Biomedical subjects

Harminder S Dua

Publications and source records attributed to Harminder S Dua.

At least 19 recordsLinked to original sources

PubMed2006

Morphological characteristics of the limbal epithelial crypt.

AIM: In 2005 we reported the discovery of a novel anatomical structure at the limbus, which we termed the limbal epithelial crypt (LEC). The purpose of this study was to further evaluate the distribution, immunophenotypical, and ultra structural characteristics of the LEC as a putative niche of stem cells. METHODS: Sequential histological sections of human corneo-scleral limbal rims were examined for the presence and distribution of the LEC. Immunophenotypical characterisation of the LEC cells using a panel of antibodies of interest was undertaken. Transmission electron microscopy of the LEC was used to examine the ultra structural and morphometric features of cells within the LEC and adjacent limbus. RESULTS: A total of 74 LECs were identified in eight corneo-scleral rims. These varied in number, size and distribution within rims. Cells within the crypt demonstrated the following phenotype: CK3-/CK19+/CD 34-/Vimentin+/p63+/Connexin 43+/MIB1 (Ki67)-. Presence of Cx43 was also demonstrated in the rete pegs adjacent to the LEC. Basal cells of the LEC were significantly smaller than basal cells found in adjacent rete pegs and also smaller than suprabasal limbal and central corneal epithelial cells (p<0.05). Morphologically they had a high nuclear:cytoplasmic ratio and were adherent to the underlying basement membrane by means of complex convolutions of cytoplasmic processes. CONCLUSIONS: LECs are sparse but a consistent finding in the human corneo-scleral limbus. The LEC contains a unique sub-population of cells expressing several characteristics that are consistent with it representing a putative stem cell niche.

Cell Size↗

PubMed2006

Alcohol delamination of the corneal epithelium: an alternative in the management of recurrent corneal erosions.

PURPOSE: To investigate the efficacy of alcohol delamination in the management of recurrent corneal erosions (RCEs). DESIGN: Prospective single-center consecutive descriptive case series. PARTICIPANTS: Twelve patients with RCEs who did not respond to conservative management were treated with alcohol delamination. METHODS: A consecutive case series of 12 patients with RCEs who did not respond to conservative management were treated by alcohol delamination. A pain score was generated based on a visual analog scale of pain intensity. The duration of pain and frequency were also recorded. Patients were followed up at 1 week, 4 weeks, 3 months, 6 months, and 1 year and then at yearly intervals and monitored for recurrence of symptoms and corneal morphology. The removed epithelial sheet was examined by electron microscopy in 4 patients. INTERVENTION: The affected area of epithelium was peeled off after an application of 20% alcohol for 40 seconds under topical anesthesia. Eyes of patients were treated with an antibiotic and preservative-free artificial tear medication, and a bandage contact lens was inserted until epithelial healing was complete. MAIN OUTCOME MEASURES: Frequency of recurrence of erosions and duration and intensity of symptoms after alcohol delamination were studied. RESULTS: Eleven of the 12 eyes of patients had dramatic relief of symptoms over the follow-up period, ranging from 6 to 40 months. Eight patients were symptom free, and 1 patient had 2 mild symptom episodes in the first posttreatment month before becoming symptom free. The average follow-up period was 23.5 months. There were no residual effects from the application of alcohol noted in any patient. Electron microscopy of removed epithelium showed features of the underlying pathology. The separation of the epithelium occurred at the interface of the subepithelial abnormal deposit and the surface of Bowman's zone. CONCLUSION: Alcohol delamination appears to be a novel, simple, inexpensive treatment for RCEs. Unlike other methods, the removed epithelium is available as a sheet that may be subjected to further examination, though some of the changes observed may reflect the effect of alcohol on the epithelium.

Adult↗

PubMed2006

Epithelial dendritic cell distribution in normal and inflamed human cornea: in vivo confocal microscopy study.

