Manual no-fold push-in DSAEK graft insertion technique.

PURPOSE: To describe the manual no-fold push-in technique for Descemet stripping automated endothelial keratoplasty (DSAEK) graft insertion and analyze postoperative endothelial cell loss. METHODS: Twenty consecutive patients underwent DSAEK surgery using the manual no-fold push-in technique. This insertion technique uses a 6-mm limbal wound, a Sheets glide, and a Sinskey hook without the need for an inserter or additional instrumentation. RESULTS: Three patients developed graft dislocation, requiring re-bubbling. No primary graft failures were encountered. With an average postoperative follow-up of 13.22 months (SD, 7.94; range, 2.23-26.87), average automated endothelial cell count was 2329.62 cells per mm (SD, 312.78; range, 1657-2928) and the average cell loss was 23.31% (SD, 11.33; range, 5.56-42.76). CONCLUSIONS: This technique uses standard instrumentation and is simple to perform. This series demonstrates that manual graft insertion techniques can be effectively used in DSAEK surgery and provide patients with excellent postoperative results.

Comparison of a monocular pupillometer and the pupillometry function of a binocular free-viewing autorefractor.

PURPOSE: To compare a binocular free-viewing autorefractor pupillometer (WAM 5500 Binocular Accommodation Instrument) and a monocular occlusion pupillometer (Neuroptics pupillometer). SETTING: Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA. DESIGN: Evaluation of diagnostic test or technology. METHODS: Normal subjects were tested under 1 lux and 7 lux ambient illumination with controlled distance fixation. The monocular occlusion pupillometer and free-viewing autorefractor pupillometer test order and eye test order were randomized. Devices were compared using Bland-Altman plots. Effects of eye test order and device test order were analyzed. The number of outliers (ie, difference ≥ 0.5 mm between devices) was tabulated. RESULTS: The mean device difference (monocular pupillometer minus binocular pupillometer) was +0.51 mm ± 0.36 (SD) (range -0.20 to +1.50 mm) in right eyes and +0.27 ± 0.31 mm (SD) (range -0.30 to +1.00 mm) in left eyes at 1 lux and +0.26 ± 0.28 mm (range -0.30 to +0.90 mm) and +0.21 ± 0.24 mm (range -0.80 to +0.40 mm), respectively, at 7 lux. The outlier frequency (N = 49) at 1 lux was 23 (47%) in right eyes and 7 (14%) in left eyes and at 7 lux, 11 (22%) and 10 (20%), respectively. At all age decades, the free-viewing autorefractor underestimated dark-adapted pupil diameter. Eye test order and device order did not cause unidirectional bias. CONCLUSIONS: The free-viewing pupillometer frequently disagreed with the monocular occlusion pupillometer by more than 0.5 mm. Testing the first eye with the monocular pupillometer did not induce sustained pupillary constriction that might bias results in the second eye.

Comparison of 2 monocular pupillometers and an autorefractor for measurement of the dark-adapted pupil diameter.

PURPOSE: To compare the performance of the Marco Nidek ARK-530A autorefractor pupillometer function and the Keeler PupilScan II pupillometer (study pupillometer) against the clinical standard NeurOptics PLR-200 pupillometer (standard pupillometer) for measurement of the dark-adapted pupil diameter. SETTING: Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA. DESIGN: Evaluation of diagnostic test or technology. METHODS: Subjects aged 20 to 60 years were dark-adapted for 2 minutes at 1 lux ambient illumination. Accommodation was controlled through distance fixation. The dark-adapted pupil diameter was measured with the standard pupillometer, then the study pupillometer, then the autorefractor. Results were compared using Bland-Altman graphs. RESULTS: The autorefractor underestimated the dark-adapted pupil diameter by a mean of 1.03 mm (range 0.0 to 2.3 mm). Thirty-four (85%) measurements were at least 0.5 mm smaller than the corresponding standard pupillometer values, and 16 (40%) were more than 1.0 mm smaller. Observer experience did not improve accuracy. The study pupillometer underestimated the dark-adapted pupil diameter by a mean of 0.31 mm (range 0.0 to 0.9 mm). Ten (25%) measurements were at least 0.5 mm smaller than the standard pupillometer values. Accuracy improved in the final 10 subjects (study pupillometer smaller; mean difference 0.16 mm; range 0.0 to 0.4 mm). CONCLUSIONS: The autorefractor pupillometry function had an unpredictable negative bias (variable underestimation of dark-adapted pupil diameter). The study pupillometer had a slight negative bias but required significant examiner skill and knowledge of normal pupil movement to obtain a valid result. Neither device was sufficiently accurate for confident surgical planning or clinical diagnosis. FINANCIAL DISCLOSURE: Neither author has a financial or proprietary interest in any material or method mentioned.

