Overground endoscopy in 311 Thoroughbred racehorses: findings and correlation to resting laryngeal function.

OBJECTIVE: To review a large number of equine overground endoscopy (OGE) examinations to determine the incidence of dynamic upper airway obstructions (DUAO); correlations were explored with laryngeal endoscopy findings at rest and abnormal exercising respiratory noise. METHODS: Retrospective analysis of horses presenting for OGE because of perceived poor performance and/or history of abnormal exercising respiratory noise between 2010 and 2014. Signalment, history and examination findings during resting laryngeal endoscopy and OGE were reviewed. RESULTS: Of the total examinations, 311 were reviewed. One or more DUAO were found in 249/311 horses. From 210 males (colts and geldings), 121 had arytenoid cartilage collapse (ACC) and 111 had vocal fold collapse (VFC). From 101 females, 25 had intermittent dorsal displacement of the soft palate (DDSP). Resting laryngeal function grade 4 was found in 121/311 of the study population and 92/210 of males. An association was found between horses with lower resting arytenoid abduction ability to dynamic ACC and higher resting arytenoid abduction ability with DDSP. Abnormal exercising respiratory noise was positively associated with the presence of DUAO. CONCLUSIONS: Multiple DUAO in association with abnormal exercising respiratory noise was a common finding in horses examined for poor performance. This study highlights the importance of OGE in accurately diagnosing the nature of DUAO associated with poor performance.

Results of penetrating keratoplasty using a double running suture technique.

The results of 84 consecutive penetrating keratoplasties in which a double running suture technique was used are presented herein. The second suture was smaller, looser, and more superficial than the first, causing less corneal distortion, thus allowing better visual acuity. The two sutures were removed at two and 12 months after transplantation. The visual acuities attained were almost as good at three months as at 13 months, and the graft curvature did not change notably from three to 12 months after keratoplasty. There were only two instances of postoperative wound dehiscence (2.4%). Thus, the double running suture technique allowed early visual rehabilitation without increasing the risk of corneal dehiscence from early suture removal.

Sodium hyaluronate exchange in posterior chamber lens implantation.

A method for replacing sodium hyaluronate with balanced salt solution (BSS) at the end of cataract surgery is described. The technique is performed by using an automated irrigation/aspiration machine and three substance exchanges: sodium hyaluronate for BSS, BSS for air, and air for BSS. The objective of the technique is to protect the corneal endothelium from intraocular-lens-induced trauma and to keep the lens in the bag. This is accomplished by preventing even momentary anterior chamber shallowing through the maintenance of a relatively constant anterior chamber volume during the exchanges.

Retinal tears and detachments after extracapsular cataract surgery.

A review of 3,120 consecutive cases of extracapsular cataract extraction revealed a retinal detachment incidence of 0.8% and a retinal tear incidence of 0.9%. Approximately 85% of all tears and detachments occurred within the first three years of cataract surgery. Analysis of the retinal detachment group identified several risk factors. These included young age, male sex, axial length greater than 25 mm, primary posterior capsulotomy, and previous retinal surgery in the fellow eye. In the retinal tear group, the risk factors were young age and previous retinal surgery in the fellow eye. Visual results were excellent with an average of one line of acuity lost after successful macula-on and macula-off detachment surgery and no significant change after retinal tear repair. Despite multiple surgeries, the retinas in two detachments were lost to proliferative vitreoretinopathy.

A short haptic diameter modified J-loop intraocular lens for improved capsular bag performance.

The laboratory and clinical characteristics of a modified J-loop intraocular lens (IOL) are presented. The lens features a 6 mm polymethylmethacrylate optic with uniplanar polypropylene loops of a 12 mm overall haptic diameter. The haptic design has a low resistance to compression at all diameters down to 9 mm. The relationship of the haptic configuration to the architecture of the capsular bag facilitates easy capsular bag implantation and consistent IOL centration in eyes with small and moderate capsular bag diameters. Three hundred fourteen lenses have been implanted over a one year period with no instance of asymmetric capsular bag-ciliary sulcus IOL placement, optic decentration, or pupillary capture.

Minimal lift-multiple rotation technique for capsular bag phacoemulsification and intraocular lens fixation.

A method of capsular bag phacoemulsification is outlined step-by-step. The surgical technique has proven safe and efficient and preserves the architecture of the capsular bag for hard or soft intraocular lens implantation. It represents a practical, modern method for cataract extraction and intraocular lens implantation.

Bimodal capsular bag phacoemulsification: a serial cutting and suction ultrasonic nuclear dissection technique.

