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Critical to the success of human corneal transplants is prevention of corneal endothelial rejection, yet little is known about the endothelial infiltrate. To examine the endothelium, a method for removal and processing this layer as a flat sheet was used and the infiltrate was compared with stroma and epithelium. LEW or PVG strain rat corneas were transplanted to PVG strain recipients. Clinical changes after transplantation were monitored by slit lamp and animals sacrificed at a range of time points during rejection. Clinically defined rejection, accompanied by an epithelial rejection line and endothelial cell infiltration, occurred between days 10 and 15. There was some infiltration of leukocytes in the stroma of isografts at these time points, but significantly more in allografts (p

An improved method of removing rat corneal endothelial sheets for study of endothelial pathology is described. The method was validated by examining morphological changes and changes in expression of major histocompatibility complex (MHC) and intercellular adhesion molecule (ICAM)-1 on endothelium undergoing immunological rejection. PVG strain rats received LEW strain corneal transplants or corneal isografts. Just prior to and during graft rejection, animals were killed, together with a group of untreated animals. The corneal stroma was injected with dispase or PBS, the cornea was carefully removed, fixed in acetone and the endothelium was gently peeled off and flattened on to a glass slide. Morphological changes, together with MHC class I, class II and ICAM-1 expression were visualised by immuno-histochemical staining and quantified by image analysis. Near complete endothelial sheets were obtained by this method. Because of the thin cell layer, there was minimal background staining, permitting rejection-associated changes to be clearly seen. MHC class I expression on normal endothelium was low and not significantly increased on endothelial cells of allografts at the time of rejection compared with controls (P = 0.1). MHC class II and ICAM-1 were induced de novo, expression being significantly higher on allografts than on isografts (P = 0.004 for MHC class II and P = 0.01 for ICAM-1). MHC class I and II and ICAM-1 were expressed on many infiltrating cells. Thus, this preparation method permits clear identification of the distribution and morphology of infiltrating cells and other mediators of the immune response in the entire donor endothelium. It confirms that MHC class I expression is low during rejection, while MHC class II and ICAM-I are induced de novo and strongly expressed.

Objective To compare postoperative astigmatism induced by two different suturing techniques in penetrating keratoplasty (PKP). Design A monocenter, prospective, randomized clinical trial with a longitudinal 1-year follow-up. Participants A total of 95 eyes undergoing PKP were randomized into 2 groups. Of these, 51 eyes were allocated to the combined interrupted and continuous suturing group (ICS) and 44 eyes to the single continuous adjustable suturing (SCAS) group. Intervention In the ICS group, suturing was with a combination of 12 interrupted 10-0 nylon and 1 continuous 11-0 nylon sutures. Eyes in the SCAS group had been sutured with a single running 24-bite 10-0 nylon. Selective suture removal started no earlier than 10 weeks after surgery; suture adjustment could start as soon as possible after surgery. Main outcome measures Astigmatism was measured by topography, keratometry, and refraction at 3-, 6-, 9-, and 12-month postoperative intervals. Results The difference in mean time of suture manipulation between groups was significant ( P = 0.0001), with the SCAS starting earlier. A significant decrease in astigmatism occurred by either interrupted suture removal (6.69 ± 3.11 diopter [D] before to 4.76 ± 2.99 D after, P = 0.0002) or suture adjustment (7.18 ± 3.12 D before to 4.46 ± 3.24 D after, P = 0.0001). However, the net astigmatic reduction in the SCAS group was not significantly greater ( P = 0.250) than in the ICS group. Vector change was 7.40 ± 4.17 D and 6.28 ± 4.14 D for SCAS and ICS, respectively ( P = 0.13). At no interval (3, 6, 9, or 12 months) was there significant difference in astigmatism between the two groups. Refractive astigmatism (cyl, D) at 1 year was 2.66 ± 1.70 for the ICS and 3.12 ± 2.62 for the SCAS, but there was no significant treatment effect ( P = 0.945). Furthermore, 66% of the ICS eyes and 58% of the SCAS eyes ( P = 0.295) were within the astigmatic target of the study ( Conclusions Postkeratoplasty astigmatism can be decreased similarly with either adjustment of a single running suture or selective removal of interrupted sutures. No advantage of the SCAS over ICS in terms of fewer manipulations or less astigmatism was seen as suggested previously.

