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C K Rostron

Publications and source records attributed to C K Rostron.

17 recordsLinked to original sources
PubMed2001

Deep lamellar keratoplasty with lyophilised tissue in the management of keratoconus.

AIMS: Data are presented on the use of deep lamellar keratoplasty (DLK) using lyophilised donor corneal tissue, in the management of patients with keratoconus (KC). METHOD: The results of DLK on 44 eyes (42 patients) are reported. The mean patient age was 29.8 years (range 10-56). Mean follow up was 25 months (range 6-100). In seven patients with mental handicap or severe mental illness, the collection of acuity and refractive data was limited. RESULTS: Perforation of Descemet's membrane (DM) occurred in nine cases (20%). A double anterior chamber formed in five cases, which resolved spontaneously in three patients. Persistent epithelial defects occurred in two cases, one of which necessitated replacement of the graft. The median postoperative uncorrected visual acuity was 6/36. The median corrected postoperative acuity was 6/9. Those with more than 1 year of follow up (n=25) had a significantly better acuity (p=0.015). This group achieved 6/12 or better in 80% (n=20) and 6/6 or better in 40% (n=10). The mean postoperative spherical error was +0.28 (SD 3.49) dioptres (D). The mean refractive cylinder was 3.85 (1.87) D. CONCLUSION: This detailed retrospective study of DLK for the treatment of patients with KC, with an average follow up of 2 years, highlights the advantages and disadvantages of this technique.

Adolescent↗
PubMed1998

HLA antigens in lyophilised corneal lenticules.

PURPOSE: To investigate the presence of Human Leukocyte Antigens (HLA) in organ cultured corneas, in lyophilised epikeratophakia lenticules prepared by dry state lathing, and in lenticules subjected to prolonged rehydration in Balanced Salt Solution (BSS). METHODS: Twelve lenticules and 3 organ cultured corneas were studied for the presence of HLA-ABC (class I), and HLA-DR, -DQ, and -DP (class II), antigens using the immunoperoxidase technique. RESULTS: HLA-ABC antigens were detected in all lenticules. HLA-DR antigen was also detected in low concentrations in 6 out of 12 lenticules. HLA-DQ and -DP antigens were generally absent. Incubation in BSS for 24 and 48 hours did not change the expression of antigens. CONCLUSIONS: HLA-class I, and to some degree HLA-class II antigens, are present in the stroma of both organ cultured corneas, and in lyophilised lenticules. Incubation in BSS for up to 48 hours did not reduce the expression of antigens.

Aged↗
PubMed1998

Corneal endothelial specular microscopy following deep lamellar keratoplasty with lyophilised tissue.

PURPOSE: To assess the corneal endothelial cell density following deep lamellar keratoplasty (DLK) carried out by air dissection and with the transplantation of lyophilised tissue. METHOD: Contact endothelial specular microscopy was carried out on a series of patients who had undergone DLK with a minimum of 1 year post-operative follow-up. RESULTS: Twenty eyes of 18 patients were examined at follow-up times ranging from 1 to 8 years post-operatively (mean 3 years). Indications for surgery were: keratoconus (n = 12), herpes simplex virus (HSV) keratitis (n = 1), herpes zoster ophthalmicus (HZO) keratitis (n = 1), lipid keratopathy (n = 2), lattice dystrophy (n = 1) and corneal scarring (n = 3). Overall, mean post-operative cell density was 2417 cells/mm2 (range 928-3656 cells/mm2). In eyes with pathological conditions not likely to have affected the endothelial cell density, such as keratoconus or lattice degeneration, the mean cell density was 2837 cells/mm2 (range 1030-3656 cells/mm2). CONCLUSIONS: In patients undergoing DLK for conditions such as keratoconus the post-operative cell density was at a normal level in the majority of cases. Cell loss through this surgical intervention thus appears generally to be small. The prospect for long-term survival of these grafts is good.

Adolescent↗
PubMed1998

A prospective controlled study of a 10/0 absorbable polyglactin suture for corneal incision phacoemulsification.

