Epidemiology and recurrence rate of pterygium post excision in Ghanaians.

OBJECTIVES: To determine the epidemiology and recurrence rate of pterygium after excision using bare sclera technique. DESIGN: Prospective non-comparative study. SETTING: Ophthalmology unit, Korle-Bu Teaching Hospital, Accra, Ghana. METHODS: The study involved 60 consecutive patients with primary apterygial from July 1998 to December 2000 who had bare sclera excision after informed consent. They were post-operatively followed up for 30-months. RESULTS: Thirty-five patients (58%) were females. The patients' ages ranged from 17-75 years, mean (±12.6). Overall recurrence was 22(37%). The main complications encountered include were granuloma 20 %(n=12), restriction in medial rectus muscle motility 2(3%), persistent vascularisation at excision site 2(3%) and adherence leucoma with uveitis 1(2%). No significant association was found between recurrence and pterygium morphology, calcification, allergy and occupation (indoor or outdoor). CONCLUSION: The recurrence rate after pterygium excision using bare sclera technique in Ghanaians is high (37%).

Ocular surface changes in limbal stem cell deficiency caused by chemical injury: a histologic study of excised pannus from recipients of cultured corneal epithelium.

PURPOSE: To report histopathologic changes of the ocular surface pannus in patients with severe limbal stem cell deficiency (LSCD). METHODS: Corneal and conjunctival pannus tissues from 29 patients undergoing ocular reconstruction with cultured limbal cell transplantation were included. The medical records of these patients were reviewed for demographics, aetiologic diagnosis, type of injury, interval between the initial insult and excision of pannus, and medical history involving human amniotic membrane (HAM) or limbal transplantation. The paraffin-embedded tissues were reviewed for epithelial changes, type-degree of fibrosis, degenerative changes, vascular changes, conjunctivalization of corneal surface, and evidence of residual HAM. We attempted a clinicopathologic correlation to understand the pathogenesis of pannus formation in LSCD. RESULTS: The 29 tissues were from 29 eyes of patients with primary aetiology of chemical burn in 89.6% (undetermined in 10.4%) of cases. The pannus showed epithelial hyperplasia in 62%, active fibrosis in 66%, severe inflammation in 21%, giant cell reaction in 28%, and stromal calcification in 14% cases. Goblet cells were seen over the cornea in 64% cases; their absence was associated with squamous metaplasia of the conjunctiva and with long duration of insult. Evidence of residual HAM was noted in 42% cases. CONCLUSIONS: The commonest cause of severe LSCD is alkali-induced injury. Goblet cells over the cornea were seen in 60% of cases. HAM used for ocular surface reconstruction could persist for long periods within the corneal pannus, thus raising the need for further studies with long-term follow-up.

Changing trends in ocular cysticercosis over two decades: an analysis of 118 surgically excised cysts.

PURPOSE: To evaluate the frequency of ocular cysticercosis and to demonstrate the changing trends in localisation of ocular cysticercosis along with a brief review of literature. METHODS: A retrospective analysis of histology proven ocular cysticercosis cases seen over a period of 20 years (1981 through 2000) was done. The pathology record forms were reviewed for demographics, clinical features with specific reference to the location of cysts in four subgroups: subconjunctival; intraocular orbit and eyelid. The distribution of cases in four five-year periods namely group A: 1981-1985, group B: 1986-1990, group C: 1991-1995 and group D: 1996-2000 and the changing trends in the location of cysts was evaluated. RESULTS: One hundred eighteen cysts from 118 patients aged 4-72 (mean 17.1) years were submitted to the pathology service of S D Eye Hospital, Hyderabad. Male to female ratio was 1: 1.2. Total number of cases in groups A, B, C and D were 33, 41, 16 and 25 respectively. Location of cysts was subconjunctival - 74 (62.7%); intraocular-31 (26.3%); orbital-8 (7%) and lid-5 (4%). In last 20 years, significant decrease (P =0.0001) was noted in subconjunctival cases (85% vs. 28%) with a significant rise (P =0.0001) in intraocular cysticercosis (6% vs. 60%). CONCLUSIONS: Frequency of surgically excised ocular cysticercosis remained constant over last two decades with an increasing manifestation of intravitreal cysticercosis in the recent years. This could imply either improved diagnostic modalities, available expertise in vitreo-retinal surgery or ineffective medical treatment for intraocular parasitic infection. The relative decrease in extraocular cysticercosis is probably due to the increased preference and success with medical management.

