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Introduction Since the beginning of the COVID-19 pandemic there has been some debate regarding the risk of transmission through tissue transplantation and tissue banking processes. Aim of the study To analyze the changes that SARS-CoV-2 has caused regarding the harvesting of corneal donor tissue and eye bank activities in Germany. Methods A questionnaire was provided to 26 eye banks in Germany, consisting of questions about adaptations made in the screening of potential donors and the harvesting of corneal tissue following the pandemic spread of SARS-CoV-2. Results Eighteen eye banks actively reduced recruitment of donors and two banks ceased all activity. Additional diagnostic screening was performed in eight banks, using conjunctival swabs and/or nasopharyngeal swabs. In six eye banks, additional protective measures, such as FFP2 masks and/or facial shields, were implemented. Overall, a mean reduction in the number of obtained donor tissues of 17% was observed. Discussion Conjunctival and/or nasopharyngeal swabs of donors have been implemented by a minority. Reasons for not performing additional tests may be moderate sensitivity and lack of validation for postmortem use of RT-PCR testing. Also, the hazard of SARS-CoV-2 entering the corneal donor pool with subsequent transmission might be perceived as theoretical. Face shields provide a sufficient barrier against splash and splatter contamination but may be insufficient against aerosols. Additional face masks would provide support against aerosols, but it remains debatable if corneal harvesting can be considered an aerosol-producing procedure. In the future we expect to see changes in current guidelines because of a surge in scientific activities to improve our understanding of the risks involved with cornea donation in the COVID-19 pandemic, and because current practice may reduce the availability of donor corneas due to new exclusion criteria while the demand remains unchanged.

To assess corneal endothelial cell (CEC) quantity and quality in eye-bank prepared lamellar grafts for Descemet Membrane Endothelial Keratoplasty (DMEK) from organ cultured donor corneas that have not undergone de-swelling by media supplementation with dextran. Prior to graft preparation, corneas that had not undergone de-swelling (n = 30) were placed into fresh storage medium without dextran (KMI). Corneas in the control group (n = 30) were placed in dehydration medium containing 5% dextran (KMII). Subtotal stripping of Descemet’s membrane (DM) was performed manually. Following graft preparation, 10 corneas of each group were cultured further in their respective medium for 24 h, 72 h, or 120 h, respectively. Before and after DM stripping, as well as at the end of culture, CEC numbers were obtained. At the end of culture, CEC morphology was graded using a scoring system and CEC metabolism was assessed by detection of adenosine triphosphate. At 24 h after DM stripping, mean CEC counts (in cells/mm2) were 2204 in corneas stored in KMII, and 2391 in corneas stored in KMI (p = 0.003). This corresponds to a mean relative CEC loss of 12.4% with dextran versus 9.7% without dextran (p = 0.04). At 72 h, CEC counts were 1946 in KMII, and 2289 in KMI (p = 0.004). This corresponds to CEC loss of 23% with dextran versus 14% without dextran (p = 0.009). At 120 h, CEC counts were 2047 in KMII, and 2230 in KMI (p = 0.14). This corresponds to CEC loss of 22.7% with dextran versus 17.2% without dextran (p = 0.14). Also, at 120 h after DM stripping, 6/10 corneas fell below a threshold of 2000 cells/mm2 if stored in medium containing dextran, versus 1/9 corneas if stored without dextran (p = 0.003). Morphological assessment of CEC quality revealed equal scores for cell polymorphism (median = 1), granulation (median = 0) and segmentation (median = 1) in all groups. Lower ATP/protein ratios were observed in corneas stored in medium without dextran at 24 h (p

Purpose: To measure corneal endothelial cell (EC) quality and quantity following Descemet membrane (DM) stripping of human donor corneas and continued storage in organ culture medium containing dextran.Methods: DM stripping was performed in 30 organ cultured, corneoscleral discs. Corneas were divided into 3 groups of 10 corneas each. Baseline mean EC density (cells/mm2) was 2,372 (SD ± 259) in group 1, 2,540 (SD ± 266) in group 2, and 2,665 (SD ± 263) in group 3. Following subtotal DM stripping, culture was continued at 31°C for 24 hours (group 1), 72 hours (group 2), and 120 hours (group 3), respectively. EC density was measured before stripping and at the end of culture. At the end of culture, corneal EC morphology was graded using a scoring system and EC viability was measured by detection of adenosine triphosphate.Results: At the end of culture, mean EC density was 2,159 (SD ± 293) in group 1, 1,946 (SD ± 182) in group 2, and 2,047 (SD ± 225) in group 3. This constitutes an EC loss of 9,1% (SD...

