Classification of dry eye disease subtypes.

PURPOSE: The current subclassifications of dry eye disease (DED) are aqueous deficient (ADDE) and evaporative (EDE) forms, but there lacks consistency in the clinical characteristics used to define each of these. This study used clinical data to inform cut-off values for the subclassification of ADDE and EDE, to allow more consistent study of the epidemiology of both DED subtypes. METHODS: The study enrolled 261 residents from the UK, extracted from a cohort with demographics representing the population (mean 42.4 ± 18.7 years, 56 % females). The TFOS DEWS II diagnostic criteria were used to identify those with DED. Meibomian gland loss/drop-out (from meibography), lipid layer thickness (LLT - from interferometry graded on the Guillon-Keeler scale), and tear meniscus height (TMH - Keratograph 5M) along with tear evaporation (Delfin Vapometer) were used to characterise the subclassification. The Dry Eye Risk Factor Survey was used to assess risk factors associated with each DED subtype. RESULTS: Compared to individuals who were not diagnosed with DED, EDE was characterized by signs of meibomian gland loss of > 28 %, LLT grade < 3 and tear evaporation > 46 g/m2/h. In contrast, ADDE was best characterized by a reduced TMH < 0.2 mm. Based on these criteria, the prevalence of ADDE was 6.2 %, EDE was 64.2 %, and 11.1 % exhibited features of both ADDE and EDE, with 18.5 % unclassified despite having a DED diagnosis. Contact lens wear and computer use were risk factors for ADDE (p < 0.05), whereas age was a positive risk factor for EDE (p < 0.01). Meibomian gland loss (occurring in 27.9 %) was the most commonly observed sign in EDE. CONCLUSIONS: Data driven-classification of DED confirms that the evaporative form is most prevalent and identified that in a generalisable UK population, ADDE alone occurs only in approximately 1 in 16 cases of DED.

The epidemiology of dry eye disease in the UK: The Aston dry eye study.

PURPOSE: Cross-sectional studies on dry eye disease (DED) have relied on different diagnoses hindering conclusions about the disease epidemiology. This study offers an insight into DED epidemiology in the UK using prior and recent diagnostic recommendations. METHODS: Study participants comprised 282 volunteers from Birmingham, UK (median 40 years, range 18-88 years, 56% females). DED was defined by the Tear Film Ocular Surface Dry Eye Workshop II (TFOS DEWS II) criteria, based on a positive symptom score with the Dry Eye Questionnaire (DEQ-5) and Ocular Surface Disease Index (OSDI), and one of the following homeostasis markers: non-invasive tear break-up time of < 10 s (Oculus Keratograph 5M); the highest osmolarity value of ≥ 308 mOsm/L among eyes or an interocular osmolarity difference of > 8 mOsm/L (TearLab Osmolarity System); or > 5 corneal spots, >9 conjunctival spots or lower/upper lid-wiper-epitheliopathy staining of ≥ 2 mm length and ≥ 25% width (Oculus Keratograph 5 M). In addition, the Women's Health Study (WHS) criteria, based on symptoms or a prior dry eye diagnosis, was assessed. DED risk factors were gathered using a self-administered questionnaire. RESULTS: DED prevalence by the TFOS DEWS II criteria was 32.1% (95% confidence interval 25.5-37.7% and 29.5% (95% confidence interval 24.4-35.1% by the WHS criteria. Female sex, systemic and/or ocular health conditions, short sleep duration and prolonged outdoor leisure time spent were significant DED risk factors (p ≤ 0.05). CONCLUSIONS: Approximately one-third of the adult UK population have DED, aligning with the prevalence reported in multiple counties globally. Female sex, systemic/ocular health conditions, short sleep duration and prolonged outdoor leisure time are positive predictors of DED.

Therapeutic benefits of blinking exercises in dry eye disease.

PURPOSE: Dry eye disease (DED) is an important public health concern given its increasing prevalence and impact on patient quality of life. Blinking frequency and completeness are reduced during digital screen exposure, compromising meibum secretion and distribution, causing tear film instability and leading to DED. This study evaluated the effects of blinking exercises on blink pattern and clinical signs and symptoms of DED. METHODS: Fifty-four participants with dry eye symptoms received instructions to perform a ten-second cycle of blinking exercises every 20 min during waking hours for four weeks. Symptoms were assessed using the 5-item Dry Eye Questionnaire (DEQ-5) and Ocular Surface Disease Index (OSDI); blinking patterns measured with the TearScience LipiView II; and tear film and ocular surface parameters assessed with the Oculus Keratograph 5M. Measures at baseline and on day 28 were compared. RESULTS: Forty-one participants completed the study, reporting an average of 25.6 daily blinking exercise cycles. Improvements were noted in DEQ-5 (from 11 ± 4 to 7 ± 3; p < 0.001), OSDI (36 ± 18 to 22 ± 17; p < 0.001), non-invasive tear film breakup time (6.5 ± 2.4 to 8.1 ± 4.8 s; p < 0.04), the proportion of incomplete blinks (54 ± 36 to 34 ± 29 %; p < 0.001), but not in tear meniscus height or tear film lipid layer thickness. CONCLUSION: Blinking exercises can modify poor blinking patterns and improve dry eye symptomology, with modest changes in objective measures of tear film quality. Incorporating such routines into clinical care recommendations may improve blinking habits and help protect against the impact of digital device use on tear film quality and DED onset and evolution.

Spectrum and Sensitivity of Bacterial Keratitis Isolates in Auckland.

Background. The bacteria isolated from severe cases of keratitis and their antibiotic sensitivity are recognised to vary geographically and over time. Objectives. To identify the most commonly isolated bacteria in keratitis cases admitted over a 24-month period to a public hospital in Auckland, New Zealand, and to investigate in vitro sensitivity to antibiotics. Methods. Hospital admissions for culture-proven bacterial keratitis between January 2013 and December 2014 were identified. Laboratory records of 89 culture positive cases were retrospectively reviewed and antibiotic sensitivity patterns compared with previous studies from other NZ centres. Results. From 126 positive cultures, 35 species were identified. Staphylococcus was identified to be the most common isolate (38.2%), followed by Pseudomonas (21.3%). Over the last decade, infection due to Pseudomonas species, in the same setting, has increased (p ≤ 0.05). Aminoglycosides, cefazolin, ceftazidime, erythromycin, tetracycline, and doxycycline were 100% effective against tested isolates in vitro. Amoxicillin (41.6%), cefuroxime (33.3%), and chloramphenicol (94.7%) showed reduced efficacy against Gram-negative bacteria, whereas penicillin (51%) and ciprofloxacin (98.8%) showed reduced efficacy against Gram-positive bacteria. Conclusions. Despite a shift in the spectrum of bacterial keratitis isolates, antibiotic sensitivity patterns have generally remained stable and show comparability to results within the last decade from NZ centres.

Immunity of cholera in man: relative role of antibacterial versus antitoxic immunity.

Purified cholera toxoid is antigenic when given enterally and orally. Purified toxoid fails to provide protection against experimental challenge. Clinical cholera confers formidable protection against homologous or heterologous rechallenge. Failure to culture vibrios from intestinal fluid or stool of re-challenge volunteers suggests that the predominant immune mechanism is antibacterial rather than antitoxic.

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.

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.

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.

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.

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.

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.

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.

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.