Genomic DNA sequence comparison between two inbred soybean cyst nematode biotypes facilitated by massively parallel 454 micro-bead sequencing.

Heterodera glycines, the soybean cyst nematode (SCN), is a damaging agricultural pest that could be effectively managed if critical phenotypes, such as virulence and host range could be understood. While SCN is amenable to genetic analysis, lack of DNA sequence data prevents the use of such methods to study this pathogen. Fortunately, new methods of DNA sequencing that produced large amounts of data and permit whole genome comparative analyses have become available. In this study, 400 million bases of genomic DNA sequence were collected from two inbred biotypes of SCN using 454 micro-bead DNA sequencing. Comparisons to a BAC, sequenced by Sanger sequencing, showed that the micro-bead sequences could identify low and high copy number regions within the BAC. Potential single nucleotide polymorphisms (SNPs) between the two SCN biotypes were identified by comparing the two sets of sequences. Selected resequencing revealed that up to 84% of the SNPs were correct. We conclude that the quality of the micro-bead sequence data was sufficient for de novo SNP identification and should be applicable to organisms with similar genome sizes and complexities. The SNPs identified will be an important starting point in associating phenotypes with specific regions of the SCN genome.

The effects of corneal parameters on the assessment of endothelial cell density in the elderly eye.

BACKGROUND: The possible impact of corneal thickness, curvature, and size on the measurement of endothelial cell density (ECD) has largely been ignored in the normal eye. The aim of this study was to investigate the possible impact of the main corneal parameters on the analysis of ECD values at the central, superior, and temporal parts of the corneal surface. METHODS: All 75 participants (52 females, 23 males) were assessed as part of a pre-cataract surgery investigation. The mean age was 75.7 (SD 10.9) years. Confocal microscopy was used to measure ECD and the percentage of six sided cells at the central, superior, and temporal parts of the cornea. The Orbscan II topography system was used to measure corneal thickness, topography, and horizontal corneal diameter. RESULTS: The mean central ECD measured was 2488 (SD 301) cells/mm(2), compared with 2525 (SD 505) cells/mm(2) in the temporal cornea and 2639 (SD 398) cells/mm(2) in the superior cornea. The regional differences in ECD were not significant (p>0.14). The central ECD was significantly correlated to the central (mean 0.593 (SD 0.039) mm, p = 0.021) as well as the temporal (0.628 (SD 0.039) mm, p<0.001) and the superior corneal thickness (SD 0.644 (SD 0.048) mm, p = 0.018). The mean corneal curvature at the centre (7.7 (SD 0.34) mm, p = 0.002) as well as 3 and 5 mm from the apex was significantly related to ECD (p = 0.008 and p = 0.009, respectively). CONCLUSIONS: The study suggests that in an older population, lower ECD values would be expected in thinner and/or steeper corneas.

Comparison of corneal thickness measurements using ultrasound and Orbscan slit-scanning topography in normal and post-LASIK eyes.

PURPOSE: To compare corneal thickness measurements made by ultrasonic and slit-scanning techniques in normal eyes and in eyes after laser in situ keratomileusis (LASIK). SETTING: Corneal Diseases and Excimer Laser Research Unit, University of Dundee, Dundee, Scotland. METHODS: Central corneal thickness (CCT) was measured in 101 eyes of 59 normal subjects and in 30 eyes of 21 post-LASIK patients. Measurements were made with an Orbscan slit-scanning elevation topographer and immediately afterward with an ultrasound pachymeter. RESULTS: The difference in mean CCT between ultrasound (538.0 microm +/- 36.7 [SD]) and Orbscan (566.6 +/- 40.7 microm) pachymetry was statistically significant (P <.001) in the normal eyes; the Orbscan measurement was approximately 28 microm higher than that of the ultrasound pachymeter. The difference in mean CCT between the ultrasound and the slit-scanning techniques was also statistically significant in the post-LASIK eyes (mean values 475.3 +/- 50.3 microm and 461.9 +/- 74.2 microm, respectively; P <.0001). Differences in CCT in individual subjects were much more variable in the post-LASIK eyes than in the normal eyes. The Bland and Altman method for assessing clinical agreement between 2 instruments showed that in 95% of cases, the CCT measurements with both instruments would be within 65 microm in normal eyes and 150 microm in post-LASIK eyes. CONCLUSION: Central corneal thickness measurements were, on average, 28 microm higher with the Orbscan than with the ultrasound pachymeter in normal eyes and 13 microm lower in post-LASIK eyes. The degree of variability within each group indicated that these 2 techniques are not clinically comparable, precluding interchangeable use of their data in planning or assessing corneal surgery.

In vivo confocal microscopy of corneal epithelial ingrowth through a laser in situ keratomileusis flap buttonhole.