PURPOSE: To evaluate the performance of a 10/0 monofilament absorbable polyglactin suture for temporal 5.2 mm corneal incision phacoemulsification. METHODS: A prospective randomised controlled study of 49 patients undergoing phacoemulsification with a sutured temporal 5.2 mm corneal section was conducted to compare the refractive results and complications of a 10/0 monofilament absorbable polyglactin suture with 10/0 nylon. RESULTS: Thirty-eight patients completed the study. There was no significant difference in induced astigmatism between the two groups. All absorbable sutures were intact at 1 week. Six weeks post-operatively the absorbable suture was still intact in 1 (6%) patient, present but broken in 4 (24%) and completely absent in 12 (70%) patients. All polyglactin sutures had been completely absorbed by 12 weeks. Absorption of the polyglactin sutures was associated with mild localised corneal haze in 3(18%) cases (p = 0.055). One of the 18 patients (6%) in the polyglactin suture group presented with iris prolapse associated with knot failure 1 week post-operatively. There was no significant difference in foreign body symptoms between the two groups. CONCLUSIONS: 10/0 polyglactin sutures maintain adequate tensile strength during the immediate post-operative period for small incision surgery and are associated with minimal induction of astigmatism. Their subsequent absorption obviates the need for routine suture removal. Suture absorption is well tolerated although in some cases a mild degree of local tissue reaction raises concern about possible mechanisms of absorption. The risk of knot failure may be reduced by an alternative suture tying technique. 10/0 monofilament polyglactin is an attractive option when a suture is required during small incision cataract surgery.

Absorption↗
PubMed1998

Intraocular lens implants and risk of endophthalmitis.

AIM: To investigate the possible association between the use of three piece foldable silicone polypropylene (SPP) intraocular lenses (IOLs) and an increased risk of postoperative endophthalmitis. METHODS: A retrospective analysis was conducted of all cases of postoperative endophthalmitis following phacoemulsification surgery in a single unit over a 3 year period. The incidence of postoperative endophthalmitis in eyes with SPP IOLs was compared with the incidence in eyes with single piece polymethylmethacrylate (PMMA) IOLs. RESULTS: 772 cataract extractions by phacoemulsification were performed. One (0.16%) of the 622 patients with PMMA IOLs developed endophthalmitis. Excluding one patient who had aplastic anaemia, five (3.33%) of 150 patients with SPP IOLs developed endophthalmitis. The relative risk for postoperative endophthalmitis associated with the use of the SPP IOL compared with the PMMA IOL was 20.1 (p = 0.015). CONCLUSION: This study adds further evidence to the concept that SPP IOLs can be a significant risk factor in the development of postoperative endophthamitis.

Aged↗
PubMed1996

Fibrin glue: an alternative method of wound closure in glaucoma surgery.

PURPOSE AND METHODS: A commercially available tissue glue has been used to effect conjunctival wound closure after trabeculectomy. In four cases it was used in conjunction with sutures and in two cases alone to achieve watertight closure of the conjunctiva. A small transient leak was noted postoperatively in one case, and no case of flat anterior chamber occurred. RESULTS AND CONCLUSION: Intraocular pressure was controlled in all cases 3 months postoperatively. Tissue glue can be an effective method of achieving conjunctival wound closure in glaucoma surgery.

Conjunctiva↗
PubMed1992

Deep lamellar keratoplasty on air with lyophilised tissue.

Deep lamellar keratoplasty on air involves injecting air into the corneal stroma to expand it to several times its normal thickness. This method is designed to facilitate dissection of the deep stroma and reduce the risk of perforation of Descemet's membrane when carrying out deep lamellar keratoplasty. We have modified the technique by using prelathed freeze-dried donor tissue and report our results in a series of patients with corneal stromal scarring owing to a variety of corneal problems, namely, keratoconus, pterygium, and herpes zoster ophthalmicus. All patients achieved best corrected postoperative visual acuity of 6/12 or better without problems associated with graft failure or rejection. Histopathological examination of corneal tissue following air injection showed surgical emphysema within the cornea and separation of deep stromal fibres from the underlying Descemet's membrane.

Air↗
PubMed1989

The use of a biological adhesive to achieve sutureless epikeratophakia.