PURPOSE: To evaluate dendritic cell (DCs) density, distribution, and morphology in central corneal and limbal epithelium in normal subjects and patients with immune-mediated corneal inflammation using in vivo confocal microscopy (IVCM). DESIGN: Comparative case-controlled, observational confocal microscopy study. METHODS: A total of 135 eyes of 135 patients were investigated. Group 1 (normal eyes) included 45 eyes of 45 healthy volunteers, group 2 photorefractive keratectomy (PRK-treated eyes) included 45 myopic eyes of 45 patients treated with PRK, and group 3 (inflamed eyes) comprised 45 eyes of 45 patients affected by immune-mediated corneal inflammation. The central cornea and limbus were examined for epithelial dendritic-shaped cells using laser scanning IVCM. DCs density was calculated using image analysis software. RESULTS: Cells with a branching dendritic morphology were visualized in the basal epithelial layer, basal lamina, and subbasal nerve plexus, in the central cornea, and in the basal layer and basal membrane of the limbal epithelium. The limbal epithelium demonstrated DCs in 93.3%, 89%, and 97.7% of eyes in group 1, 2, and 3, respectively (P = ns). Central epithelial DCs were observed in 20.0% and 13.3% of eyes in group 1 and 2 (P = ns), while in 93.3% of eyes in group 3 (P < .001). DCs were found to be significantly higher at the limbus compared with central cornea in each group (P < .001). Cell densities observed in group 3 were significantly greater than groups 1 and 2, at both locations (P < .05). CONCLUSIONS: Laser scanning IVCM is a useful method for evaluating epithelial DCs distribution at the limbus and central cornea in both healthy and diseased eyes.

Adult↗

PubMed2006

Proteomic analysis of amniotic membrane prepared for human transplantation: characterization of proteins and clinical implications.

Amniotic membrane is commonly exploited in several surgical procedures. Despite a freeze preservation period, it is reported to retain wound healing, anti-angiogenic, antiinflammatory and anti-scarring properties; however, little is known about the active protein content. 2-DE analysis of transplant-ready amniotic membrane (TRAM) was performed. The effects of preservation and processing on amnion proteome were investigated, and the major proteins in the TRAM characterized using mass spectrometry and immunoblotting. This identified a spectrum of proteins including thrombospondin, mimecan, BIG-H3, and integrin alpha 6. Preservation compromises cellular viability resulting in selective elution of soluble cellular proteins, leaving behind extracellular matrix-associated and cell structural proteins. A number of key architectural proteins common to the architecture of the ocular surface were demonstrated in AM, which are involved in homeostasis and wound healing. Handling procedures alter the protein composition of amniotic membrane prepared for transplantation. Without standardization, there will be inter-membrane variation, which may compromise the desired therapeutic effect of transplant ready amniotic membrane.

Amnion↗

PubMed2006

Dysfunctional tear syndrome: a Delphi approach to treatment recommendations.

PURPOSE: To develop current treatment recommendations for dry eye disease from consensus of expert advice. METHODS: Of 25 preselected international specialists on dry eye, 17 agreed to participate in a modified, 2-round Delphi panel approach. Based on available literature and standards of care, a survey was presented to each panelist. A two-thirds majority was used for consensus building from responses obtained. Treatment algorithms were created. Treatment recommendations for different types and severity levels of dry eye disease were the main outcome. RESULTS: A new term for dry eye disease was proposed: dysfunctional tear syndrome (DTS). Treatment recommendations were based primarily on patient symptoms and signs. Available diagnostic tests were considered of secondary importance in guiding therapy. Development of algorithms was based on the presence or absence of lid margin disease and disturbances of tear distribution and clearance. Disease severity was considered the most important factor for treatment decision-making and was categorized into 4 levels. Severity was assessed on the basis of tear substitute requirements, symptoms of ocular discomfort, and visual disturbance. Clinical signs present in lids, tear film, conjunctiva, and cornea were also used for categorization of severity. Consensus was reached on treatment algorithms for DTS with and without concurrent lid disease. CONCLUSION: Panelist opinion relied on symptoms and signs (not tests) for selection of treatment strategies. Therapy is chosen to match disease severity and presence versus absence of lid margin disease or tear distribution and clearance disturbances.

Algorithms↗

PubMed2006

Amniotic membrane for ocular surface reconstruction: donor variations and the effect of handling on TGF-beta content.

PURPOSE: Amniotic membrane (AM) transplantation is an accepted procedure in ocular surgery. However, little is known of the interdonor and intradonor variability within the membrane. In addition, the effects of the methods of processing, storage, and preoperative preparation on the membrane are not fully elucidated. The purpose of this study was to use TGF-beta as an example to investigate interdonor and intradonor variability and to determine the effect of "handling " on TGF-beta1 within fresh, processed and stored, and transplantation-ready AM (TRAM). METHODS: Seventeen human AMs, both fresh and handled, were analyzed for TGF-beta1 by real-time polymerase chain reaction, immunohistochemistry, SDS-PAGE, and Western blotting. RESULTS: TGF-beta1 was the highest normalized expressed isoform of TGF-beta in all samples, but it varied between membranes of different donors and at different sites within the same membrane. The highest concentration was noted in the spongy layer. Removal of the spongy layer successfully removed the bulk of TGF-beta1 from TRAM. Latency-associated protein (LAP) and a latent TGF-beta-binding protein (LTBP) were also detected. CONCLUSION: TGF-beta1 is present in various regulatory forms in the AM. A degree of intermembrane and intramembrane variation is modified by handling. Unless a standardized protocol is adopted that delivers a membrane with consistent constituents, clinical outcomes may vary and comparisons may be invalid.