Technique of cultivating limbal derived corneal epithelium on human amniotic membrane for clinical transplantation.

BACKGROUND: The technique of transplantation of cultivated limbal epithelium rather than direct limbal tissue isa novel method of "cell therapy" involved in reconstructing the ocular surface in severe limbal stem cell deficiency [LSCD], caused by chemical burns. AIM: To describe a simple feeder-cell free technique of cultivating limbal epithelium on human amniotic membrane[HAM]. MATERIALS AND METHODS: The limbal tissues (2 mm) were harvested from patients with LSCD. These tissues were proliferated in vitro on HAM supplemented by human corneal epithelial cell medium and autologous serum. Cultures covering more > or = 50% area of 2.5 x 5 cm HAM were considered adequate for clinical use. The cultured epithelium was characterized by histopathology and immunophenotyping. RESULTS: A total of 542 cultures out of 250 limbal tissues were cultivated in the laboratory from January 2001 through July 2005. The culture explants showed that clusters of cells emerging from the edge of the explants in one-three days formed a complete monolayer within 10-14 days. In 86% of cultures (464 of 542), the growth was observed within one-two days. Successful explant cultures were observed in 98.5% (534 of 542 cultures) with 91% explant cultures showing an area of > or = 6.25 cm2 (6.25 - 12.5 cm2 range). The cultivated epithelium was terminated between 10-14 days for clinical transplantation. The problems encountered were inadequate growth (2 of 542) and contamination (2 of 542). CONCLUSIONS: We demonstrate a simple technique of generating a sheet of corneal epithelium from a limbal biopsy. This new technique could pave the way for a novel form of cell therapy.

Primary orbital aspergilloma of the exenterated orbit in an immunocompromized patient.

Aspergilloma is a fungal ball that usually forms in a preformed stationary cavity, mostly in lung and paranasal sinuses. We report a rare case of primary orbital Aspergilloma following exenteration for an invasive ocular surface squamous neoplasia, clinically mimicking a recurrence of the tumor. The fungal ball showed the presence of conidiophores with a globular head and a complete row of uni and biserrate phialides, suggestive of Aspergillus flavus species. The exposure to air in the orbit, possibly promoted the formation of conidiophores, which are normally seen when the organism is located in air cavities.

A comparative study of epiretinal membranes associated with Eales' disease: a clinicopathologic evaluation.

AIM: To study the histopathologic features and clinical correlation of epiretinal membranes (ERM) obtained from patients of Eales' disease and compare with other vasoproliferative disorders. METHODS: Retrospective analysis of epiretinal membranes submitted for histological evaluation between January 1995 and June 2001, from the patients of diabetic retinopathy and vascular occlusions (Group 1; vaso-occlusive disorders) and of Eales' disease (Group 2; vasoinflammatory disorders). Demographics, pre and postoperative visual acuity, and anatomic and histologic characteristics of membranes were studied. Histopathologic features and clinical outcomes were correlated between the groups. The results were analysed statistically by Student's t-test, Fisher's exact test and Kruskal-Wallis test. RESULTS: This study consisted of 42 patients, 24 in Group 1 and 18 in Group 2. Patients in Group 2 (33.0+/-9.2 years) were significantly younger than the patients in Group 1 (49.9+/-7.6 years) (P< or =0.0001). Final visual acuity of >20/400 was attained in 79.2% (19/24) patients in Group 1 and 83.3% (15/18) in Group 2 (P=1.0). Inflammatory membranes were significantly associated with presumed Eales' disease (94.4 vs 0%) (P< or =0.0001) and fibrovascular membranes with Group 1 (70.8% vs 33.3%) (P=0.028). Mast cells and eosinophils were observed as special features in epiretinal membranes of patients with Eales' disease. CONCLUSIONS: Histological features of ERM in Eales' disease are comparable to other vasoproliferative disorders except for features of inflammation. Presence of mast cells and eosinophils in epiretinal membranes of Eales' disease needs further investigation.

Granulomatous inflammation in Acanthamoeba keratitis: an immunohistochemical study of five cases and review of literature.

