Derek M. Tole

Reliability of impression cytology for the diagnosis of ocular surface squamous neoplasia employing the Biopore membrane

AIM To evaluate the accuracy of impression cytology employing a Biopore membrane device in the diagnosis of ocular surface squamous neoplasia (OSSN). METHODS The histology of patients undergoing excision biopsy for the suspected diagnosis of OSSN over a 20 month period was compared with the reported cytology of impression cytology specimens obtained preoperatively using the Biopore membrane device. RESULTS 25 excision biopsies were performed for suspected OSSN. There was accurate correlation in 20 out of the 25 cases (80%). In three cases (12%), there was poor correlation in that only a few dysplastic cells and hyperkeratosis were noted on cytology, whereas histology showed keratinising dysplasia in two cases and a moderately differentiated keratinising squamous cell carcinoma in the third. There were two cases (8%) of non-correlation—one keratinising dysplasia on histology, but anucleate keratin, squamous metaplasia, and rare atypical cells on cytology, and another case with very mild focal dysplasia on histology but squamous metaplasia on cytology. Review of the cytology showed that dysplastic cells were either rare or absent from the cytology specimens in these two cases; it was felt that these represented sampling problems rather than true false negatives. There were no false positives on cytology. Final diagnosis on histology was squamous cell carcinoma in one; carcinoma in situ in two; keratinising dysplasia in 15, non-keratinising dysplasia in seven. CONCLUSION Impression cytology employing the Biopore membrane accurately predicts the histological diagnosis of OSSN. The presence of hyperkeratosis, inflammatory cells with only a few dysplastic cells, may indicate high grade keratinising dysplasia or squamous cell carcinoma. The method is both rapid and easy to perform in routine clinical practice. These findings suggest that there may be a role for its use in the initial assessment and follow up of patients with suspected OSSN.

Amniotic membrane grafting in the surgical management of primary pterygium

Background: To evaluate the efficacy of amniotic membrane transplantation in primary pterygium surgery.

The suitability of corneas stored by organ culture for penetrating keratoplasty and influence of donor and recipient factors on 5-year graft survival.

PURPOSE To determine the impact of donor factors on the suitability of corneas stored by organ culture for penetrating keratoplasty (PK) and the influence of donor and recipient factors on 5-year survival of first PK. METHODS Logistic regression analyses were carried out to determine the influence of donor factors on, respectively, the risk of microbial contamination during organ culture, the suitability of corneas for PK (endothelial cell density ≥ 2200 cells/mm(2)), and the quality of corneas (endothelial cell density ≥ 2500 cells/mm(2)). Only one cornea, randomly selected, from each donor was included in these analyses. A Cox regression analysis was used to determine the influence of donor and recipient factors on 5-year PK survival. RESULTS Risk of contamination (n = 8317): Causes of donor death including infection, respiratory disease, and cancer all increased the risk of contamination during organ culture (P < 0.0001). Suitability for PK and endothelial quality (n = 7107): Donor age (P < 0.0001) and storage time in organ culture (P < 0.0001) were the principal factors affecting suitability and quality. Death to enucleation and enucleation to processing times had little influence. Corneas from organ donors were more likely to be suitable for PK (P = 0.0003). Five-year graft survival (n = 3014): Graft survival was dominated by the indication for PK (P < 0.0001). Allograft rejection was also a major risk factor for failure (P < 0.0001). The only donor factor affecting survival was sex (P = 0.008). CONCLUSIONS Donor age and storage time but not postmortem times influenced the suitability of corneas for PK. The indication for PK and other recipient factors were the main predictors of graft failure.

The use of rituximab in refractory mucous membrane pemphigoid with severe ocular involvement.