Amnion↗

PubMed2005

Optimised two-dimensional electrophoresis procedures for the protein characterisation of structural tissues.

The protein analysis of structural tissues is typically highly problematic. Amniotic membrane displays unique wound healing and anti-scarring properties; however, little is known concerning its active protein content. The structural nature of amniotic membrane necessitated development and extensive optimisation of the entire two-dimensional (2-D) workflow. Proteins were extracted using powerful solubilisation buffers and analysis carried out using 2-D electrophoresis followed by mass spectrometry (MS) identification. Preservation and processing resulted in prefractionation of soluble from structural and membrane-associated proteins. Enhanced protein solubility was achieved by cysteine blocking using both N,N-dimethylacrylamide (DMA) alkylation and bis(2-hydroxyethyl) disulphide (HED); an alternative procedure for the effective application of HED is demonstrated. The benefits of precipitation and cup-loading versus in-gel rehydration were also assessed, with procedures for the employment of HED with the latter described. Following optimisation, a representative sample 21 proteins were identified from amniotic membrane using MS verify procedures were MS-compatible. Our results demonstrate that techniques for the reproducible separation of proteins from a proteinaceous structural tissue have been optimised. Briefly, proteins are extracted using a thiourea/urea extraction buffer containing carrier ampholytes, dithiothreitol (DTT), and 3-(cyclohexylamino)-1-propanesulfonic acid (CHAPS). After DMA alkylation, proteins were precipitated (using the 2-D clean-up kit from Amersham Biosciences) and resolubilised in extraction buffer containing a lower concentration of DTT. Samples were either cup-loaded onto rehydrated HED-containing strips or rebuffered into HED-containing buffer followed by in-gel rehydration.

Amnion↗

PubMed2005

Imatinib as a cause of cystoid macular edema following uneventful phacoemulsification surgery.

Cystoid macular edema (CME) is an important cause of visual impairment following phacoemulsification surgery. Imatinib is a new drug that is being used as adjunctive therapy in the management of various malignancies. A reported ocular side effect of this drug is spontaneous retinal edema. We report the case of a patient on imatinib who developed significant premature CME following uneventful phacoemulsification surgery. This resolved soon after cessation of imatinib therapy, and there was an improvement in visual acuity.

Antineoplastic Agents↗

PubMed2005

Amniotic membrane use in ophthalmology.

PURPOSE OF REVIEW: The purpose of this review is to describe the most recent and relevant clinical and experimental data about the use of amniotic membrane in ophthalmology. RECENT FINDINGS: The amniotic membrane is a biologic tissue that has been used as a graft for corneal and conjunctival reconstruction in a variety of ocular surface diseases. It is avascular and possesses anti-angiogenetic, anti-scarring and antiinflammatory properties. It is not a substitute but rather a substrate upon which cells can migrate and regenerate, forming new and healthy tissue. The amniotic membrane can also be used as a biologic patch, as a bandage, to treat acute inflammatory disorders. With the development of cell therapy, amniotic membrane can be also used as a carrier of limbal stem cells or their progeny, cultivated in vitro. SUMMARY: Amniotic membrane use in ophthalmic surgery has been shown to provide an alternative for corneal and conjunctival reconstruction in many clinically challenging situations; however, there is still a lack of scientific evidence based on randomized comparative studies to prove that its use is better than other alternative therapies for ocular surface reconstruction.

Amnion↗

PubMed2005

The spectrum of antimicrobial peptide expression at the ocular surface.