PURPOSE: Acanthamoeba keratitis usually presents as a necrotizing stromal inflammation. We report a rare presentation of granulomatous inflammation in Acanthamoeba keratitis METHODS: Retrospective clinico-pathologic case series. RESULTS: Five corneal tissues (3 corneal buttons, 2-eviscerated contents) from patients suffering from severe Acanthamoeba keratitis not responding to anti-Acanthamoeba treatment, revealed a florid granulomotous inflammation with multinucleated giant cells in the posterior stroma and around Descemet's membrane. Phagocytosed parasites were noted within the giant cells. Vascularization of the corneal stroma was noted in two cases. Immunophenotyping revealed a predominance of T lymphocytes and macrophages. Clinically, four of five cases had shown features of limbal and scleral involvement. CONCLUSION: Granulomatous inflammation in the posterior corneal stroma, is not an uncommon finding in Acanthamoeba keratitis and could possibly be immune-mediated, contributing to persistence and progression of disease. CLINICAL RELEVANCE: Presence of granulomatous inflammation in Acanthamoeba keratitis, in most cases is associated with limbal and scleral involvement and therefore could be considered as one of the poor prognostic markers. Further studies are required to ascertain the specific clinical features and appropriate management strategies in these cases.

Microsporidia: emerging ocular pathogens.

Microsporidia are eukaryotic, spore forming obligate intracellular parasites, first recognized over 100 years ago. Microsporidia are becoming increasingly recognized as infectious pathogens causing intestinal, ocular, sinus, pulmonary, muscular and renal diseases, in both immunocompetent and immunosuppressed patients. Ocular microsporidiosis, though uncommon, could be isolated or part of systemic infections. It occurs mainly in two forms: keratoconjunctivitis form, mostly seen in immunocompromised individuals; stromal keratitis form seen in immunocompetent individuals. Recent reports indicate increasing number of cases of ocular microsporidiosis in immunocompetent individuals. The ocular cases present as superficial keratitis in AIDS patients, and these differ in presentation and clinical course from the cases seen in immunocompetent individuals which mainly appear to be as deep stromal keratitis. For most patients with infectious diseases, microbiological isolation and identification techniques offer the most rapid and specific determination of the etiologic agent, however this does not hold true for microsporidia, which are obligate intracellular parasites requiring cell culture systems for growth. Therefore, the diagnosis of microsporidiosis currently depends on morphological demonstration of the organisms themselves, either in scrapings or tissues. Although the diagnosis of microsporidiosis and identification of microsporidia by light microscopy have greatly improved during the last few years, species differentiation by these techniques is usually impossible and electron microscopy may be necessary. Immuno fluorescent-staining techniques have been developed for species differentiation of microsporidia, but the antibodies used in these procedures are available only at research laboratories at present. During the last 10 years, molecular techniques have been developed for the detection and species differentiation of microsporidia.

Anterior stromal puncture in bullous keratopathy: a clinicopathologic study.

PURPOSE: We report our experience of anterior stromal puncture (ASP) in symptomatic chronic corneal edema patients awaiting penetrating keratoplasty (PK) and hypothesize the mechanism of action of ASP in bullous keratopathy (BK). METHODS: We reviewed the medical records of 28 patients with BK who underwent ASP between November 1996 and September 1999 with at least 1 month of follow-up. In all these patients, approximately 200 punctures were given with a bent 26-gauge needle sparing the peripheral cornea. Patients were examined on days 1 and 7, 1 month, and every 3 months after the procedure. The symptoms, corneal findings, and visual acuity of the patients at last follow-up were noted and compared with the preprocedure findings. For 11 patients who underwent PK, histopathologic study of corneal buttons was performed and a clinicopathologic correlation was attempted. RESULTS: Of the 28 patients, there were 15 men and 13 women with a mean age of 61.1 years. The clinical diagnosis was pseudophakic BK in 11 (39.3%), aphakic BK in 11 (39.3%), Fuchs' dystrophy in 4 (14.3%), failed graft in 1 (3.6%), and chronic corneal edema of unknown etiology in 1 (3.6%). The follow-up ranged from 1 to 33 months with a mean of 9.5 +/- 7.5 months. Symptomatic relief was noted in all. Twenty patients (71.4%) had complete relief, whereas eight patients (28.6%) experienced mild symptoms such as tearing and occasional pain. Visual acuity improved in 7 patients (25%), decreased in 12 (42.8%), and remained the same in 9 (32.4%). Objective evidence of scarring after ASP was noted in all patients. Complete regression of epithelial bullae and epithelial edema was found in 10 (35.7%) and partial regression in 18 (62.25%) patients. There was no progression or appearance of new blood vessels except in one patient (3.6%). Histologically, puncture marks and superficial stromal scarring were noted in all corneal buttons. Adhesion of epithelium with varying degrees of subepithelial fibrosis was seen in six, whereas in the remaining five buttons, there was complete denudation of the epithelium. Vascularization was seen in five and inflammation in two buttons. Clinicopathologic correlation revealed that symptomatic patients had persistent edema and loose adhesion of the epithelium to the stroma, resulting in detachment. CONCLUSIONS: ASP is a simple, safe, and cost-effective outpatient procedure for symptomatic relief in patients with BK. The possibility of decreased visual acuity after the procedure should be explained to all patients. Although ASP promoted subepithelial fibrosis in all cases, its subsequent adhesion is variable and probably has clinical relevance. Further studies could be directed toward identifying specific mediators that promote epithelial-stromal interaction and firm anchoring of epithelium to the underlying stroma.