Dark-adapted pupil diameter as a function of age measured with the NeurOptics pupillometer.

PURPOSE: To measure the dark-adapted pupil diameter of normal research participants in their second through ninth decades of life using the NeurOptics pupillometer (Neuroptics Inc). METHODS: Individuals aged 18 to 80 years with no history of eye disease or injury, intraocular surgery, or use of systemic antihistamines or opiates were recruited. After 2 minutes of adaptation at 1 lux illumination, the right dark-adapted pupil diameter was measured using the NeurOptics pupillometer, with accommodation controlled by distance fixation. The NeurOptics pupillometer reported a mean dark-adapted pupil diameter and a standard deviation of the mean, which were analyzed as a function of age-decade. RESULTS: Two-hundred sixty-three individuals participated. For participants aged 18 to 19 years (n=6), the mean dark-adapted pupil diameter was 6.85 mm (range: 5.6 to 7.5 mm); 20 to 29 years (n=66), 7.33 mm (range: 5.7 to 8.8 mm); 30 to 39 years (n=50), 6.64 mm (range: 5.3 to 8.7 mm); 40 to 49 years (n=51), 6.15 mm (range: 4.5 to 8.2 mm); 50 to 59 years (n=50), 5.77 mm (range: 4.4 to 7.2 mm); 60 to 69 years (n=30), 5.58 mm (range: 3.5 to 7.5 mm); 70 to 79 years (n=6), 5.17 mm (range: 4.6 to 6.0 mm); and 80 years (n=4), 4.85 mm (range: 4.1 to 5.3 mm). These values were consistent with studies using infrared photography. The standard deviation was >0.1 mm in 10 (3.8%) participants, all of whom were younger than 55 years. CONCLUSIONS: The dark-adapted pupil diameter is an important clinical variable when planning refractive surgery. Surgeons can compare a patient's dark-adapted pupil diameter with the results of this population study to identify outlier measurements, which may be erroneous, and repeat testing prior to surgery.

Cautery fixation for amniotic membrane transplant in pterygium surgery.

PURPOSE: To report a technique using cautery fixation of the amniotic membrane transplant in pterygium excision. METHODS: The amniotic membrane transplant is oversized 3-4 mm in both dimensions (1.5-2 mm on each side). The transplant is placed in position, and the excess is tucked subconjunctivally 270 degrees. Limbal fixation sutures using 9-0 Vicryl in a buried fashion are placed, and then, amniotic membrane transplant (AMT) overlying the cornea is excised. Cautery fixation of the AMT in a grid pattern using the eraser tip is performed. The cautery power is started low and titrated up until the appropriate reaction of the graft is noted upon application. Forceps are used for countertraction to prevent the eraser tip from lifting the AMT graft after fixating it to the underlying episclera. RESULTS: This technique was used on 17 consecutive patients with pterygia (12 primary and 5 recurrent). Average surgical time was 22.65 ± 2.57 minutes. No AMT malposition, dislocation, or loss and no granuloma formation were experienced. Although follow-up up to this point is short (average: 7.12 months, range: 2-18 months), no recurrences have occurred. CONCLUSIONS: This technique provides a quick, inexpensive, and effective method of AMT fixation for use in pterygium surgery.