PURPOSE: Antimicrobial peptides are the eukaryotic analogues of antibiotics. In addition to their antimicrobial activity, these peptides can signal to host cells and are therefore intermediaries between the innate and adaptive immune systems. Results in a prior study showed that beta-defensins-1 and -2 are made by ocular surface epithelial cells. In the present study, a survey was made of antimicrobial peptide expression, including 17 previously described members of the beta-defensin family, at the surface of the human eye. METHODS: Total RNA was obtained from 43 fresh and cultured corneal and conjunctival samples, including 9 samples from patients with clinical infections. The expression of 21 antimicrobial peptides was determined using reverse transcription-PCR. Where detected, relative expression was quantitated using real-time PCR. RESULTS: Expression of 7 of the 21 antimicrobial peptides investigated, beta-defensin-1 to -4, liver expressed antimicrobial peptide (LEAP)-1 and -2, and LL37/cathelicidin, were detected frequently in samples of ocular surface epithelia. Distinct but overlapping profiles of expression were detected in cornea and conjunctiva, with expression of beta-defensin-3 and -4 and LEAP1 and -2 most common in cultured corneal epithelia. Expression of beta-defensin-3 was detected in a greater percentage of corneal and conjunctival samples with infection. CONCLUSIONS: Together with known lacrimal antimicrobial activities, these results extend the knowledge of antimicrobial activity at an important mucosal site, the ocular surface, allowing synergistic interactions to be investigated. The findings has significant implications both for the understanding of the normal homeostasis of mucosal surfaces and for antimicrobial and anti-inflammatory therapies.

Adolescent↗

PubMed2005

Laser scanning tomography of the optic nerve head in a normal elderly population: the Bridlington eye assessment project.

PURPOSE: To assess optic nerve head topographic parameters using the Heidelberg Retina Tomograph (HRT) II (Heidelberg Engineering GmbH, Dossenheim, Germany) in a normal elderly population. METHODS: Optic nerve head analysis of 918 eyes of 459 normal elderly patients was performed. All patients were consecutive in a cohort screened for eye disease. Normal subjects were defined with a normal visual field on automated suprathreshold screening, intraocular pressure less than 22 mmHg, and minimum corrected visual acuity of 6/12. All optic discs were contoured by two investigators and the mean parameters analyzed. The effects of age, sex, and disc size were assessed. RESULTS: Subjects' (262 women and 197 men) mean age was 72.6 +/- 5.1 (SD) years (range, 65.5-89.3). Mean +/- SD global disc area, cup/disc area ratio, and neuroretinal rim area were 1.98 +/- 0.36 mm2, 0.22 +/- 0.14, and 1.52 +/- 0.31 mm2, respectively. Disc area did not differ significantly based on eye side or sex. The women were found to have a significantly larger rim volume, mean retinal nerve fiber layer (RNFL) thickness, and cross-sectional area than the men and tended to have smaller cup areas/volumes and cup/disc area ratios. Most tomography parameters were found to be significantly influenced by disc size. CONCLUSIONS: To the authors' knowledge, this is the first large study of optic nerve head parameters in the elderly normal population using the HRT II. This age range is particularly relevant to glaucoma detection and pertinent to discriminant analyses separating normal subjects from glaucoma in screening for the disease. Given the systematic differences between the parameters in men and women, reference ranges should be quoted by sex.

Aged↗

PubMed2005

Asymmetry in optic disc morphometry as measured by heidelberg retina tomography in a normal elderly population: the Bridlington Eye Assessment Project.

PURPOSE: To define the normal range of asymmetry in optic disc parameters measured by the Heidelberg Retina Tomograph (HRT II; Heidelberg Engineering GmbH, Dossenheim, Germany) in a normal elderly population. METHODS: Optic disc analysis of 918 eyes of 459 normal elderly patients was performed. All patients were consecutive in a cohort screened for eye disease. Normality was defined with a normal visual field on automated suprathreshold screening, intraocular pressure less than 22 mm Hg, and minimum corrected visual acuity of 6/12. Asymmetry measures were calculated by subtracting the values of the smaller disc from those of the larger disc. RESULTS: Subjects' mean age (262 female and 197 male) was 72.6 years (range, 65.5-89.3). There was no significant difference in disc area or rim area between the right and left eyes. Neither rim-to-disc area ratio asymmetry nor rim measurement asymmetries were significantly affected by age or sex. Rim-to-disc area ratio asymmetry was much less affected by the increasing difference in disc size than was absolute rim asymmetry. The 2.5th and 97.5th percentile limits of normality for the rim-to-disc area ratio asymmetry in the global and temporal-inferior analyses were -0.212 and 0.154, and -0.331 and 0.261, respectively. CONCLUSIONS: The normal range of parameter asymmetry in an age group relevant to glaucoma may be useful in the discrimination of normal from early glaucoma. Asymmetry analysis may improve discriminatory ability by reducing parameter variability based on disc size. The rim-to-disc area ratio asymmetry measure is likely to be the most useful parameter in describing normality with consistency.