A technique for emulsifying the lens nucleus within the capsular bag is presented. The circular continuous tear anterior capsulotomy (capsulorhexis) and nucleus hydrodissection, which are components of the technique, are identified. The concept of isolated cutting and suction as independent actions of the 45-degree ultrasonic phaco-emulsification tip is discussed. The two actions are achieved by alternating the orientation and action of the 45-degree ultrasonic tip in a multiple rotation nuclear dissection technique. The nucleus is collapsed and drawn centrally without aspirating nuclear material while the tip's aperture is near the lens capsule. This technique prevents the ultrasonic tip aperture from bursting through the peripheral nuclear shell and thus reduces the risk of capsular aspiration and vitreous loss.

Hybrid nuclear dissection technique for capsular bag phacoemulsification.

A bimanual phacoemulsification technique for dissecting and removing the firm lens nucleus is described. The technique is a surgical hybrid that combines concepts developed by several surgeons. Bimanual posterior and peripheral nuclear bowl fiber separation (nuclear fracture) has been incorporated into the anatomic dissection of the lens within the capsular bag. This dissection is accomplished with the 45-degree tip on separated nuclear components in situ after capsulorhexis. Combining the best features of various techniques permits this hybrid method to be applied to firm cataracts by most surgeons currently performing phacoemulsification.

Capsular bag distension after endophacoemulsification and posterior chamber intraocular lens implantation.

Six cases of capsular bag distension after capsulorhexis, endophacoemulsification, and posterior chamber intraocular lens (IOL) implantation are presented. Five cases had prominent posterior subcapsular cataracts preoperatively. In three cases, the anterior chamber depths were shallower and the apparent refractive errors were more myopic than normal after surgery. All six cases exhibited an apparent early complete sealing of the anterior capsular remnant against the anterior IOL optic. In each case, the capsular bag contained moderate particulate debris and flare while the adjacent vitreous and anterior chambers were clear. I suspect the particles are epithelial cell and cortical debris suspended in a fluid comprising lens epithelial protein, cellular breakdown products, balanced salt solution, and water. Five cases have received no specific treatment. In one case, a neodymium:YAG laser anterior capsulotomy allowed a forward egress of fluid from the distended capsular bag and a return to normal pseudophakic anatomy.

Acute intraoperative suprachoroidal hemorrhage in extracapsular cataract surgery.

The incidence of acute intraoperative suprachoroidal hemorrhage (AISH) was studied in 2,839 consecutive extracapsular cataract extraction cases operated by nucleus expression and phacoemulsification. Twenty-five eyes (0.9%) were identified with this complication. Acute intraoperative suprachoroidal hemorrhage was defined as the acute accumulation of fluid in the suprachoroidal space which resulted from a presumed suprachoroidal hemorrhage at the time of surgery. Preoperative risk factors for the development of this complication included advanced age and the presence of glaucoma. Sex, controlled hypertension, long axial length, and method of cataract removal could not be identified as significant risk factors. Recognition of the early signs of AISH and initiation of rapid wound closure followed by the completion of secondary operations performed the next day helped to meet the surgical objective and to provide excellent visual results, with 21 eyes (84%) having a visual acuity of 20/30 or better.

Modified insertion technique for the SI-18NB intraocular lens.

The 14 mm polypropylene haptic structure of the AMO SI-18NB is extremely soft for safe small incision insertion. The material has a tendency to lose its memory and experience a permanent alteration in shape if it is bent too much during implantation. An alternative surgical technique that spares extreme haptic distortion and improves centration of the intraocular lens optic is presented.

Analysis of capsular bag defects and intraocular lens positions for consistent centration.

Radial anterior capsular tears frequently occur in posterior-chamber iris-plane phacoemulsification cases. These tears extend to the capsular bag equator and can allow the knee of an in-the-bag posterior chamber intraocular lens (IOL) to unfold a smaller anterior capsular remnant. This unfolding can allow the knee of the IOL loop to extend beyond the capsular equator, leading to IOL decentration. Typical anterior capsular radial tear configurations along with guidelines for IOL design selection and orientation after recognition of these tears are presented. Proper IOL centration was achieved in 255 of 262 patients (97%) in a study observing these guidelines.

Positive and negative dysphotopsia in patients with acrylic intraocular lenses.