Purpose In this study, we investigated the associations between conjunctival (co) and intraocular (io) swabs and their implications for the contamination rates of organ-cultured corneas. Methods A total of 4177 swabs from 1054 corneas of 527 donors were acquired from the conjunctiva, after disinfection with 5% polyvinylpyrrolidone–iodine solution, and also from the anterior chamber after corneoscleral trepanation (io). Samples were incubated at 22.5 ± 2.5°C and 32.5 ± 2.5°C in thioglycollate broth for 14 days. Donor corneas were cultured in a closed system at 31°C. Microbial differentiation was performed for positive cultures. Results A higher temperature (32.5°C) and the intraocular swab retrieving localization led to significantly higher swab positive rates (32.5°C versus 22.5°C, odds 1.65, p

Before corneal transplant surgery, a deswelling process of organ-cultured corneas is required. This study compares the deswelling kinetics of corneas with an intact endothelial cell layer and disrupted or removed endothelium by measuring central corneal thickness (CCT) over time using anterior segment spectral domain optical coherence tomography.Ten donor pairs were cultured in organ culture. The right and left corneas were alternately assigned to one of 2 deswelling groups. Deswelling in the first group [endothelial group (EG)] was induced using a medium with dextran 5%. Corneas of the second group [nonendothelial group (NEG)] were deprived of their endothelial cell layer by trypsinization and were then placed in the same deswelling medium. CCT (mean ± SD) was measured by anterior segment spectral domain optical coherence tomography before deswelling (0 hours) and after 1, 2, 3, 6, 12, 24, 48, 72, and 144 hours. Deswelling kinetics was analyzed through the nonlinear platform in SAS/JMP11 Pro.Before deswelling, CCT was 1071.0 μm (±129.6 μm) and 1133.8 μm (±124.3 μm) in the EG and NEG, respectively. Minimum corneal thickness was obtained after 24 hours in the EG (531.9 ± 47.5 μm) and 6 hours in the NEG (645 ± 81.2 μm). CCT was significantly (P0.01) higher in the NEG than EG after more than 6 hours.Corneal dehydration after organ culture seems to be a multifactorial process, which not only depends on osmotic effects of the deswelling compound but also requires the presence of an intact endothelial cell layer.

Durch den hohen Bedarf und der deutlich geringeren Verfugbarkeit von Hornhauten des Auges besteht eine grose Hoffnung auf das Gelingen arztlicher Akquisegesprache mit Angehorigen zum Einverstandnis in eine Gewebespende. Neben der Steigerung des Erfolgs in der Spendergewinnung sollen Akquisegesprache schutzend fur Angehorige verlaufen und die Arbeitsbelastung des Fachpersonals gering gehalten werden. Diese Arbeit erfasst den Bedarf und Erwartungen an ein Kommunikationstraining zur Vorbereitung auf die Akquisetatigkeit. Im September und Oktober 2009 wurde unter allen Akquisearzten, die in der Hornhautbank arbeiten bzw. gearbeitet haben, eine Bedarfanalyse fur ein Kommunikationstraining vorgenommen. Auf 10-stufigen numerischen Rangskalen wurde das Ausmas der fachlichen, emotionalen und personlichen Vorbereitung, das Ausmas der Einschatzung eines Kommunikationstrainings als sinnvoll, notwendig und hilfreich sowie die durchschnittliche und hochste Belastung und Bereitschaft zur Ausubung der Akquise erfragt. Die Studienteilnehmer fuhlten sich fachlich, emotional und in ihrer personlichen Uberzeugung nur mittelmasig auf die Tatigkeit vorbereitet und erachteten ein Kommunikationstraining fur in hohem Mas sinnvoll, notwendig und hilfreich. Bei mittlerer durchschnittlicher Arbeitsbelastung mit kurzfristigen Hochbelastungsphasen bestand nur eine moderate Bereitschaft zur weiteren Ausfuhrung dieser Tatigkeit. Durch klare Hinweise auf eine nicht als ausreichend empfundene Vorbereitung auf die Akquisetatigkeit und als hoch empfundene Arbeitsbelastung wurde ein Kommunikationsseminar mit einem spezifischen Training der Akquisetelefonate entwickelt. Dieses Training entspricht bedarfsgemas sowohl den Wunschen und Erwartungen des arztlichen Personals als auch den am ehesten beeinflussbaren Variablen im Hinblick auf die Erfolgsquote bei der Spendenakquise.