We report a case of epithelial ingrowth through a buttonhole 6 months after laser in situ keratomileusis. Elevation topography showed irregular astigmatism and an unreliable pachymetric map. In vivo confocal microscopy showed an epithelial basal cell mosaic with prominent borders and distinct nuclei. No corneal nerves were identified in any image. Cells in the anterior stroma possessed bright, reflective nuclei and appeared to form clusters. The interface between the stromal bed and the flap had formation of nests of fibrotic tissue and epithelial cells.

Safety and predictability of laser in situ keratomileusis enhancement by flap reelevation in high myopia.

PURPOSE: To evaluate the safety and predictability of laser in situ keratomileusis (LASIK) retreatment following primary procedures for high myopia and astigmatism. SETTING: Corneal Diseases and Excimer Laser Research Unit, Department of Ophthalmology, University of Dundee, Dundee, United Kingdom. METHODS: This prospective observational study of retreatment comprised a cohort of 109 eyes having primary LASIK for high myopia and astigmatism with a spherical equivalent (SE) of -9.70 diopters (D) +/- 4.06 (SD). Twenty-four eyes (22%) with an initial myopic SE of -9.83 +/- 3.50 D, a comparable subset of the entire group (P < .05), had retreatment for residual myopia (-3.02 +/- 2.17 D) to improve uncorrected visual acuity (UCVA) by reelevating the corneal flap and ablating the stromal bed. RESULTS: The mean follow-up after retreatment was 12.8 +/- 5.1 months (range 1.5 to 24 months; 19 eyes >/=6 months, 13 eyes > or = 12 months). The mean myopic SE was reduced to +0.53 +/- 0.62 D at 1 week, +0.05 +/- 0.50 D at 1 month, +0.30 +/- 0.50 D at 6 months, and +0.18 +/- 0.42 D at the latest follow-up, 12.8 months. At the latest review, 62% of eyes were within +/-0.50 D of emmetropia and 100% were within +/-1.00 D. The mean refraction did not alter statistically between 1 week and subsequent times. The mean UCVA improved from 6/30 prior to retreatment to 6/9 at the latest follow-up. Uncorrected visual acuity of 6/6 or better, 6/9 or better, and 6/12 or better was achieved by 33.0%, 75.0%, and 95.8% of eyes, respectively. No significant complications that led to a loss of best corrected visual acuity were encountered, although retreatment procedures were more uncomfortable than primary procedures and self-limiting; epithelial ingrowth that did not threaten vision was common, and 2 patients complained of nighttime visual symptoms. CONCLUSIONS: Retreatment of residual myopia by reelevating the flap was relatively safe and predictable, with a low risk of sight-threatening complications. However, longer term studies may be required to detect late complications.

An optometrist's personal perspective of aspects of refractive surgery.

The latter part of the last century has seen significant evolution in the area of refractive surgery, such that is has become a viable alternative to contact lenses, or spectacles, for an increasing number of patients. The developments of the principal techniques, in this ever-expanding field, are reviewed, and the increasing rôle of the optometrist in the pre-, intra- and post-operative management of the refractive surgery patient is described, based upon the author's personal experience within a non-profit, refractive surgery setting. In addition to highlighting pertinent features of the objective evaluation of patients, the importance of subjective assessment, pre- and postoperatively, is discussed, in terms of maximising post-surgery patient satisfaction. The scope for future research in this dynamic area is also considered.

The waiting game: natural history of a cataract waiting list in New Zealand.

AIMS: To identify the demographic and visual function of patients on the reserve waiting list for cataract surgery at a large public hospital within New Zealand and to determine the ultimate outcome of those on a priority-based, rationed, health-care waiting list. METHODS: Patients from a defined geographical population, placed on a reserve waiting list for possible cataract surgery, during the period January 1997 to March 2000, were invited to attend for further clinical assessment and asked to complete a visual assessment questionnaire. RESULTS: Of 193 patients in the pilot study group who had been on the reserve waiting list for a mean of 18.2 +/- 11.6 months (range 0.1-62.7 months), only 94 (49%) were deemed suitable for, and subsequently underwent, surgery in the public sector. Forty-nine (25%) had undergone surgery earlier, the majority of these (84%) in the private sector. A further 23 (12%) patients were deceased, four (2%) declined surgery and in six (3%) cataract surgery was no longer indicated. The remaining 11 (6%) patients could not be traced. Patients still awaiting surgery had a mean age of 77.2 years (range 48-95 years). Fifty-four were women. Vision had deteriorated by a mean of 0.05 LogMAR units, from Snellen equivalent 6/30 at listing to 6/36, over this time. CONCLUSIONS: Current methods of prioritization for cataract surgery are imperfect, as are the resources for performing adequate levels of cataract surgery. Analysis of a residual waiting list for cataract surgery highlights that the majority (51%) do not ultimately progress to cataract surgery in the public sector for a variety of reasons. During a mean waiting time of 1.5 years vision further deteriorates in this predominantly older population.