Atypical Herpes simplex keratitis (HSK) presenting as a perforated corneal ulcer with a large infiltrate in a contact lens wearer: multinucleated giant cells in the Giemsa smear offered a clue to the diagnosis.

PURPOSE: To report a case of atypical herpes simplex keratitis initially diagnosed as bacterial keratitis, in a contact lens wearer. RESULTS: Case report of an 18-year-old woman using contact lenses who presented with pain, redness and gradual decrease in vision in the right eye. Examination revealed a paracentral large stromal infiltrate with a central 2-mm perforation. Corneal and conjunctival scrapings were collected for microbiological investigations. Corneal tissue was obtained following penetrating keratoplasty. Corneal scraping revealed no microorganisms. Giemsa stained smear showed multinucleated giant cells. Conjunctival, corneal scrapings and tissue were positive for herpes simplex virus - 1 (HSV) antigen. Corneal tissue was positive for HSV DNA by PCR. CONCLUSIONS: Atypical HSV keratitis can occur in contact lens wearers. A simple investigation like Giemsa stain may offer a clue to the diagnosis.

Impression cytology-proven corneal stem cell deficiency in patients after surgeries involving the limbus.

PURPOSE: To report three cases of limbal stem cell deficiency (confirmed by impression cytology) that followed multiple pterygium surgeries and therapeutic penetrating keratoplasty. METHODS: The first case, after multiple pterygium surgeries, presented with corneal scarring and thickened epithelium with vascularization sparing the central cornea in the right eye and involving the entire cornea in the left eye. The second case presented with superficial scarring and extensive vascularization after failed therapeutic graft performed for a large perforated corneal ulcer. The third case was a clear graft performed for a progressing fungal ulcer with signs of conjunctivalization inferotemporally. Limbal stem cell deficiency was clinically suspected in all of these cases. RESULTS: Goblet cells with mucin globules were found on the corneal surface by impression cytology in all three cases. CONCLUSIONS: We report three cases of limbal stem cell deficiency (proven by impression cytology) that followed multiple pterygium surgeries and therapeutic penetrating keratoplasty. Surgical insult to the limbus is the predisposing factor for stem cell damage in these cases. Involvement of the limbus by infection and use of intensive medications are probable contributing factors for stem cell damage in cases of therapeutic penetrating keratoplasty.

Enzymatic, clinical and histologic evaluation of corneal tissues in experimental fungal keratitis in rabbits.

Mycotic keratitis, being frequently refractive to most of the currently available antifungal therapy, continues to pose a therapeutic challenge to the clinician. In keratitis of infectious etiology stromal dissolution may be brought about by a combination of agent and host factors. An understanding of the source and nature of corneal tissue damage is essential for evolving more effective therapeutic modalities in the treatment of fungal keratitis. In the present study, we have characterized the extracellular proteases produced in vitro by corneal fungal pathogens namely the Aspergillus flavus and Fusarium solani when collagen was provided as the sole nitrogen source. In addition, fungal infected rabbit corneas were investigated for proteolytic activities and nature of inflammatory reaction. Gelatin zymography detected protease bands with molecular mass ranging from 100 to 200 kDa in the culture extracts of A. flavus, and a single major band of molecular mass approximately 200 kDa in the culture extracts of F. solani. A basal proteolytic activity of mass 65 kDa was visualized in all uninfected and infected rabbit corneal extracts. Infected corneas in addition revealed the presence of additional proteolytic species of mass 92 and 200 kDa. The enzyme inhibitory profile suggested that fungal cultures in vitro contained predominantly serine protease activity and to a lesser extent metalloprotease activity. However, fungal infected corneal homogenates showed the presence of metalloproteinase activity alone, the enzymatic activities entirely being sensitive to ethylene diamine tetra acetate (EDTA), a metalloprotease inhibitor. Interestingly, the serine proteolytic activity detected in fungal cultures in vitro was not present in the fungal infected corneas in vivo. However, the possible role of fungal serine proteases in the activation of corneal matrix metalloproteinases (MMPs) cannot be ruled out. Based on the criteria of molecular mass, proteolytic activity in the presence of calcium at neutral pH, and sensitivity to inhibition by a metalloprotease inhibitor, the 65 and 92 kDa gelatinases were identified as MMP 2 and MMP 9, respectively. The expression of 92 and 200 kDa gelatinases correlated positively with the amount of polymorphonuclear cells present in the infected tissues. Activated resident corneal cells or inflammatory cells may largely contribute to the increased proteolytic activities in fungal infected corneas resulting in tissue matrix degradation in fungal keratitis.