An adhesive made of concentrated human fibrinogen produced from samples of single donor blood by a simple cryoprecipitation method was tested for its ability to bond lamellar corneal buttons in vitro and found to have a bond strength of 140 gm/cm2. The adhesive was successfully used to attach experimental epikeratophakia grafts in a rabbit model. The results were similar to those reported from an earlier trial using a commercially available adhesive prepared from pooled multi-donor human plasma. This experimental trial of single-donor adhesive demonstrates the possibility of successful use of autologous fibrinogen adhesive in human epikeratophakia. Autologous adhesive would remove the possible threat of transmitted disease posed by multi-donor adhesive and avoid immune reactions to foreign proteins.

Animals↗
PubMed1988

Experimental epikeratophakia with biological adhesive.

Successful experimental epikeratophakia grafting was done with the use of a biological adhesive. The use of an adhesive eliminated the need for any suturing of the corneal lenticule to the host cornea, and this method reduced the length of the operative procedure to only one third of the time that is taken when sutures are used. Tisseel (Immuno AG, Vienna), a commercially available two-component adhesive system based on human fibrinogen, which is activated by thrombin, was used. The glue was used in combination with an antifibrinolytic agent. With alteration of the operative technique and lenticule design, 70% of glued epikeratophakia grafts in a rabbit model were retained, compared with a 50% success rate with grafts applied without the use of an adhesive.

Animals↗
PubMed1988

Epikeratophakia: clinical results and experimental development.

The clinical course and visual, refractive, and keratometric results of a consecutive series of epikeratophakia procedures carried out by the author are presented. Indications for the procedure included keratoconus and adult and paediatric aphakia. Follow up time ranged from two to fourteen months. The first five patients operated on received commercially obtained cryolathed lenticules. The final three cases received lenticules which were lathed by the author at room temperature using a recently developed technique.

Adult↗
PubMed1988

Experimental epikeratophakia using tissue lathed at room temperature.

This report presents for the first time the results of carrying out epikeratophakia with tissue lathed at room temperature. Using an experimental model of epikeratophakia in the rabbit, we evaluated tissue handling techniques for the preparation of donor lenticules. Details of the technique are described and the in-vivo and histopathological findings reported.

Animals↗
PubMedDate not supplied

Effects of air injection into the corneal stroma of man: an in vitro study.

BACKGROUND: Corneal stromal air injection has been described for assisting the deep dissection of the recipient corneal bed in lamellar grafting. The consistent finding of air entering the anterior chamber is considered an undesirable complication of the procedure. The route of air entry into the anterior chamber has not been investigated previously. METHODS: The route of air passage through the cornea was studied in 10 human cadaver eyes by direct viewing of the inner corneal surface with an operating microscope and by electron microscopy. RESULTS: Air entered the anterior chamber peripheral to Descemet's membrane in every case in the absence of pre-existing corneal pathology. The air expansion of the cornea occurred only along planes occupied by keratocytes and their cell processes and this expansion caused disruption of the keratocytes. CONCLUSIONS: Air injection into the cornea caused bubbles to enter the anterior chamber peripheral to Schwalbe's line, through the trabecular meshwork. The air produced cleavage of the collagen lamellae along those planes occupied by keratocytes and their cell processes since this provides a path of least resistance. Disruption of the keratocytes is a direct mechanical effect. Descemet's membrane and Bowman's layer act as effective barriers to air passage in the normal cornea.

Air↗
PubMedDate not supplied

Lamellar keratoplasty with lyophilized tissue for treatment of corneal scarring.

BACKGROUND: A pilot study was carried out in Pakistan to assess the feasibility of the use of lathed freeze-dried corneal tissue in the treatment of corneal scarring. METHOD: Six eyes underwent lamellar keratoplasty and were followed up for 18 months. RESULTS: Visual improvement was obtained in every eye. In one eye, the procedure was complicated by delayed epithelialization of the graft, but in the remaining five patients, the grafts epithelialized rapidly. CONCLUSIONS: The use of freeze-dried donor tissue simplifies storage and distribution of corneas and may offer the best hope of treatment in developing countries for patients with corneal scarring.

Adult↗