a statistically significant decrease in the vitreous of PDR and RRD relative to control specimens. This effect can contribute to the inadequate collagen cross-linking that causes the ECM changes that occur in these diseases.

Short-term results of intravitreal dexamethasone implant (OZURDEX(®)) in treatment of recalcitrant diabetic macular edema: A case series.

Context: Dexamethasone Posterior-Segment Drug Delivery System is a novel, biodegradable, sustained-release drug delivery system (OZURDEX®) for treatment of macular edema following retinal vein occlusion and posterior uveitis. However, its potential role in management of diabetic macular edema has not been reported yet. Aim: The aim was to evaluate the safety and efficacy of (OZURDEX®) in patients with recalcitrant diabetic macular edema (DME). Setting and Design: A retrospective, interventional case series from a tertiary eye care center in India is presented. Inclusion criteria comprised patients presenting with recalcitrant DME, 3 or more months after one or more treatments of macular laser photocoagulation and/or intravitreal anti-vascular endothelial growth factor (VEGF) injections. Exclusion criteria included history of corticosteroid-responsive intraocular pressure (IOP) rise, cataract extraction, or other intraocular surgery within 3 months. The main outcome measure was visual acuity at 1 and 4 months after OZURDEX® injection. Secondary outcome measures included change in central macular thickness on Optical coherence tomography (OCT) and changes in IOP following intravitreal OZURDEX® implant. Of 18 eyes (17 patients) with recalcitrant diabetic macular edema that underwent OZURDEX® implant, three eyes (two patients) had follow-up of more than 3 months post-injection. Results: Mean age of patients was 56 years. Mean duration of diabetes mellitus was 16.6 years. Systemic control of DM was good as assessed by FBS/PPBS and HbA1c. The pre-operative mean central macular thickness was 744.3 μm and improved to 144 and 570 μm at months 1 and 4, respectively. Preoperative mean BCVA was 0.6 logMAR units and improved to 0.3 and 0.46 logMAR units at month 1 and 4, respectively. The mean follow-up was 4.3 months (range 4-5 months). Conclusion: OZURDEX® appears efficacious in management of recalcitrant diabetic macular edema. The results of the ongoing POSURDEX® study will elaborate these effects better.

Endophthalmitis caused by Enterococcus faecalis: a case series.

Background: To profile the etiology, clinical features, visual and anatomical outcomes in eyes diagnosed with Enterococcus faecalis endophthalmitis. Methods: A single (tertiary care) center, Retrospective interventional case series. Clinical and microbiological records of 26 consecutive eyes with culture positive E. faecalis endophthalmitis treated at a tertiary referral ophthalmic hospital in south India from 1st January 1995 to September 2007 were reviewed and analyzed. Results: Of the twenty-six eyes, 12 were of postsurgical etiology, 11 cases were posttraumatic while 3 were of endogenous causes. Two eyes had an intraocular foreign body. Initial mean visual acuity was 3.19 logMAR (range: 0.77–4). All cases were treated with vitrectomy and intravitreal injections. Six cases developed retinal detachment after initial surgery, but only 30.7% eyes had a poor anatomical outcome (8 patients out of 26). All cases except one were sensitive to Vancomycin. Final mean visual acuity was 2.12 logMAR (range: 0.17–4). Paired ‘t’ test showed statistically significant (P = 0.008) good visual outcome (better than or equal to 3/60). Conclusions: Surgery (12 of 26 eyes) and trauma (11 of 26 eyes) were the commonest causes of E. faecalis endophthalmitis. Our results indicate that early surgical intervention can lead to a good functional outcome despite the virulent nature of the organism. Since almost all the cases were sensitive to Vancomycin, it may be considered as a first line drug in the management of such eyes.

Boston keratoprosthesis for keratopathy in eyes with retained silicone oil: a new indication.

Purpose: To analyze the visual outcome of Boston keratoprosthesis for keratopathy in silicone oil-filled eyes. Methods: Retrospective chart review of patients with silicone oil-induced keratopathy undergoing Boston keratoprosthesis between January 2008 and June 2010 was performed. Patients received Boston keratoprosthesis as the primary procedure or after a failed penetrating keratoplasty because of silicone oil-induced keratopathy after assessing possible visual potential. Silicone oil had to be retained in all eyes because of persistent ocular hypotony. Results: Of the 8 eyes that underwent surgery, anatomic retention and visual improvement were noted in 7 eyes (87.5%). The visual acuity improved to 20/200 or better in 6 eyes (66.67%). Repeated corneal melt necessitated the removal of the prosthesis with corneal transplant in 1 eye. Membranectomy was performed twice for retroprosthetic membrane in 1 eye. Conclusions: Boston keratoprosthesis seems to be a viable option for visual rehabilitation in postvitrectomized eyes with a decrease in vision due to retained silicone oil-induced keratopathy.

Acute Postoperative Bacillus cereus Endophthalmitis Mimicking Toxic Anterior Segment Syndrome