Aged↗

PubMed2004

Apoptosis in proliferative vitreoretinopathy.

PURPOSE: To study the involvement of apoptosis using different apoptosis markers in PVR pathogenesis. METHODS: The presence of mRNA coding for Fas, Fas ligand (FasL), and TNF-related apoptosis inducing ligand (TRAIL) was investigated in vitreous samples from 46 consecutive patients-25 with PVR, 11 with retinal detachment (RD) not complicated by PVR, and 10 with macular hole (MH)-using RT-PCR. From previously examined vitreous samples, 21 PVR, 9 RD, and 10 MH were examined for their levels of TGF-beta2 protein with sandwich ELISA kits. Five epiretinal membranes excised from five patients with PVR were also examined for apoptotic cell death using the terminal deoxytransferase (TdT) mediated dUTP-biotin nick end labeling (TUNEL) technique. RESULTS: FAS mRNA was detected in 72% of patients with PVR, 55% of patients with RD and 20% of patients with MH. TRAIL mRNA was detected in 67% of patients with PVR, 89% of patients with RD, and 20% of patients with MH. FasL mRNA was detected in 20% of patients with PVR, 9% of patients with RD, and 10% of patients with MH. The median levels of Fas and TRAIL mRNA were significantly higher (P < 0.05) in patients with PVR than in those with MH hole but between patients with PVR and those with RD the difference was not significant (P > 0.05). A significant difference was detected between RD and MH for TRAIL mRNA levels (P = 0.008). For FasL, no significant difference between groups was found. TGF-beta2 was detected in all investigated vitreous samples. A significant difference was found between the PVR and MH groups (P = 0.001) and between the RD and MH groups (P = 0.004), but not between the PVR and RD groups (P < 0.05). The level of TGF-beta2 was significantly correlated to the level of TRAIL mRNA (r = 0.86), but no correlation was found between TGF-beta2 and Fas mRNA levels (r = 0.21). Four of five examined PVR epiretinal membranes showed positive staining for apoptotic cells using the TUNEL technique. CONCLUSIONS: Apoptosis is one of the mechanisms that is involved in PVR pathogenesis. Different apoptosis markers suggest different pathways occur in PVR, including Fas/FasL, TRAIL, and TGF-beta2 mediated processes.

Adult↗

PubMed2004

Limbal stem cell transplantation.

The past two decades have witnessed remarkable progress in limbal stem cell transplantation. In addition to harvesting stem cells from a cadaver or a live related donor, it is now possible to cultivate limbal stem cells in vitro and then transplant them onto the recipient bed. A clear understanding of the basic disease pathology and a correct assessment of the extent of stem cell deficiency are essential. A holistic approach towards management of limbal stem cell deficiency is needed. This also includes management of the underlying systemic disease, ocular adnexal pathology and dry eye. Conjunctival limbal autografts from the healthy contralateral eye are performed for unilateral cases. In bilateral cases, tissue may be harvested from a cadaver or a living related donor; prolonged immunosuppression is needed to avoid allograft rejection in such cases. This review describes the surgical techniques, postoperative treatment regimes (including immunosuppression for allografts), the complications and their management. The short and long-term outcomes of the various modalities reported in the literature are also described.

Clinical Trials as Topic↗

PubMed2003

Infliximab in the treatment of refractory posterior uveitis.

PURPOSE: To determine the efficacy and safety of infliximab in the treatment of refractory posterior uveitis. DESIGN: Noncomparative interventional case series. PARTICIPANTS: Five patients with posterior uveitis were treated: 3 had Behçet's syndrome, and 2 had idiopathic posterior uveitis. INTERVENTIONS: Patients with sight-threatening uveitis refractory to other immunosuppressive agents were treated with infliximab. MAIN OUTCOME MEASURES: Intraocular inflammation, by using binocular indirect ophthalmoscopy score, retinal vasculitis, and visual acuity. Adverse effects of infliximab were documented. RESULTS: Within 2 weeks of the first infusion of infliximab, 4 of 5 patients showed marked improvement in vitreous haze and visual acuity. By the 6-month follow-up, the same four patients had achieved remission of posterior uveitis and had successfully withdrawn all other immunosuppressive therapy. Further infusions of infliximab were required in 3 patients. One patient developed ocular and systemic tuberculosis, which responded to antituberculous treatment. CONCLUSIONS: Infliximab is effective in the treatment of sight-threatening refractory posterior uveitis. However, patients should be thoroughly screened for tuberculosis before treatment and followed up closely during and after therapy with infliximab.