Objective To assess the effectiveness of computerized videokeratography (CVK) in refining the surgical design and in improving predictability of surgical correction of postkeratoplasty astigmatism. Design A prospective, controlled, randomized, clinical trial. Participants A total of 31 postkeratoplasty eyes, divided into 2 groups (group A, 16 eyes; group B, 15 eyes), with more than 4 diopters (D) of disabling astigmatism were studied. Intervention All eyes were treated with combination of arcuate relaxing incisions and compression sutures. The surgical plan in group A was based on topographic information, whereas in the control group B, the surgical plan was based on information obtained by refraction and keratometry alone. Main outcome measures Change in the surgical plan induced by the CVK information, astigmatism, topographic patterns, and factors associated with outcome were measured. Results In all 16 cases of group A, the use of CVK changed some aspect of the surgical plan. At 12 months after surgery, both groups showed a significant net reduction ( P = 0.001) of baseline astigmatism. However, the reduction (47% and 41% for groups A and B, respectively) did not differ significantly between the two groups. The topographic astigmatism at 12 months measured 4.24 ± 0.71 D in group A and 5.60 ± 0.51 D in group B ( P = 0.139). Significant differences between the two groups at 12 months were seen only for keratometric astigmatism (3.60 ± 0.81 D in group A vs. 5.77 ± 0.52 D in group B, P = 0.035) and refractive astigmatism (2.34 ± 0.37 D in group A vs. 4.88 ± 0.52 D in group B, P = 0.000). The mean vector surgical effect was 91% for group A and 70% for group B. Regular astigmatism patterns had a greater benefit from surgery than irregular patterns ( P = 0.008). Previous refractive surgery was associated with less-favorable outcome ( P = 0.045). Conclusions The current study indicates that the use of CVK provides a benefit compared to keratometry and refraction alone in the planning and outcome of surgical treatment for high postgraft astigmatism.

Purpose: Carbomer gel is a water-soluble polymeric resin that has been reported to maintain the tear film in contact with the eye for an extended period. The efficacy and safety of this new artificial tear were assessed. Methods: A multicenter, single-masked, randomized, placebo-controlled study was carried out on 123 patients with moderate-to-severe dry eyes. The placebo was a mannitol solution with benzalkonium chloride 0.008% as preservative. Patients were observed over an 8-week period, and subjective and objective changes analyzed, compared to a baseline of no therapy, after 1 to 7 days washout period from previous medication. Results: All primary subjective symptoms decreased significantly in the carbomer gel-treated group compared to the placebo group (i.e., dryness, discomfort, and foreign body sensation). The carbomer gel also significantly improved the rose bengal staining score relative to placebo. When data for the primary subjective efficacy variables were stratified for disease severity, there was a statistically significant improvement from baseline by day 10 for severely affected patients and from day 42 for patients with moderate disease. Secondary subjective symptoms that improved significantly in the tear gel group compared to placebo were photophobia, erythema, tear breakup time, blurry-filmy, drysandy sensation, and physician impression. However, no significant improvements in the secondary subjective symptoms of tearing, itching, scaling, conjunctival discharge, palpebral conjunctival redness, bulbar conjunctival redness, conjunctival luster, relief of discomfort, ease of use, and overall acceptability were found in either group over the baseline score. In addition, neither carbomer gel nor placebo improved the baseline fluorescein staining score or the Schirmer test score. Two patients suffered local allergic reactions to the carbomer gel or its preservative, which settled on withdrawal of the medication. Conclusions: Carbomer gel was more efficacious than was placebo in improving a number of subjective and objective symptoms of moderate-to-severe dry eye syndrome. The results of this study indicate that carbomer gel was as safe as was the placebo.