The Auckland Cataract Study: demographic, corneal topographic and ocular biometric parameters.

PURPOSE: To determine patient demographics and the ocular biometric parameters in patients presenting for cataract surgery within the public hospital system, in a defined New Zealand population. METHOD: Prospective study of 502 eyes of 488 consecutive patients undergoing cataract surgery. A clinical assessment, including refraction, keratometry (K), A-scan ultrasound and Orbscan II computerized topography was performed on each eye. RESULTS: The mean age of the group was 74.9 +/- 9.8 years (mean +/- SD) with a female predominance (62%). Ethnic origin included 72% European, 8% Maori, 10% Pacific Islander, 4% Asian, 3% Indian and 3% other ethnic origins. The mean Log MAR visual acuity of eyes prior to cataract surgery was 0.88 +/- 0.57 (approximately 6/48(-1)). Corneal topographic (keratometric) maps were classified into five groups: 34% round, 10% oval, 31% symmetrical bow tie, 12% asymmetrical bow tie and 13% irregular. The mean steepest K measurement was 44.1 +/- 1.7 D, the median keratometric astigmatism 0.89 D (range 0.0-6.5 D) and the steepest corneal meridian was horizontal in 50% and vertical in 43%. Seven per cent of corneas were spherical. Refraction revealed a mean sphere of 0.0 +/- 3.1 D and a mean cylinder of -1.2 (range 0.0-7.5 D). Refractive astigmatism was with-the-rule in 15%, against-the-rule in 50% and oblique in 15%, with 20% spherical. Axial length was a mean of 23.14 +/- 1.03 mm. CONCLUSION: Patients presenting for cataract surgery in this study were predominantly elderly, female, of European Caucasian ethnicity and exhibited relatively poor corrected visual acuity in the affected eye. Interestingly, 41% of eyes demonstrated bow-tie topographic patterns, largely exhibiting with-the-rule astigmatism. However, assessment by keratometry or refraction highlighted against-the-rule more frequently; this may have implications for combined cataract and astigmatic surgery. The mean axial length was slightly shorter than expected for a group of predominantly European ethnic origin, although the mean refractive error was emmetropic.

Laser in situ keratomileusis for ametropia after penetrating keratoplasty.

PURPOSE: To evaluate the efficacy of excimer laser in situ keratomileusis (LASIK) in the treatment of refractive errors after penetrating keratoplasty. METHODS: Eight eyes underwent LASIK after a mean 71 months (SD 60) following the initial penetrating keratoplasty. A full ophthalmic assessment was performed before LASIK and at 1 week, 1, 3, 6, and 12 months after surgery. Mean follow-up was 8.6 months (SD 3.2). RESULTS: No eyes lost any Snellen lines of best spectacle-corrected visual acuity at the latest follow-up. Mean reduction in spherical equivalent refraction was 91% from -6.79 D (SD 4.17) to -0.64 D (SD 1.92) and mean reduction of cylinder was 72% from -6.79 D (SD 3.28) to -1.93 D (SD 1.17) at 6 months. Mean surgically induced astigmatism was 5.50 D (SD 2.42) and the index of surgically induced astigmatism divided by the initial cylinder expressed as a percentage was 81%. Mean outcome indices were: correction index 0.87, index of success 0.31, and angle of error 0.95 degrees. Three eyes (43%) achieved a spherical equivalent refraction of +/-0.50 D and 4 eyes (57%) achieved a spherical equivalent refraction of +/-1.00 D of emmetropia. CONCLUSIONS: The efficacy of LASIK after penetrating keratoplasty was good compared to incisional or surface based excimer laser methods and has the advantage of reducing the myopic spherical equivalent refraction in addition to astigmatism, thus improving the uncorrected visual acuities.

Functional, psychological, and satisfaction outcomes of laser in situ keratomileusis for high myopia.

PURPOSE: To identify factors that motivate patients to seek laser in situ keratomileusis (LASIK) treatment for myopia and establish subjective levels of functional improvement and satisfaction across a range of indices after LASIK surgery. SETTING: The Corneal Diseases and Excimer Laser Research Unit, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland. METHODS: In this questionnaire-based, cross-sectional study, an anonymous 34-item questionnaire was forwarded to 50 consecutive patients in a prospective study who had had LASIK for high myopia by a single surgeon at a single center. The questionnaire used visual analog scales, anchored at each end by an adjectival descriptor. The mean preoperative myopia was -10.7 diopters +/- 4.4 (SD). Seventy-six percent of eyes (83% of patients) achieved post-LASIK uncorrected visual acuity (UCVA) of 6/12 or better; 1 eye lost 2 lines of corrected Snellen visual acuity. RESULTS: A 98% reply rate was achieved. The most common motivating factor for pursuing LASIK was to improve UCVA (88%); only 21% rated improved cosmesis as an important motive. Most patients (81% to 100%) reported functional improvement across the spectrum of visual tasks assessed, although 8.8% reported difficulty with nighttime driving. Ninety-six percent felt their UCVA was as good as anticipated, 97.9% were satisfied with the speed of visual improvement, 93.8% achieved the goals for which they had surgery, 97.9% reported an improved quality of life, and 97.9% were satisfied with the overall outcome of LASIK. CONCLUSIONS: Using an anonymous, wide-ranging questionnaire, high levels of functional improvement and satisfaction with the speed of visual recovery and outcome were reported by patients after LASIK for high myopia. Nighttime driving symptoms of variable severity were, however, noted by 8.8% of patients, despite high levels of satisfaction with other aspects of visual function.