We report the case of a now 6-year-old girl who was born with different abnormalities in each eye. The right eye showed a total sclerocornea. At the age of 4 years we performed a perforating keratoplasty. On the left eye a large staphyloma developed. The staphyloma was excised and a cornea with a scleral rim was fixed in. This transplant became cloudy under a conjunctival flap and blepharoplasty. In addition to the clinical follow-up, histological and immun-histochemical examinations of the corneas were carried out.

Purpose Descemet membrane (DM) endothelial keratoplasty has improved outcomes of corneal transplantation in patients with corneal endothelial disease. However, the procedure has been criticized for jeopardizing donor tissue during graft preparation. Standardization of this procedure may provide a way toward minimizing tissue loss. For this purpose, we propose the use of a novel tool. Methods Computerized numerical control milling was used to create a blunt instrument, which was used to remove endothelial cells within a defined area in the periphery of donor corneas. Trypan blue was used to stain denuded DM. Graft preparation was continued as per our standard protocol. Transmission electron microscopy was performed on the treated area, and endothelial cell counts were obtained. Results Use of the modified procedure resulted in delineation of a peripheral band of denuded DM, which readily stained with trypan blue. This provided increased visibility of DM during subsequent steps. Transmission electron microscopy confirmed that no structural deficits of DM were induced. Mean endothelial cell loss (±SD) at 24 hours after preparation was 63 (±130) cells per square millimeter in the group prepared with the use of the new instrument (n = 7), versus 116 (±107) cells per square millimeter in the group prepared without the new instrument (n = 7; P = 0.45). Conclusions The device presented here enhances visualization of DM during creation of the peripheral margin for subsequent lifting of the margin and stripping of the graft. This may increase success rates and shorten preparation times and learning periods for DM preparation. DM ultrastructure and endothelial cells were not negatively affected.

Purpose We compared the SLc Original (SLc) and One-Use Plus (OUP) microkeratomes for ultrathin Descemet's stripping automated endothelial keratoplasty (DSAEK) lamella preparation and storage, vis-a-vis accuracy, endothelial cell loss (ECL) and lamellar surface roughness (LSR). Methods Twenty-five human corneas were dissected with single-use heads of different sizes aiming for a posterior lamella (PL) thickness of 85 μm, after which they were incubated for 6 days in a 5% dextran medium. Before preparation (0 hr) and 1, 24, and 144 hr after dissection, ECL and corneal thickness (CCT) were measured by ultrasound pachymetry (USP) and optical coherence tomography (OCT). Lamellar surface roughness (LSR) was assessed by scanning electron microscopy (SEM) and evaluated by two masked observers. Results Prior to cutting, CCTs did not differ between OCT and USP measurements, with a high correlation between the two modalities (r2 = 0.8; p

Purpose Endothelial assessment is crucial in the release of corneas for grafting. We retrospectively analysed the role of endothelial morphology parameters in predicting endothelial cell loss during organ culture. Methods Human donor corneas were cultured in minimal essential medium with 2% fetal calf serum and antibiotics. Initial endothelial morphology was assessed microscopically using score parameters polymegethism (POL), pleomorphism (PLE), granulation (GRA), vacuolization (VAC), segmentation of cell membranes (SEG), Descemet's folds (DF), trypan blue-positive cells (TBPC) and endothelial cell-free areas (ECFA). Some corneas were primarily rejected based on endothelial assessment. Endothelial cell density (ECD) was assessed at the beginning (I-ECD) and end of culture. Corneas were then placed in dehydration medium (as above + 5% dextran 500). In a subgroup, ECD was reassessed after dehydration. Endothelial cell loss during culture (ECL@Culture) and culture+dehydration (ECL-Culture&Dehydration) were calculated. Data were given as mean ± SD and analysed using multiple linear and logistic regression. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. Result I-ECD was 2812 ± 360/mm2 (n = 2356). The decision to reject a cornea due to endothelial assessment was associated negatively with I-ECD (OR = 0.77/100 cells, CI 0.7-0.82) and positively with ECFA (OR = 2.7, CI 1.69-4.35), SEG (OR =1.3, CI 1.01-1.68) and donor age (OR = 1.26/decade, CI 1.33-1.41). ECL@Culture was 153 ± 201/mm2 (n = 1277), ECL@Culture&Dehydration was 169 ± 183/mm2 (n = 918). ECL@Culture was associated positively with donor age, I-ECD, GRA and TBPC, and negatively with PLE, and DF. ECL@Culture&Dehydration was associated positively with age, sex, initial ECD, POL, PLE, VAC and TBPC. Conclusion Morphological parameters displayed associations with the exclusion of corneas from culture and with endothelial cell loss. Appropriate parameter selection for screening purposes may help improve graft quality.