Adult↗

PubMed2003

Alcohol debridement of the corneal epithelium in PRK and LASEK: an electron microscopic study.

PURPOSE: To determine the plane of cleavage of the corneal epithelium and smoothness of underlying stroma, after alcohol debridement in photorefractive keratectomy (PRK) and laser subepithelial keratectomy (LASEK). METHODS: The epithelial flap from six patients undergoing alcohol delamination of corneal epithelium before PRK and the epithelium and stroma from three eye bank donor eyes were fixed and processed for transmission (TEM) and scanning electron microscopy (SEM). The smoothness of the underlying stroma was studied by SEM and the plane of cleavage was determined by morphologic examination and morphometric measurements of basement membrane attached to the epithelial flap, using image-analysis software. RESULTS: A very smooth stromal bed, ideal for PRK was seen in the stroma of all three eye bank donor eyes after alcohol delamination. The plane of cleavage was determined to be at the hemidesmosomal attachments, including the most superficial part of the lamina lucida of the basement membrane. CONCLUSIONS: Alcohol delamination of the corneal epithelium before PRK or LASEK consistently results in a very smooth cleavage at the level of the hemidesmosomal attachments, including the superficial lamina lucida. It leaves behind a very smooth surface, which is ideal for PRK. It also allows for an intact epithelial flap to be lifted as a sheet from the corneal surface and hence is ideally suited for the LASEK technique.

Basement Membrane↗

PubMed2003

Expression of CD34 and L-selectin on human corneal keratocytes.

PURPOSE: To investigate the expression of CD34, a hematopoietic stem cell marker and an adhesion molecule, and its ligand L-selectin in the human cornea. METHODS: Seventeen normal adult human corneal specimens were studied by immunohistochemistry using a panel of monoclonal antibodies against all three classes of the hematopoietic stem cell marker CD34 and its ligand L-selectin. An additional six corneal specimens were used for protein extraction and analysis by Western blotting, using the CD34 and L-selectin antibodies. PCR was used to determine expression of mRNA for CD34 and L-selectin in the corneal specimens. RESULTS: Only corneal keratocytes showed positive immunostaining for all three classes of CD34. Western blotting confirmed the expression of CD34 by these cells and mRNA expression for CD34 in the corneal stroma was demonstrated by PCR. For L-selectin, positive staining around keratocytes was noted on immunohistochemistry but L-selectin could not be detected either by Western blotting or PCR. CONCLUSIONS: Normal human corneal keratocytes express all three classes of CD34. The expression of this adhesion molecule on corneal keratocytes suggests that it may have a role in keeping the keratocytes anchored in their microniche, between the collagen lamellae. The positive staining for L-selectin found by immunohistochemistry but not by Western blotting or PCR would indicate the presence of either another ligand from the selectin family or a cross-reactive epitope on corneal keratocytes.

Antibodies, Monoclonal↗

PubMed2002

Role of choroidal drainage in therapeutic keratoplasty.

PURPOSE: To discuss the role of choroidal drainage in the management of positive vitreous pressure during therapeutic keratoplasty for patients with perforated corneal ulcers. METHODS: Over a 2-year period, 8 of 36 (22%) consecutive patients with therapeutic grafts presented with a shallow anterior chamber during or immediately after surgery. These patients underwent choroidal drainage for formation of the anterior chamber. In 5 of them choroidal drainage was done intraoperatively when there was significant positive vitreous pressure and the anterior chamber could not be formed. Three patients had drainage within a week postoperatively for persistent shallow anterior chamber when ultrasonogram showed choroidal detachment. RESULTS: Of the eight cases, seven drained fluid and the chamber could be reformed well. One was a dry tap and the chamber did not reform completely. CONCLUSION: Choroidal detachment (CD) is a previously unpublished cause for positive vitreous pressure in therapeutic keratoplasty for perforated corneal ulcers. In these situations suprachoroidal drainage can be considered as an option for the reformation of the anterior chamber. We recommend that a preoperative B-scan ultrasound be included in the workup of all corneal perforations and that intraoperative drainage of the fluid is considered in cases with significant positive vitreous pressure and confirmed CD.

Anterior Chamber↗