The effect of gender and iris color on the dark-adapted pupil diameter.

PURPOSE: The aims of this study were to assess the utility of digital color sensing to quantify iris color using digital photographs and to determine whether gender or iris color affects the dark-adapted pupil diameter (DAPD). METHODS: Subjects aged 18-80 years (N = 263) with no eye disease had their right DAPD measured after 2 min of dark adaptation at 1 lux using the NeurOptics pupillometer. A high-resolution digital slit lamp photograph of the iris was taken, and iris color was subjectively classified as blue, blue-green, green-brown, light brown, or dark brown. The digital photographs were objectively measured on-screen with the Minolta TV Color Analyzer II using the Commission Internationale de l'Eclairage system of color description. Regression analyses were performed to identify correlations between subjective iris color, Commission Internationale de l'Eclairage measurements, and DAPD. RESULTS: Gender and iris color had no effect on the DAPD. The Minolta TV Color Analyzer could discriminate all blue eyes (blue and blue-green) from all brown eyes (light and dark) but could not distinguish between shades of blue or shades of brown. Green-brown irises had no unique chromatic properties and could not be distinguished from other colors using our technique of digital color analysis. The Minolta device was simple and efficient to use. CONCLUSIONS: Contrary to long-held beliefs, female patients and blue-eyed patients do not have larger DAPD. Digital color sensing is a useful technique for objectively describing iris color.

Clinical performance of a handheld digital infrared monocular pupillometer for measurement of the dark-adapted pupil diameter.

PURPOSE: To compare the accuracy of a handheld infrared digital pupillometer and digital infrared photography for measurement of the dark-adapted pupil diameter. SETTING: Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA. METHODS: The right horizontal pupil diameter in healthy volunteers was measured using a NeurOptics PLR-200 pupillometer and then videographed using the infrared function of a CyberShot video camera after 2 minutes and 5 minutes dark adaptation at 1 lux ambient illumination. The best still image was extracted from the video file, and the horizontal pupil diameter was determined by comparison against an internal photographic length standard using digital image software. Accommodation and alertness were controlled during testing. RESULTS: The mean horizontal pupil diameter by infrared photography after 2 minutes of dark adaptation by subject age was 7.71 mm for ages 20 to 29 years, 6.80 mm for ages 30 to 39 years, 6.53 mm for ages 40 to 49 years, 5.94 mm for ages 50 to 59 years, and 6.01 mm for ages 60 to 69 years. The mean difference (infrared photography minus pupillometer) was +0.09 mm (range +0.30 to -0.14 mm) at 2 minutes of adaptation and +0.07 mm (range +0.25 to -0.13 mm) at 5 minutes. CONCLUSIONS: The pupillometer accurately measured the horizontal pupil diameter at 1 lux, with no measurement more than 0.3 mm different from infrared photography measurements. The pupillometer had a slight negative bias that is unlikely to introduce an error greater than 0.5 mm in clinical measurements.

Salzmann nodular degeneration.