We compared the hand-guided Moria Carriazo-Barraquer (CBm) microkeratome with the fully automatic SLc microkeratome for Descemet's stripping automated endothelial keratoplasty (DSAEK)-lamella preparation and storage, vis-à-vis accuracy, endothelial cell loss (ECL), and lamellar surface roughness (LSR).A total of 18 human corneas were dissected with both the 300 μm CBm multi-use (n = 9) and the 300 µm SLc (n = 9) single-use heads, after which they were incubated for 6 d in a 5% dextran medium. Before preparation (0 h) and 1, 24, and 144 h after dissection, ECL and corneal thickness (CT) were measured by ultrasound pachymetry (USP) and optical coherence tomography (OCT). LSR was assessed by scanning electron microscopy (SEM) and evaluated by three masked observers.Prior to cutting, CTs did not differ significantly between OCT or USP measurements, with a high correlation between the two modalities (r(2)= 0.94, p 0.0001). One hour after preparation the anterior lamella showed a significantly higher dissection depth with the CBm (429.4 ± 21.8 µm) than the SLc (311.7 ± 54.8 µm, p = 0.0006), with the variance of the SLc system showing a trend towards higher values (p = 0.07). Anterior and posterior lamellae swelled significantly in the subsequent culture period. Both groups showed a significant ECL 1 h after preparation (p 0.0001) with no significant difference between the systems (1 h: p = 0.44; CBm: - 9.4%, SLc: -11.7%), which stabilized over 144 h (144 h CBm: -13.9%, 144 h SLc: -10.3%). LSR did not differ significantly between both systems (p = 0.60).The SLc system agrees more with the designated cutting depth than the CBm. The dissection produced a comparable LSR and a ∼10% ECL independently of the system. Further incubation of the prepared lamellae led to a swelling, but no further ECL.

BACKGROUND Metabolic changes of the human donor cornea during organ-culture are not at all reflected by the endothelium. Therefore metabolic investigations have become of increasing interest. It was the aim of this study to determine the correlation between glucose and lactate in storage medium and within the cornea itself and to find thereby an additional parameter for glucose metabolism during organ-culture. METHODS Glucose and lactate were examined in 166 organ-culture medium samples as well as in 106 human corneas by enzymatical optical methods. Investigations were carried out after 1, 7, 15, 21 and 28 days of organ-culture. RESULTS Glucose consumption was highest during the first two weeks of organ-culture. Glucose concentrations showed a good linear correlation between medium samples and the cornea (r = 0.923). The correlation coefficient for lactate was worse (r = 0.733). CONCLUSION Glucose and lactate levels in the organ-culture medium can be used as a marker for glucose metabolism in the cornea.

Background There are two well known systems to culture human corneas prior to transplantation. First, corneal storage at 4 degrees C especially in Optisol medium. Second, organ-culture at physiological temperatures in a modified minimal essential medium (MEM). In the cold storage system the number of endothelial cells after storage might be overestimated because the damaged cells are not able to leave the monolayer. It has been supposed that the lack in energy recruitment is the main reason for that, but has not been proven yet. It was the purpose of this study to describe the energy status of the human cornea after storage in both systems. Materials and methods 32 human corneas were investigated. They were stored for 7 days in Optisol, and for 7 days in MEM plus 1 day in MEM supplemented with 5% dextran 500 and 12 days in modified MEM plus 1 day in MEM supplemented with 5% dextran 500. The endothelial cell density (ECD) as well as the hydration were determined. Glucose, lactate, ATP, ADP and AMP were measured to reflect the energy status. Results Hydration was comparable in all three groups. ECD was slightly higher in Optisol stored corneas, although the amount of damaged cells was much higher. Optisol stored corneas showed a severe anaerobic situation, especially lacate concentrations were increased. In contrast ATP and ADP concentrations were twice as high in MEM than in Optisol stored corneas. Discussion The severe anaerobic situation in Optisol stored corneas leads to a lack in energy recruitment. This reduces the ability of cell function (mitosis) and the function of the monolayer (migration, elimination). Whether these changes are reversible after transplantation has to be determined in future.

