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.

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.

Descemet's stripping automated endothelial keratoplasty in intraoperative floppy-iris syndrome: suture-drag technique.

Descemet's stripping automated endothelial keratoplasty avoids a full-thickness corneal procedure and provides rapid visual rehabilitation. Success depends on positioning the graft successfully while minimizing intraoperative donor endothelial trauma. Previously described techniques for graft insertion may be problematic in patients with intraoperative floppy-iris syndrome, anatomically shallow or unstable anterior chambers, or increased intraoperative posterior vitreous pressure. We describe an alternative called the suture-drag technique that may facilitate lamellar endothelial graft insertion in these special circumstances.

Continuous intraocular pressure recordings during lamellar microkeratotomy of enucleated human eyes.

PURPOSE: To analyze the course of intraocular pressure (IOP) during lamellar microkeratotomy (LMK) in enucleated human eyes using 3 microkeratome systems. SETTING: Department of Ophthalmology, Texas Tech University Health Sciences Center, Lubbock, Texas, U.S.A. METHODS: Sixteen enucleated human globes were cannulated through the optic nerve, and IOP was recorded continuously while the eyes had standard LMK flap creation. Three microkeratomes were used: Carriazo-Barraquer (Moria Inc.), Innovatome (Innovative Optics Inc.), and Hansatome (Bausch & Lomb). RESULTS: During the vacuum affixation phase, the IOP reached a mean plateau of 97.9 mm Hg with the Hansatome, 135.8 mm Hg with the Innovatome, and 150.0 mm Hg with the Carriazo-Barraquer. During applanation and cutting, the IOP rose to mean plateau of 154.7 mm Hg, 151.8 mm Hg, and 175.8 mm Hg, respectively. Statistical analysis using Kruskal-Wallis testing suggested a difference in mean IOP elevation between the 3 microkeratomes during the vacuum affixation phase (P = .0394) but no difference during the applanation and cutting phase (P = .506). CONCLUSION: The IOP during LMK was higher than previously reported, and this may increase the risk for complications in certain patient groups.

Candida glabrata endophthalmitis treated successfully with caspofungin.

A 39-year-old man with Candida glabrata endophthalmitis was successfully treated with a 28-day course of intravenous caspofungin. Presence of underlying renal insufficiency and infection with a drug-resistant strain precluded use of amphotericin B or fluconazole. Intravitreal administration of antifungals and vitrectomy were not required. The role of caspofungin in Candida endophthalmitis is discussed.

Visual field changes after laser in situ keratomileusis.

PURPOSE: To determine whether laser in situ keratomileusis (LASIK) affects the central 30-degree visual field. SETTING: University-based ophthalmology practice. METHODS: This nonrandomized clinical trial comprised 14 normal patients (27 eyes) scheduled to have LASIK for myopia or myopic astigmatism. Automated static perimetry was performed before and 6 months after surgery using the Octopus 1-2-3 perimeter and the Dynamic-32 test strategy. Patient data included sex, age, preoperative and postoperative refractive errors, preoperative and postoperative best corrected visual acuity, preoperative corneal thickness, programmed optical zone, programmed total ablation diameter, and duration of microkeratome suction. All surgery was performed using the same Alcon LADARVision 4000 excimer laser. The main outcome measures were the mean sensitivity (MS) change in the central 15-degree visual field and the MS change in the 15- to 30-degree visual field. A multivariate analysis of the MS change as a function of preoperative clinical parameters was performed. RESULTS: There was no significant change in the MS in the central 15-degree visual field; between 15 and 30 degrees, there was a statistically significant decrease of -0.82 dB +/- 1.40 (SD) (P=.01, 2-tailed t test). The decline in MS was positively correlated with refractive error and corneal thickness; it was negatively correlated with the programmed optical zone diameter. CONCLUSIONS: Automatic static perimetry can detect decreased sensitivity in the midperipheral visual field after myopic LASIK. It may be a useful quantitative subjective test for measuring the effects of future improvements in surgical technique on vision quality.

Comparison of Colvard pupillometer and infrared digital photography for measurement of the dark-adapted pupil diameter.

PURPOSE: To investigate the accuracy of pupil diameter measurement using the Colvard pupillometer and to determine the learning curve for inexperienced examiners. SETTING: Texas Tech University Health Sciences Center, Lubbock, Texas, USA. METHODS: In this population study, subjects with normal pupillary behavior were tested by 1 of 2 investigators (examiner A, examiner B). After 5 minutes of dark adaptation at 1 lux, digital infrared pupil photography of the right eye was performed, followed by measurement of the horizontal pupil diameter and vertical pupil diameter with the Colvard pupillometer. The photographs were digitally analyzed to determine the horizontal and vertical pupil diameters. During phase I of the study, examiners were masked to the results of infrared pupil photography; during phase II, they reviewed the infrared pupil photography results after each testing session. Bland-Altman plots were created to detect measurement bias; results were graphed by subject test sequence to assess learning. A test difference of less than +/-0.5 mm was considered clinically acceptable. RESULTS: Fifty-nine subjects were tested in phase I, of whom 39 had adequate infrared pupil photography for analysis; 40 were tested in phase II, of whom 34 were included. The mean age of the analyzed subjects was 27 years (range 18 to 44 years). For all subjects, the infrared pupil photography median horizontal pupil diameter was 7.09 mm +/- 0.75 (SD) (range 5.44 to 8.79 mm); the median vertical pupil diameter was 7.22 +/- 0.79 mm (range 5.45 to 9.10 mm). Examiner A initially had a negative bias (Colvard pupillometer value less than infrared pupil photography value) for both horizontal and vertical pupil diameter measurements, which resolved during phase I after 23 subjects were tested; 18 of the final 19 subjects tested (11 phase I, 8 phase II) showed a test difference of less than 0.5 mm for all readings. The pupil diameter did not affect the bias. Examiner B had a strong positive bias that persisted throughout the study. Testing 26 subjects in 5 sessions during phase II did not improve the accuracy. During the final testing session, 3 of 8 subjects had a test difference of 0.5 mm or more in at least 1 dimension. The pupil diameter did not affect the bias. CONCLUSION: The Colvard pupillometer is susceptible to user errors causing unidirectional bias and seems to have a steep and variable learning curve.

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.

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.

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.

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.

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.