PURPOSE: To describe the characteristic, clinical, and epidemiological features of Salzmann nodular degeneration. METHODS: Retrospective review of cases. All patients with diagnosis of Salzmann nodular degeneration examined on the Cornea and External Disease Service in the Department of Ophthalmology and Vision Science at the University of California, Davis, were included in this review. Demographic features, clinical characteristics, treatment regimens, surgical procedures, and outcomes were recorded. Descriptive statistics, correlation statistics in bilateral cases, and simple regression models were constructed to assess the effect of potential indicators of severity. RESULTS: One hundred eighty eyes of 108 patients were included in this review. Seventy-nine patients (72.2%) were female and 29 (27.8%) were male. Seventy-two patients had bilateral disease. The mean age for all patients was 60.8 (13-92) years, and the mean follow-up time was 61.2 months (0-357 months). 76.1% of all eyes were from White. Mean logarithm of the minimum angle of resolution best-corrected visual acuity was 0.24 (Snellen equivalent 20/35, range -0.12 to 2.60, SD 0.44). Decreased visual acuity was the most common symptom in 30.6% of patients. The visual axis was affected in 30% of the cases. Meibomian gland dysfunction was the most common coexistent condition, identified in 41.7% of the cases. For bilateral cases, Spearman correlations for best-corrected visual acuity, magnitude of astigmatism, spherical equivalent, and disease extension were statistically significant (P = 0.001). The number of quadrants affected was found to be a significant predictor for astigmatism (P = 0.01). Surgery was indicated in 41 eyes of 30 patients. Decreased visual acuity was the most common indication for superficial keratectomy. Patients with more than 1 quadrant of the cornea affected or those in which the central visual axis was involved were more likely to require surgery (P = 0.015 and 0.0001, respectively). The surgical outcome was satisfactory in 90.2% of the cases; 9 eyes (21.9%) developed recurrences. CONCLUSIONS: Salzmann nodular degeneration is a disease of uncertain etiology in which inflammation of the ocular surface may play a role. It predominantly affects women in the sixth decade of life. Management with conservative therapy is generally adequate, and in cases that require surgical intervention, simple nodulectomy is usually effective.

Histopathology of deep anterior lamellar keratoplasty with pneumatic dissection: the "big-bubble" technique.

PURPOSE: To describe characteristic histopathologic markers in deep anterior lamellar keratoplasty (DALK) using pneumatic dissection: Anwar "big-bubble" technique. METHODS: Case reports. Deep stromal buttons from 2 patients with keratoconus who had undergone DALK surgery using the "big-bubble" technique were examined by light microscopy. RESULTS: The histopathology of excised corneal buttons demonstrated multiple intrastromal spaces consistent with air bubbles. Apical stromal thinning seen clinically was not as readily appreciated on histopathology. CONCLUSIONS: Pneumatic dissection in DALK produces diffuse intrastromal air bubbles that may mask the corneal thinning that usually characterizes keratoconus histopathologically. This is a characteristic finding of which ocular pathologists and corneal surgeons should be aware.

Boston type 1 keratoprosthesis: the university of california davis experience.

PURPOSE: To compare the University of California Davis experience using the Boston keratoprosthesis with the Boston Keratoprosthesis Study Group's initial report. DESIGN: Retrospective chart review. PARTICIPANTS: We analyzed 30 eyes of 28 patients who previously underwent Boston type 1 keratoprosthesis surgery at our institution between 2004 and 2008. METHODS: Preoperative, intraoperative, and postoperative parameters were collected and analyzed. MAIN OUTCOME MEASURES: Visual acuity and keratoprosthesis stability. RESULTS: Preoperative diagnoses were failed graft (26 eyes, 87%), chemical injury (3 eyes, 10%), and Stevens-Johnson syndrome (1 eye, 3%). Twenty eyes (66%) had preoperative glaucoma. Preoperative best-corrected visual acuity ranged from 20/150 to light perception and was <20/200 in 83% of eyes. At an average follow-up of 19 months (range, 1-48; SD, 13.8; and median, 13), postoperative vision improved to >or=20/200 in 77% of eyes. Among eyes at least 1 year after the operation (16 eyes), vision was >or=20/200 in 75% of eyes and >or=20/40 in 25% of eyes. At an average follow-up of 19 months, retention of the initial keratoprosthesis was 83.3%. CONCLUSIONS: The Boston type 1 keratoprosthesis is a viable option after multiple keratoplasty failures or in conditions with a poor prognosis for primary keratoplasty. Patients with autoimmune disease are at higher risk for complications. The University of California Davis experience seems equivalent to the initial report of the Boston Keratoprosthesis Study Group. With longer follow-up, additional surgical procedures may be required but good anatomic and functional outcomes can be maintained.