Background Initial surgical treatment of severe eye burns is important for the long lasting healing period. To look closer at the efficacy of the early surgical treatment and the possible consequences for woundhealing, the surgical interventions were examined in an animal experiment. Materials and Methods The right eye of 20 rabbits each was burned with 1 n NaOH for 30 seconds followed by a surgical treatment 48 hours later. In the first study necrosectomy, tenonplasty, application of an artificial epithelium and blepharoplasty were performed. In a comparable study blepharoplasty was withdrawn and the fornices were prevented from cicatrization by mechanical treatment with blunt spatula. Antiinflammatory depotinjection of Volon A 40 was applicated additionally. After an interval of 4-18 weeks the eyes were examined histologically. Results A higher risk for infections could be observed in eyes which underwent blepharorhaphy. Furthermore proliferative processes and corneal ulcerations were predominant. In contrast to these findings the latter complications could be prevented due to the clinical inspection of the artificial epithelium and described mechanical irritation of the fornices in the second study. Discussion It could be shown that proliferative processes are major complications after severe burns of the eye. Nevertheless the intensity could be minimized by the consequent use of blunt spatula in combination with antiinflammatory therapy. Furthermore it could be demonstrated that the artificial epithelium is an effective tool providing good prognosis for subsequenty planned keratoplasty. To enable necessary postoperativ inspection blepharoplasty should be avoided.

The authors investigated 32 human corneal buttons of patients suffering from severe eye burns. The keratoplasties were performed in different periods after the burn and collected within five years. Grafts were followed-up until they failed because of ulceration or until rehabilitating keratoplasties were performed. Early (up to six months after the burn) and late (more than 12 months after the burn) obtained corneas showed different cellular reactions in the corneal stroma. Inflammatory cells such as granulocytes and lymphocytes decreased with increasing periods after the burn. More than 12 months after the burn, minor inflammatory cellular reactions but increasing scar formation could be found. Four out of 19 early-, two out of eight intermediate- (between six and 12 months after the burn) and one of the late performed keratoplasties failed and had to be replaced by new corneal grafts. Due to the conditions in the graft beds the explanted corneal grafts showed a cellular reaction in the stroma comparable to the previously explanted burnt corneae. Further complications occurred because of problems concerning the ocular surface. After preliminary therapeutical keratoplasties rehabilitating keratoplasties could be successfully performed in four cases between 19 and 39 months.

We investigated the kind of reactions that occur after injection of a PMMA lens powder into the back skin of rabbit. The lens powder was suspended in NaCl and incomplete Freund's adjuvant to reinforce the immunological reaction. The ELISA test was carried out to detect antibodies against the lens material as a whole and against the UV absorber Tinuvin in particular. We also performed histological and immunohistochemical examinations of the back skin. We did not detect antibodies against either the lens material or against Tinuvin. Histological examination showed a foreign-body or delayed allergic reaction against the lens material. Lymphocytes surrounding the PMMA were found to be mainly of the T-type, which supports the results of the ELISA test.

Following Crede's prophylaxis with silver-nitrate, the cornea of a newborn presented greyish-brown, lime-like plaques on the nasal part of the right eye. A paracentral ulcerating stromal opacification undermined these appositions, when the patient was admitted to the eye-clinic at Aachen. In the material taken in a lamellar keratectomy scanning electron microscopical examination was able to prove the existence of granules, previously described in light-microscopy. These granules measured 100 to 300 nm in diameter and were placed up to 110 microns deep into the corneal stroma of the specimen. An earlier chemical analysis of necrotic material showed no silver specific reaction. By means of EDX-Analysis these granules could be identified as silver-containing. This was once reassured by a newly developed modification of van-Kossa's-staining-method. The fact that the granular deposits contained mainly silver proves that the onset of a sodium-chloride-irrigation did not promote an intended therapeutic silver-chloride-precipitation and therefore had no effects on the silver-nitrate's penetration abilities. Injuries by silver-nitrate-solutions used for Crede's prophylaxis are seldom but still reported. The mechanism of injury in this case of a child, born by sectio remains unknown. Neither the use of an unusual silvernitrate solution, that was taken from a disposable ampoule (Mova-Nitrat) was reported, nor any corneal injury during sectio mentioned.(ABSTRACT TRUNCATED AT 250 WORDS)