Mucous membrane pemphigoid (MMP) with ocular involvement is part of a spectrum of autoimmune disease, associated with chronic inflammatory changes and mucous membrane blistering. A 37-year-old gentleman presented to our clinic with a 3-month history of sore red eyes, treated with topical chloramphenicol for presumed bacterial conjunctivitis. During the preceding 3 months, he reported mouth and penile ulcers, dysphagia, hoarseness and blistering of plantar aspect of his right foot. Examination revealed …

Systemic tacrolimus in the treatment of severe atopic keratoconjunctivitis.

Purpose: Severe atopic keratoconjunctivitis (AKC) forms part of the spectrum of allergic eye disease and is often refractory to conventional topical treatment. Topical cyclosporin A and tacrolimus have been shown to reduce immunologic activation, symptoms, and signs of patients suffering from AKC, but there are no reports on safety and efficacy of systemic tacrolimus for this condition. Methods: We report on a retrospective study of 3 patients with severe AKC, where the disease did not respond to conventional therapy, and they were therefore treated with low-dose systemic tacrolimus for at least 1 year as an adjunct to their existing treatment. Results: There was a good clinical response in all patients to low-dose systemic tacrolimus, with a low incidence of side effects and no relapse of symptoms after discontinuation of treatment. Conclusion: Low-dose systemic tacrolimus is a safe and effective treatment of some patients with severe AKC, which is refractory to conventional treatment. Such patients need careful monitoring for side effects, and the long-term benefits need to be assessed as part of a clinical trial.

Electrolysis-needle cauterization of corneal vessels in patients with lipid keratopathy.

Purpose: To describe a case of infectious scleritis caused by methicillin-resistant Staphylococcus aureus (MRSA) after pars plana vitrectomy despite treatment with topical fourth-generation fluoroquinolones. Methods: Single interventional case report. Results: A 72-year-old man presented with scleral thinning and subconjunctival abscess 1 month after pars plana vitrectomy. Microbiological studies including cultures and antibiotic sensitivity were performed. Culture of the scleral abscess showed growth of MRSA resistant to fourth-generation fluoroquinolones and sensitive to vancomycin and erythromycin. Treatment with a combination of topical vancomycin and systemic erythromycin for 6 weeks resolved the infectious scleritis. Conclusions: MRSA can be a cause of infectious scleritis after ocular surgery without a clear source despite surgical prophylaxis with topical fourth-generation fluoroquinolones.

Outcomes of Same-Sizing versus Oversizing Donor Trephines in Keratoconic Patients Undergoing First Penetrating Keratoplasty

PURPOSE To investigate whether use of same-size donor and recipient trephines reduced myopia after penetrating keratoplasty for keratoconus. DESIGN Retrospective cohort study. PARTICIPANTS Eight hundred seventy-eight first grafts for keratoconus were reported to UK Transplant between April 1999 and December 2003. There were 234 and 644 grafts in the same-size and oversize donor trephine groups, respectively. At 1 year, mean spherical equivalent (SE) data were available for 116 eyes (50%) and 295 eyes (46%) in the same-size and oversize groups. At 2 years, mean SE data were available for 64 eyes (27%) and 148 eyes (23%) in the same-size and oversize groups. METHODS Logistic regression and univariate analysis of follow-up data submitted to UK Transplant. MAIN OUTCOME MEASURES At 1 and 2 years postoperatively, mean SE, magnitude of the cylindrical component of the refraction, postoperative uncorrected visual acuity (VA), postoperative best-corrected VA, and postoperative complications were recorded. RESULTS The mean SEs for the same-size and oversize donor trephine groups, respectively, were -1.45 diopters (D) and -1.41 D at 1 year (P = 0.6) and -1.74 D and -2.19 D at 2 years postoperatively (P = 0.3). Although there were no differences in graft survival between the groups at 1 and 2 years, there was a higher incidence of postoperative wound leaks in the same-size group (P = 0.03). CONCLUSION Use of same-size donor and recipient trephines did not reduce myopia and was associated with an increased risk of postoperative complications.