Bilateral infectious keratitis after laser in situ keratomileusis: a case report and review of the literature.

OBJECTIVE: To report a case of bilateral infectious keratitis after simultaneous bilateral laser in situ keratomileusis (LASIK) and to explore appropriate preventive, diagnostic, and therapeutic measures. DESIGN: Interventional case report and literature review. INTERVENTION: A 22-year-old woman had bilateral corneal infiltrates after simultaneous bilateral LASIK. The same set of instruments was used for surgery on both eyes. Corneal scrapings from the edge of the infiltrate and underneath the flap were taken for microscopic examination and inoculation on culture media. Treatment consisted of irrigation of stromal bed with amikacin sulphate (2.5%) solution along with half hourly instillation of amikacin (2.5%) and cefazolin (5%) eye drops. MAIN OUTCOME MEASURES: Causative organism and response to medical treatment. RESULTS: Culture revealed a significant growth of Mycobacterium chelonae from the corneal scrapings of both eyes. There was progressive thinning of corneal stroma in the right eye requiring cyanoacrylate tissue adhesive application. The left eye showed progressive worsening after initial response and required penetrating keratoplasty. CONCLUSIONS: The risk of bilateral sight-threatening complications must be kept in mind when contemplating bilateral simultaneous LASIK. Nontuberculous mycobacteria should be considered as an etiologic agent in cases of infectious keratitis occurring after LASIK. Microbiology work-up of a specimen collected directly from the site of lesion can help in early diagnosis and institution of appropriate therapy.

Neuronal apoptosis in herpes simplex virus - 1 encephalitis (HSE).

Herpes simplex virus infections are encountered often due to their ubiquitous nature. Common sites involved include skin, mucous membrane, genitalia, eye and the nervous system. HSV infection of the central nervous system can be life threatening. Little is known about the pathogenesis of this cataclysmic disease, at the cellular level. Virus induced apoptosis may play a role in the molecular pathogenesis of encephalitis. This study aims to detect the presence of apoptosis: a) In the brain tissue obtained at autopsy from a patient who succumbed to Herpes simplex virus - 1 encephalitis (HSE) and b) In a human glioblastoma cell line (SNB 19). Wedge tissue samples were obtained from the inferior surface of the frontal lobe and fixed in buffered formalin. Tissue sections were stained with haematoxylin and eosin for histopathological analysis. An indirect immunoperoxidase assay was performed for the detection of HSV -1 antigen in the tissue sections. Apoptosis in the brain tissue was detected employing the TUNEL assay (Terminal deoxynucleotidyl Transferase (TdT) mediated deoxy Uridine Triphosphate Nick End Labeling) using a commerically available kit (TdT Fragel DNA fragmentation detection kit, Oncogene Research Products, CA). HSV-1 induced apoptosis of SNB 19 cells were detected in-vitro by: a) Membrane blebbing assay and b) Hoechst 33258 staining. Classical features of viral encephalitis including the presence of intranuclear inclusions, neuronal loss and perivascular cuffing were seen in the tissue sections. The immunoperoxidase assay revealed the presence of abundant viral antigen in the neurons, microglial and satellite cells. TUNEL assay revealed many apoptotic neurons, microglial and satellite cells. In-vitro assays showed evidence of HSV-1 induced apoptosis in the SNB 19 cell line. These results suggest that virus induced apoptosis may play a role in the molecular pathogenesis of HSE. Further studies are warranted to elucidate the role of HSV-1 induced apoptosis, especially employing cell lines of neuronal origin.