Purpose: To quantify clinical and operative factors that influence corneal graft outcome. Methods: A multifactorial analysis was done on 2242 corneal grafts registered by the United Kingdom Transplant Service from July 1987, to June 1991. Results: There was an increased risk of graft failure in patients with preoperative diffuse and other noncentral stromal edema, less-common eye diseases, small trephine size, difference in donor and recipient sizes greater than 0.25 mm, and use of mixed continuous and interrupted sutures. Visual acuity 3 months after surgery was poorer in patients who had glaucoma and low visual acuity preoperatively, small trephine size, and combined vitreous surgery. Use of interrupted sutures resulted in higher astigmatism at 3 months. Conclusions: After allowing for the effects of recipient factors, surgical factors significantly affected corneal graft outcome. No factors that showed significant benefits for graft survival also adversely affected visual performance. Details of medical history, clinical condition, and surgical method failed to predict more than a small proportion of observed variability in visual performance of functioning grafts.

Following inoculation of the mouse cornea with herpes simplex virus type 1 (HSV-1), the spread of virus was investigated and the types of immune cell infiltrating the trigeminal ganglion (TG) were identified in low temperature paraffin wax sections. Virus antigen was first found on day 3 and was absent after day 14. Early presentation of antigen to T cells may occur since increased expression of major histocompatibility complex (MHC) class II antigens, including de novo expression on satellite and Schwann cells, was detected in foci of such antigen on day 3. A second large peak of such expression was detected on day 10 together with increasing numbers of B and T cells. Large numbers of these lymphocytes and extensive expression of MHC class II were seen in the TG well into the phase of virus latency; the significance of this is discussed.

Purpose: The Corneal Transplant Follow-up Study has followed 2385 corneal transplants performed in the United Kingdom and the Republic of Ireland for up to 450 days to quantify factors influencing corneal graft survival and visual outcome 3 and 12 months postoperatively. Methods: Multifactorial analyses of grafts registered by United Kingdom Transplant Support Service from July 1987 to June 1990 were used. Corrected visual acuity of functioning grafts was assessed at 3 and 12 months. Results: Of 2385 corneal transplants followed, 214 failures were observed: graft survival was 95% at 3 months and 89% at 1 year. Similar factors affected outcome at each time. Decreased risk of failure was associated with surgeons reporting most grafts, and increased risk was associated with regrafts, patients younger than 10 years of age, nonvisual reasons for grafting, endothelial failure, and deep vascularization. Visual outcome was worse in older patients and was associated with cosmetic reasons for grafting, superficial vascularization preoperatively, and secondary endothelial failure. Visual acuity was better when the other eye had been grafted previously, or when the diagnosis was keratoconus or stromal dystrophy. Conclusions: Primary endothelial failure was associated with high failure rates but good visual results when functioning. Most other factors had similar effects on both outcome measures. Improved outcome under highest-reporting surgeons was slight, and indicated possible differences in postoperative care.

Human and rabbit isolated eyes were compared, not in order to propose yet another test, but to explore the boundaries of the rabbit isolated cornea as a model for primary damage to human cornea. Changes in corneal thickness and in epithelial morphology were followed on recovery from cold-induced oedema and after exposure to the test chemicals. There was no statistical difference between control human and rabbit eyes in recovery from severe oedema. The effects of exposure to allyl alcohol, Arlagard E, NaOH (1 N), NaCl, sodium lauryl sulphate (2%) and Tween-20 were similar in human and rabbit eyes. Acetone, ethanol and glycerol had opposed-sign effects on corneal thickness in human and rabbit. From the small number of substances tested it can be concluded qualitatively that stored rabbit eyes behave in a manner similar to freshly isolated rabbit eyes, and that substances in which penetration depends on surface properties of the cornea may have species-specific effects.

A 14-month-old girl had inclusion conjunctivitis although there had been no signs or symptoms that required medical attention in her first year. By 2 1/2 years of age, the child had extensive pannus and corneal scarring that severely reduced vision. The infection was caused by a genital strain of Chlamydia trachomatis, TRIC type E, that was probably acquired at birth. Although genitally transmitted chlamydial strains normally cause a self-limiting inclusion conjunctivitis in areas where trachoma is not endemic, this case illustrates that they may occasionally cause severe trachoma. Possibly local idoxuridine (IDU) treatment (administered to this patient before the correct diagnosis was made) contributed to the severity of this infection.