PURPOSE: To report the incidence, management, and prevention of patient reports of glare and streaks around a point source of light or a dark shadow in the temporal field of vision after acrylic intraocular lens (IOL) implantation. SETTING: A private practice. METHODS: Cases in which patients complained vigorously of dysphotopsia were catalogued prospectively during the implantation experience in 6668 consecutive eyes having surgery between January 1995 and June 1999. The techniques of topical-intracameral anesthesia, temporal clear corneal incisions, and phacoemulsification were used in all cases. Alternate IOL styles were selected for use from July 1999 to April 2000. RESULTS: Fourteen cases (0.2%) were identified. The complaints resolved in 1, were diminished in 1, and were tolerated without change in 7. Five eyes of 4 patients required IOL exchange with capsular bag placement of a poly(methyl methacrylate) (PMMA) or silicone lens for resolution of symptoms. Selecting alternate IOL styles reduced the incidence of dysphotopsia. CONCLUSIONS: Glare and streaks from a point source of light represent positive photic expressions of dysphotopsia, and temporal dark shadows represent similar negative photic expressions. Both appear to be associated with shiny square-edge optics made of high-refractive-index acrylic polymer. Intraocular lenses of PMMA and silicone with rounded edges, along with square-edge acrylic IOLs with nonreflective edges, appear less likely to cause clinically significant pseudophakic dysphotopsia.

Acute intraoperative suprachoroidal hemorrhage in capsular bag phacoemulsification.

Two cases of limited (nonexpulsive) acute intraoperative suprachoroidal hemorrhage (AISH) were identified in a consecutive series of 3,096 cataract surgeries accomplished by capsular bag phacoemulsification--an incidence of 0.06%. This is lower than that reported by me in 1986 when I was using iris plane phacoemulsification (0.81%). I believe the reduction is the result of decreased anatomical distortion from reducing the number and amplitude of intraocular pressure swings experienced by the globe during surgery. The pressure swings result from technique-mandated oscillations in infusion and aspiration dynamics, which are greater in number and amplitude in the iris plane technique.

Keratometric comparison of 4.0 mm and 5.5 mm scleral tunnel cataract incisions.

Postoperative keratometric astigmatism was analyzed in 276 consecutive cases of phacoemulsification and posterior chamber lens implantation performed by one surgeon. The series was divided into two groups: one received 4.0 mm incisions and the other 5.5 mm incisions. Incision design was triplanar and required suture closure, i.e., all wounds were closed with two X-pattern 10-0 nylon sutures. Using the Cravy method, an insignificant difference in induced astigmatism was found between the groups at one day, two weeks, and one year after surgery. The average induced diopters of astigmatism for the 4.0 mm group was +0.80 +/- 0.94 at one day, +0.49 +/- 0.73 at two weeks, and -0.34 +/- 0.91 at one year; for the 5.5 mm group it was +0.69 +/- 1.07 at one day, +0.41 +/- 0.85 at two weeks, and -0.23 +/- 1.01 at one year. Two-week uncorrected visual acuity of 20/40 or better was similar for both groups. Seventy-six percent of the 4.0 mm group and 68% of the 5.5 mm group had acuities of 20/40 or better. A significant difference in the incidence of immediate postoperative hyphema was noted. The overall hyphema incidence was 9%, with a 14% and 4% incidence for 5.5 mm and 4.0 mm incisions, respectively.

Capsule contraction syndrome.

Capsule contraction syndrome is an exaggerated reduction in anterior capsulectomy and capsular bag diameter after extracapsular cataract surgery. While rarely seen with can-opener-style capsulectomies with anterior radial capsular tears, it is relatively frequent with capsulorhexis. It is particularly common in patients with pseudoexfoliation and in eyes with a history of moderately severe uveitis. Its effects, which include extreme reduction in the capsulectomy opening, malposition of the opening, reduction in equatorial capsular diameter, and displacement of the IOL, seem more exaggerated in small capsulorhexis openings and in the older patient. Neodymium: YAG laser radial anterior relaxing capsulotomies done within three weeks of cataract surgery reduce the sphincter effect of the contraction and lessen the chronic zonular-traction-related complications of the condition, which may include spontaneous IOL dislocation and retinal detachment.

Features of a modern retrobulbar anesthetic injection for cataract surgery.

No significant complications including retrobulbar orbital hemorrhage after retrobulbar anesthetic block were identified in a retrospective review of 3,415 consecutive cataract surgical cases blocked and performed by one surgeon. The technique for retrobulbar injections using a disposable retrobulbar needle is described in detail. All injections were deliberately retrobulbar, directed toward the inferior temporal muscle cone, and were given immediately prior to cataract surgery by the surgeon.

Performance comparison of the Alcon Legacy 20000 1.1 mm TurboSonics and 0.9 mm MicroTip.