Optic disc interpretation in glaucoma: is confidence misplaced?

A photographic questionnaire has been used to investigate whether or not clinicians have realistic expectations of their ability to distinguish optic discs associated with glaucomatous visual field loss from discs of healthy eyes. The questionnaire consisting of 30 non-stereoscopic fundus photographs from 15 patients was administered to 40 ophthalmologists of varying experience and 10 optometrists. Each group displayed large discrepancies between their expected and achieved scores suggesting that clinicians may overestimate their ability to recognize the glaucomatous optic disc. This could lead to diagnostic errors especially in cases where tonometric and visual field parameters are considered equivocal. An over-reliance on the cup/disc ratio appeared to be the most likely cause of error.

Gold-associated lymphadenopathy in a patient with rheumatoid arthritis. Histologic and scanning electron microscopic features.

The histologic features of adenopathy associated with intramuscular injections of gold sodium thiomalate in a woman with rheumatoid arthritis are presented. We believe that the light microscopic features of the above process are sufficiently distinctive that a diagnosis of gold-associated lymphadenopathy could be rendered. A review of the literature revealed no descriptions of the light microscopic appearance of gold in lymph nodes. In this case, the diagnosis of gold-associated lymphadenopathy was confirmed by scanning electron microscopic studies.

Secretory carcinoma of the breast in an adult. Correlation of aspiration cytology and histology on the biopsy specimen.

Needle aspiration was performed on the excisional biopsy specimen of a breast mass in a 63-year-old woman. The cytologic features in the aspirate included solid and papillary proliferations of tumor cells with abundant intracytoplasmic vacuolization and secretion. Histologic study of the lesion showed a secretory carcinoma. Although this is a rare breast neoplasm, especially in adults, the cellular features are characteristic and may permit a specific diagnosis on needle aspirates.

The adjuvant effect of pertussis endotoxin protein in modulating the immune response to cholera toxoid in mice.

Endotoxin protein represents a group of immunobiologically active p polypeptides which are associated with the lipopolysaccharide endotoxin in the outer membrane of Gram-negative bacteria. To study the adjuvant effect of endotoxin protein, CF-1 mice were immunized intraperitoneally with graded doses of glutaraldehyde-inactivated cholera toxoid with and without endotoxin protein prepared from Bordetella pertussis, Salmonella typhi or Vibrio cholerae. Immune responsiveness was assessed by measuring resistance to intravenous challenge with cholera enterotoxin and by serum antitoxin responses. The results showed that endotoxin protein from S. typhi can enhance the 50% protective dose (PD50) of cholera toxoid five to 12-fold, the endotoxin protein from V. cholerae enhances the PD50 six to seven fold at most, but the endotoxin protein from B. pertussis can enhance the PD50 some 27-fold. Furthermore, within the variability of both the mouse protection test and the rabbit intracutaneous assay of toxin induced vascular permeability, mouse serum neutralizing antitoxin levels correlated with the greater degree of resistance of the mice to the toxin challenge. The adjuvant effect also has been demonstrated by measuring the appearance of antitoxin specific plaque forming cells derived from mouse lymphocyte cultures. After seven days of culture in the presence of endotoxin protein and cholera toxoid, the number of plaque forming cells to cholera toxin coated sheep erythrocytes was enhanced some 28 times as compared to the cultures exposed to the cholera toxoid alone.

Cysts containing renal cell carcinoma in von Hippel-Lindau disease.

We report on a patient with von Hippel-Lindau disease. Exploration revealed 15 solid tumors and 18 cysts filled with clear fluid throughout both kidneys. All solid tumors consisted of clear cells consistent with renal cell carcinoma. All cysts were lined with similar clear cells. The solid tumors contained areas of clear cells surrounding small cystic spaces and the large cysts appeared to be an exaggeration of this phenomenon. There is a place for radical ablative surgery in patients with multiple renal cell carcinomas in von Hippel-Landau disease. Unroofing and gross examination of apparently simple cysts may not be adequate to rule out the presence of carcinoma in these patients.