Long term topical steroid treatment after penetrating keratoplasty in patients with pseudophakic bullous keratopathy

PURPOSE To assess the use of long-term topical corticosteroid treatment in patients with pseudophakic bullous keratopathy (PBK) after penetrating keratoplasty (PK). DESIGN Retrospective cohort study. PARTICIPANTS This study considered patients with PBK undergoing an initial PK procedure for visual reasons in the United Kingdom between April 1999 and March 2004. There were 1274 initial PK procedures for PBK reported to United Kingdom Transplant in this period, of which 1184 (91%) were grafted for visual reasons. Of these 1184 grafts, follow-up was reported in 1033 instances (87%). METHODS A Cox regression model was used to investigate the combined effects of all preoperative factors (recipient age, human leukocyte antigen [HLA] matching, trephine size, deep stromal vascularization, surgeon activity) on graft failure. The model was fitted using all preoperative factors first, and subsequently, factors associated with corticosteroid and other medications were included. MAIN OUTCOME MEASURES Graft survival. RESULTS Three-year survival of grafts for PBK was 65% (95% confidence interval [CI], 59%-70%). Topical corticosteroids were still being used beyond 18 months after surgery in 378 (37%) of the 1033 corneal grafts included in this study. The grafts of patients not currently receiving steroids were 1.5 times as likely to fail (hazard ratio [HR], 1.5; 95% CI, 1.0-2.2; P<0.03). Lack of HLA matching (P = 0.006), trephine size <or=7.50 mm and >or=8.00 mm (P = 0.03), recipient age younger than 65 years (P = 0.003), and corneal vascularization (P = 0.04) all increased the risk of graft failure. CONCLUSIONS The use of long-term postoperative corticosteroids improved graft survival after PK for PBK. Barring patient contraindications for long-term topical corticosteroid use, clinicians should consider maintaining patients with PBK on long-term postoperative corticosteroid maintenance.

Ultrastructural evaluation of explanted opacified Hydroview (H60M) intraocular lenses

Aim: To describe the ultrastructural appearance of explanted opacified Hydroview H60M intraocular lenses. Methods: 14 explanted lenses were examined by scanning electron microscopy, and their appearance compared with a non-implanted H60M lens from the same time period. Wavelength-dispersive x ray spectroscopy (WDX) was performed on two opacified lenses. Results: Subsurface deposits were seen in all explanted opacified lenses. These deposits broke only onto the surface of more densely opacified lenses. WDX confirmed that the deposits contained both calcium and phosphorous, consistent with their being calcium apatite. Conclusion: These findings challenge the widely accepted opinion that H60M intraocular lens opacification begins on the surface of the optic.

Intraocular lens opacification after descemet stripping automated endothelial keratoplasty.

Purpose: Intraocular lens (IOL) opacification is a rare but serious complication that may necessitate its exchange. The use of intraocular gases is a known precipitant. Descemet stripping endothelial keratoplasty (DSAEK) involves injecting air into the anterior chamber. IOL opacification has been described after this procedure; however its incidence is currently unknown. Methods: A retrospective review of case notes from a single center of all patients undergoing DSAEK, who were either already pseudophakic or had simultaneous cataract surgery. Cases with IOL opacification were analyzed, and any risk factors were identified. Results: One hundred sixty-eight DSAEK were performed on 154 eyes of 137 patients. Fifty-four cases had simultaneous cataract surgery with implantation of an IOL. Fifteen (9.7%) eyes developed IOL opacification. This had a distinctive pattern, being limited to the anterior lens surface, in the pupillary zone. Median time interval from keratoplasty to the first observation of IOL opacification was 17 months (range, 4–34 months). The only statistically significant risk factor was rebubbling of detached endothelial grafts. Rebubbling was performed in 62.5% (10/15) of cases with IOL opacification, compared with 23% (32/139) with no opacification (P = 0.0009). Conclusions: This is the first study to report the incidence of IOL opacification after undergoing DSAEK. Although the mechanism is unknown, multiple injections of air into the anterior chamber statistically increase the risk of IOL opacification.