PURPOSE: To compare the efficiencies of the operative procedures, the changes in postoperative corneal endothelial cell density (ECD), and incision performance after cataract surgery using 2 different phacoemulsification tips. SETTING: Wolfe Clinic, Marshalltown, Iowa, USA. METHODS: A randomized prospective study of 119 consecutive cases was conducted. All patients were adults having phacoemulsification using a modified in situ fracture technique. All cases were done by 1 surgeon using the Alcon Legacy 20000 phacoemulsification machine with normal vacuum cassettes and tubing. One of 2 45 degree phacoemulsification tips was used: the 1.1 mm TurboSonics (n = 65) or the 0.9 mm MicroTip (n = 54). Measurements at the time of surgery included metered phacoemulsification time and mean phacoemulsification power. Corneal keratometry and ECD by contact specular microscopy were determined preoperatively and 10 weeks postoperatively. RESULTS: The mean metered phacoemulsification time was statistically significantly different between the 2 groups: 1.1 mm TurboSonics = 1.25 minutes; 0.9 mm MicroTip = 1.66 minutes. The mean ultrasound power was also significantly different: 1.1 mm TurboSonics = 52.98%; 0.9 MicroTip = 49.07%. Loss of corneal ECD was not significantly different: 1.1 mm TurboSonic = 3.68%; 0.9 mm MicroTip = 5.79%. Mean diopters of induced incisional keratometric flattering was similar: 1.1 mm TurboSonics, 0.32 diopters (D) +/- 0.61 (SD); 0.9 mm MicroTip, 0.25 +/- 0.49 D. There were no cases of anterior radial capsule tear, posterior capsule tear, vitreous loss, iris aspiration, suture closure, or incision leak. CONCLUSIONS: Although a longer mean metered phacoemulsification time was required with the 0.9 mm MicroTip, corneal endothelial cell loss and incisional keratometric performance were not different from those of cases in which the larger 1.1 mm TurboSonics tip was used. Both tips can be used effectively and safely for phacoemulsification of the human cataract.

Performance comparison of the Alcon Legacy 20000 1.1 mm TurboSonics and 0.9 mm Aspiration Bypass System tips.

PURPOSE: To compare the efficiencies of the operative procedures and the reductions in postoperative corneal endothelial cell density (ECD) after cataract surgery using 2 different phacoemulsification tips and their associated cassettes and tubing. SETTING: Wolfe Clinic, Marshalltown, Iowa, USA. METHODS: A randomized prospective study of 100 consecutive cases was conducted. All patients were adults having phacoemulsification using a hybrid in situ fracture technique. All cases were performed by 1 surgeon using the Alcon Legacy 20000 phacoemulsification machine. One of 2 45 degree phacoemulsification tips and associated cassettes and tubing were used: the 1.1 mm TurboSonics with normal tubing (n = 47) or the 0.9 mm Aspiration Bypass System (ABS) tip with high-vacuum cassettes and tubing (n = 53). Measurements at the time of surgery included metered phacoemulsification time, percentage power used, total time spent in the phacoemulsification process, and milliliters of balanced salt solution (BSS) used. Corneal ECD was determined preoperatively and 10 weeks postoperatively. An independent statistician performed 2-sample t tests or Wilcoxon rank sum tests on the data. RESULTS: There were no cases of anterior radial capsule tear, posterior capsule tear, vitreous loss, iris aspiration, incision leak, or suture closure. There was no correlation between amount of corneal ECD loss and any operative variable measured. Similar measurements for the 1.1 mm TurboSonics and the 0.9 mm ABS included, respectively, ECD loss 7.34% and 8.22%; metered phacoemulsification time 1.29 and 1.22 minutes; total time of the phacoemulsification process 113 and 105 seconds. There were statistically significant differences between the 1.1 mm TurboSonics tip and 0.9 mm ABS tip performance in mean power percentage overall (52% versus 48%) and overall BSS volume used (85 versus 76 mL). CONCLUSIONS: The 0.9 mm ABS phacoemulsification tip used with the high-vacuum cassette and tubing provided the physical advantages of tip-size reduction while requiring similar ultrasonic power and BSS volumes as the 1.1 mm TurboSonics tip with standard cassette and tubing. Together, they provide a wider available dynamic range in which to integrate ultrasonic power, higher vacuum, and higher aspiration flow rates to improve the efficiency and ease of use than the standard 1.1 mm TurboSonics cataract operation.

Transverse astigmatic keratotomy combined with phacoemulsification and intraocular lens implantation.

Transverse astigmatic keratotomy is a surgical technique to correct preoperative corneal astigmatism during cataract surgery. The operative technique is described and the results of my first 40 cases are reviewed. The average keratometric astigmatism for this group before surgery was 2.6 dipoters (D). The average reduction in astigmatism was 1.5 D, which yielded a final residual average astigmatism of 1.1 D after surgery. Cases of substantial astigmatism showed the most improvement. Less improvement was seen in cases of minimal preoperative astigmatism. No increase in net keratometric astigmatism was seen in any of the eyes studied. Minor complications were limited to several small corneal abrasions created by the front-cutting diamond blade and one late temporary wound dehiscence. The only serious complication was one case of corneal macroperforation. Recommendations for handling this complication and future high astigmatism cases are given.