The castroviejo square graft: wound healing after 51 years.

PURPOSE: To describe the histopathologic characteristics of a 51-year-old Castroviejo square graft that remained functional for more than 50 years and to describe the wound-healing characteristics over this period of time. METHODS: An 80-year-old woman with a history of keratoconus underwent penetrating keratoplasty with square grafts in 1956 and 1957 in the right and left eyes, respectively. The graft from the right eye was replaced in 2007, and the corneal specimen was submitted for histopathologic analysis. RESULTS: Light microscopy demonstrated a smooth transition between host and donor stroma. Descemet's membrane was markedly thickened (>40 m) and laminated, and a very thin retrocorneal membrane was visible at high magnification. CONCLUSIONS: This case provides an opportunity to observe the histopathology of corneal wound healing over a period of more than half a century.

Time- and temperature-dependent stability of growth factor peptides in human autologous serum eye drops.

PURPOSES: To develop a step-by-step production method for human autologous serum (AS) eye drops that was broadly compliant with US Food and Drug Administration requirements for reinjection of processed biological substances. To determine optimum storage conditions for AS eye drops by measuring the concentration of growth factor peptides (GFP) as a function of storage temperature and storage duration. METHODS: AS derived from the blood of 3 healthy male volunteers was produced using a closed, vacuum-driven, cascade-filtration system under sterile, low-pyrogen conditions. In-process controls included methods for monitoring protein electrophoretic mobility and degradation rate and the content of free hemoglobin and endotoxin. Stability of transforming growth factor beta1, substance P, nerve growth factor, calcitonin gene-related peptide, insulin-like growth factor 1, and epidermal growth factor was evaluated at -15 degrees C, +4 degrees C, +25 degrees C, +37 degrees C, and +42 degrees C at different time intervals (hours to weeks). The main outcome measures were the concentrations of GFP, endotoxin, and lipid peroxidation by-products (a proxy measure for protein degradation) in dilute AS. RESULTS: The stability of GFP varies: transforming growth factor beta1, nerve growth factor, epidermal growth factor, and insulin-like growth factor 1 were more temperature and time resistant, but substance P and calcitonin gene-related peptide significantly degraded at +4 degrees C in 24 hours. Endotoxin and lipid peroxidation by-products were not significantly increased by processing. CONCLUSIONS: This pilot study developed a closed, cascade-filtration system that was an effective method for the production of high-quality, low-pyrogen AS. The processing method broadly complied with Food and Drug Administration requirements for reinjection of biological substances. Variable GFP stability was observed at +4 degrees C and above. For clinical use, AS should be packaged in daily-use containers, which should be stored frozen; the container in active use should be refrigerated between doses.

Serum growth factor analysis in dry eye syndrome.

BACKGROUND: To perform a comprehensive serum growth factor analysis in dry eye syndrome patients and to compare this with matched controls. METHODS: Six female dry eye syndrome patients and six age- and gender-matched controls were recruited. Whole blood was collected, allowed to clot and then centrifuged. Serum was extracted by using sterile technique. Enzyme-linked immunosorbent assays were performed to quantify serum growth factor levels. RESULTS: Levels of transforming growth factor-beta 1 and 2 (TGF-beta1 and beta2), nerve growth factor (NGF), insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), acidic and basic fibroblast growth factor (FGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), platelet-derived growth factor-AA, AB and BB (PDGF-AA, AB and BB), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and glial cell line-derived neurotrophic factor (GDNF) were quantified, and statistical analysis was performed by using the Mann-Whitney U-test with the Bonferroni correction. CONCLUSIONS: No significant difference was found between serum growth factor levels in dry eye syndrome patients versus controls. Our study provides comprehensive analysis of serum growth factor levels in autologous serum eye drops produced from ocular surface disease patients. A knowledge of growth factor levels in serum may be important because of the increasing use of autologous serum eye drops in refractory ocular surface diseases and for an understanding of how topical serum may provide benefit.