OBJECTIVE To study the clinicomicrobiologic characteristics and treatment outcomes in eyes with acute postoperative endophthalmitis (APE) owing to Bacillus cereus from a tertiary eye-care center. DESIGN Retrospective, interventional case series. PARTICIPANTS Case records of all eyes with culture-proven APE attributable to B cereus from January 2000 to May 2011 were identified from a computerized database and evaluated. METHODS Clinical features at time of presentation, microbiological characteristics, and treatment measures were recorded. A thorough literature search using PubMed and the Cochrane Library databases was done to identify all cases of APE owing to Bacillus species reported to date and clinical characteristics of these eyes was compared with our series. MAIN OUTCOME MEASURES Structural (globe salvage) and functional (visual rehabilitation) outcomes at last follow-up visit. RESULTS We found 6 sporadic cases that experienced APE during the study period. All eyes had a fulminant onset within the first 24 hours of cataract surgery with extremely high intraocular pressure (IOP) and corneal edema similar to toxic anterior segment syndrome (TASS). However, these eyes progressed rapidly to develop corneal infiltrates, scleral and uveal tissue necrosis with hyphema, brownish exudates in anterior chamber and necrotizing retinitis within hours despite immediate initiation of intravitreal pharmacotherapy and vitrectomy. All eyes demonstrated gram-positive bacilli from the aqueous and B cereus was isolated, which was sensitive to conventional antibiotics except penicillin. Two eyes required therapeutic keratoplasty, combined with a scleral patch graft in 1 eye, 1 eye was eviscerated after 48 hours of onset of symptoms, and 2 eyes experienced phthisical changes within 10 days of onset. CONCLUSIONS We found that APE owing to B cereus has an onset within 12 to 24 hours of intraocular surgery and simulates TASS in the first few hours. The clinical course is marked by rapidly worsening necrotizing infection, leading to very poor outcomes despite early institution of appropriate therapy. One must closely observe every case of TASS that presents with intense pain and extremely high IOP and rule out APE owing to B cereus with microbiologic testing. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Intravitreal bevacizumab for choroidal neovascular membrane associated with Best's vitelliform dystrophy.

Bests vitelliform macular dystrophy is a hereditary form of progressive macular dystrophy that can be complicated by choroidal neovascularization. Authors report successful treatment of choroidal neovascularization with intravitreal bevacizumab in one such eye in an ‘adult’ Indian male with visual improvement. A 23-year-old male presented with diminution of vision in the right eye for the past sixteen months. Visual acuity was 20/400 in the that eye. After three consecutive intravitreal injections of bevacizumab (1.25 mg/0.05 ml), vision improved to 20/120. Seven months following the last injection of bevacizumab, fundus appeared stable and visual acuity was maintained. No drug-related ocular or systemic side effects were encountered. To the best of our knowledge (PubMed search), this is the first report of its kind in an adult Indian patient. Intravitreal bevacizumab appears to be a promising and cost-effective modality of treatment in such eyes with potential for improvement in vision. However, a long-term follow-up is warranted.

Clinical and histopathological features of posttraumatic iris cyst

Iris cyst excision involves complex surgical maneuvers and may have a variable visual outcome depending upon preexisting and postoperative complications. Hereby, we report a case series of 10 eyes from which posttraumatic iris cysts were excised and proven histopathologically. Histopathology records were reviewed. Data regarding patient profile, clinical profile, surgical details, treatment outcomes and follow-up were reviewed. Outcome measures were defined as recurrences, visual acuity and number of other surgeries required. Non-parametric Wilcoxon test was used to compare changes in the visual acuity and Fisher test was used to find out the significance of several risk factors. Mean age was 24.7 years (3-58 years). Mean follow- up was 2.36 years. Mean preoperative logMAR visual acuity was 0.56 in comparison to final logMAR visual acuity of 1.62. Factors related to adverse functional outcome were related to post-surgical complications.

Hemi-central retinal artery occlusion in young adults

Amongst the clinical presentations of retinal artery occlusion, hemi-central retinal artery occlusion (Hemi-CRAO) is rarely described. This case series of four adults aged between 22 and 36 years attempts to describe the clinical profile, etiology and management of Hemi-CRAO. Case 1 had an artificial mitral valve implant. Polycythemia and malignant hypertension were noted in Case 2. The third patient had Leiden mutation while the fourth patient had Eisenmenger’s syndrome. Clinical examination and fundus fluorescein angiography revealed a bifurcated central retinal artery at emergence from the optic nerve head, in all cases. Color Doppler examination of the central retinal artery confirmed branching of the artery behind the lamina cribrosa. It is hypothesized that bifurcation of central retinal artery behind the lamina cribrosa may predispose these hemi-trunks to develop an acute occlusion if associated with underlying risk factors. The prognosis depends upon arterial recanalisation and etiology of the thromboembolic event.

Using risk factors for detection and prognostication of uveal melanoma

The early detection of malignancy, particularly uveal melanoma, is crucial in protecting visual acuity, salvaging the eye, and preventing metastasis. Risk factors for early detection of uveal melanoma have been clearly delineated in the literature and allow identification of melanoma when it is tiny and simulates a nevus. These factors include thickness >2 mm, presence of subretinal fluid (SRF), symptoms, the orange pigment, margin near optic disc, acoustic hollowness, surrounding halo, and absence of drusen. The importance of early detection is realized when one considers melanoma thickness, as each millimeter increase in melanoma thickness imparts 5% increased risk for metastatic disease. Newer imaging modalities like enhanced depth imaging optical coherence tomography and fundus autoflouroscence facilitate in detection of SRF and orange pigment. Additional molecular biomarkers and cytological features have been identified which can predict the clinical behavior of a small melanocytic lesion. Features that suggest a poor prognosis include higher blood levels of tyrosinase m-RNA, vascular endothelial growth factor, insulin-like growth factor; monosomy 3 and gains in chromosome 8. Management of uveal melanoma includes enucleation (for large), local eye wall resection, brachytherapy, charged particle irradiation, and thermotherapy (for small to medium tumors). Although the role of a good clinical evaluation cannot be underestimated, it is advisable to evaluate the various radiological, molecular, and cytological features, to enhance the accuracy of early diagnosis and improved prognosis.

Delayed onset chloroquine retinopathy presenting 10 years after long-term usage of chloroquine

Chloroquine retinopathy is a known complication of long-term use of chloroquine. This retinopathy can appear even after usage of chloroquine has stopped. The present case report describes the history and clinical features of chloroquine retinopathy developing a decade after discontinuing the drug.