Background In most clinical centers donor material can not be obtained in neccessary amounts. Therefore corneas from long-suffering donors have to be accepted, too. It was the aim of this study to demonstrate the influence of the cause of death on the endothelial cell density of fresh human corneas. Material and Methods The endothelial cell count of 81 donor corneas was determined after preparation of the corneo-scleral disc. For all donors the premortal history was evaluated concerning the cause of death and therapy. In this manner donors were divided into five groups: sudden death, carcinoma, septicemia, renal insufficiency and diabetes mellitus. Results There were no significant differences in endothelial cell count between these five groups. Even chemotherapy and radiatio of the donor had no influence on the cell density. Conclusion It may be concluded, that clear corneas have a sufficient endothelial cell density and that the cause of death has no influence on this parameter. Therefore also corneas from donors with long-standing diseases may be accepted for transplantation

Corneas are usually stored for a maximum of approximately 30 days in European cornea banks. Although attempts are being made to prolong culture periods, data on their success are extremely limited to date. The following study was carried out to describe the capacities and limits of the established system.Thirty-seven human corneas were stored foror = 12 weeks under standard eye bank conditions [modified minimal essential medium (MEM), 31 degrees C, closed system]. Twenty-one fresh human corneas served as control. Both the adenylate nucleotides and the glucose and lactate concentrations were measured in the tissue (all cellular layers) by using the bioluminescence technique. The endothelial-cell densities also were determined.Endothelial-cell densities decreased from 2,963.4 +/- 58.7 cells/mm2 (fresh) to 2,649 cell/mm2 after 4 weeks and to 2,087 cells/mm2 after 6 weeks. Storage for periods6 weeks led to total endothelial necrosis. Biochemical studies showed improving values during the first 4 weeks and acceptable conditions foror = 6 weeks.From these data, we conclude that long-term organ culture in a closed system is limited to approximately 6 weeks and thereby confirm the clinical results of Früh and Böhnke.

• Background: The presence of interleukins has been demonstrated in the cornea and other ocular tissues. Although pathogenic mechanisms are unknown, interleukins seem to be involved in inflammatory disorders of the cornea. The present study was undertaken to analyse concentrations of interleukin- Iβ (IL-1β) and interleukin-6 (IL-6) in human corneas with various clinical diagnoses. • Methods: Immediately after keratoplasty 127 explanted human corneas with various corneal diseases were snap frozen and cryosections were prepared for histological examination. Furthermore, the protein content was measured according to the method of Bradford and the concentration of IL-1β and IL-6 were determined using a specific immunosorbent test (ELISA). • Results: It was found that IL-1β and IL-6 level were clearly higher in corneas with ulcerations and distinct inflammatory signs. Lower levels of both interleukins were found in corneas with a weak expression of inflammatory signs. • Conclusions: Keratitis, keratoconus with inflammatory signs, and ulcerating processes showed higher interleukin levels than corneas with non-inflammatory disorders like scar formation, corneal dystrophy and keratoconus. The results could show that, depending on the clinical diagnosis, the inflammatory status of the cornea may be evaluated by the interleukin levels determined in the corneal tissue.

PURPOSE Tenon plasty has been used to reconstruct the conjunctival surface in severe burns in which ischemic sclera was exposed or undergoing ulceration. A modified impression cytology procedure was applied to investigate the conjunctival epithelium. The quality of the regenerated epithelium on the advanced Tenon sheets was assessed. METHODS The 63 conjunctival samples of eye-burn patients were investigated. Among these, 41 patients had very severe bums. Conjunctival samples were collected from 6 weeks after surgery to 5 years after the accident. They were compared with conjunctival epithelia obtained from 53 normal eyes of healthy volunteers. A 25-mm2 Biopore membrane (Millipore Catalogue PICM 01250) was placed on the bulbar conjunctiva surface in the lower temporal quadrant, at a distance of 3-5 mm from the limbus, till it was soaked with fluid. The ablated cell sheets were stained with periodic acid-Schiff (PAS). RESULTS In all cases, an intact conjunctival epithelium was observed. In healthy eyes, 2,338 epithelial cells/mm2 and 155 goblet cells/ mm2 were found. Eyes after a surgical reconstruction with Tenon plasty resulted only in 1,575 epithelial cells/mm2 and 72 goblet cells/mm2. The differences were highly significant. The ratio of epithelial to goblet cell counts revealed an increase of goblet cells during the postoperative period. CONCLUSION Conjunctival epithelium as well as goblet cell densities were reduced after heat, lime, alkali, and acid burns. However, after concrete burns, cell densities were increased. Tenon plasty provided the regeneration of the fully intact conjunctival epithelium. Goblet cells were present from 6 weeks after the surgery on; their number increased gradually. The stimulation of the goblet cell mucous secretion is discussed.