Change in optic disk topography after trabeculectomy

PURPOSE: To investigate the relationship between optic disk topography and intraocular pressure before and after trabeculectomy with confocal scanning laser ophthalmoscopy. METHODS: The eyes of 49 consecutive patients undergoing trabeculectomy at a university-based glaucoma practice underwent preoperative and postoperative imaging using a confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph). Three images of one eye of each patient were obtained with a 15-degree field of view. Preoperative images were obtained approximately 2 months before surgery (mean +/- SD, 2.4 +/- 1.6 months). Postoperative images were obtained at least 3 months after surgery (mean, 4.5 +/- 2.6 months). RESULTS: Mean preoperative intraocular pressure, postoperative intraocular pressure, and percent change in intraocular pressure respectively were 23.1 +/- 6.8 mm Hg, 12.7 +/- 7.1 mm Hg, and 43.8% +/- 29.9%. A significant association (P < .01) was found between percent decrease in intraocular pressure and decreases in cup area, cup volume, and cup/disk area ratio as well as between percent decrease in intraocular pressure and increases in rim area, rim volume, mean height contour, retinal cross-section area, and height in contour. Between 11.7% and 31.2% of the variability (R2) in these parameters was explained by the percent change in intraocular pressure. Topography changes were more strongly associated with percent change than with mean change in intraocular pressure. We found no association between percent decrease in intraocular pressure and reference plane height or maximum cup depth. CONCLUSIONS: Changes in optic nerve topography were associated with reduction in intraocular pressure after trabeculectomy.     

Veterinary ethics in the liberalized market: the Zambian environment

BACKGROUND: This study was performed to assess the functional capacity of the survivors of septal myectomy for the treatment of hypertrophic obstructive cardiomyopathy in long-term follow-up as assessed by dobutamine stress echocardiography. METHODS: Sixty-nine patients with hypertrophic obstructive cardiomyopathy underwent septal myectomy between 1975 and 1996. The mean age was 25.4 +/- 13.6 years (range, 6-58 years), and 10 of the patients were women. The early mortality was 4.3%. Hospital survivors (95.7%) were followed up for a mean of 43.8 +/- 28.7 months (range, 6-114 months). RESULTS: The postoperative mean functional capacity of the group was 1.47 +/- 0.56. No late deaths were reported. Forty-nine patients (74.2%) were evaluated with standard echocardiographic techniques, and 29 (43.9%) patients underwent dobutamine stress echocardiography. There was a significant decrease in the thickness of the interventricular septum after surgery. The mean preoperative and postoperative septal thickness was 1.99 +/- 0.59 cm (range, 1.3-3.8 cm) and 1.55 +/- 0.41 cm (range, 0.96-2.8 cm), respectively (p < 0.004). The mean posterior wall thickness was significantly less than the preoperative value (p = 0.008) and the left ventricular end-diastolic diameter was slightly greater in the postoperative measurements, but the difference was not significant (p = 0.162). Postoperative left ventricular outflow systolic gradients were reduced significantly when compared with preoperative values (preoperative mean, 78.4 +/- 33.6 mm Hg, range, 50-212 mm Hg versus postoperative mean, 17.9 +/- 15.9 mm Hg: range, 0-40 mm Hg; p < 0.0001). CONCLUSION: Septal myectomy for patients with hypertrophic obstructive cardiomyopathy is a safe procedure with excellent clinical and functional results in the long-term follow-up.     

Avoiding complicated shunt systems by open fenestration of symptomatic fourth ventricular cysts associated with hydrocephalus

BACKGROUND: The effect of thyroid orbitopathy on intraocular pressure (IOP) remains controversial. We carried out a study to determine the effect of orbital decompression surgery on the IOP in patients with advanced thyroid orbitopathy. METHODS: The records of 12 consecutive patients (22 eyes) who underwent decompression surgery for severe thyroid orbitopathy between 1985 and 1996 were reviewed. All patients were maintained on essentially the same medications before and after surgery. The IOP readings, obtained by means of applanation tonometry in primary gaze, from the pre- and postoperative visits were recorded, and the net change was calculated. RESULTS: The mean preoperative and postoperative IOP values were 19.8 mm Hg and 16.8 mm Hg respectively, a significant difference (p = 0.008). Seven of eight eyes with an IOP of 21 mm Hg or greater preoperatively had a postoperative IOP less than 21 mm Hg; these eyes showed a mean decrease in IOP of 5.6 mm Hg. The degree of preoperative IOP elevation was found to be a strong predictor of the amount of IOP lowering after surgery (p = 0.014). INTERPRETATION: Our results support the concept that orbital congestion associated with thyroid orbitopathy produces an increase in IOP by elevation of episcleral venous pressure (EVP) and that orbital decompression may reduce the IOP by decreasing EVP. Decompression surgery may obviate the need for more aggressive management of glaucoma in patients with severe thyroid orbitopathy.     

Effect of local administration of mitomycin C on intraocular pressure

BACKGROUND: Animal studies suggest that the decrease of intraocular pressure after application of mitomycin C is particularly mediated by toxic effects on the substance of ciliary body. Moreover it has been shown that the concentration of mitomycin C after topical application in the aqueous humour is as high when performing fistulating surgery. In this prospective study we wanted to investigate whether the topical application of mitomycin C would result in a significant decrease of intraocular pressure. PATIENTS AND METHODS: Forty-one eyes of 41 patients underwent pterygium surgery using a bare sclera technique. Afterwards phototherapeutic keratectomy with the excimer laser (193 nm) was performed in the area of the excision. In hospital mitomycin C eye drops (0.02%) were given twice daily for four days. The intraocular pressure of treated and untreated eyes was measured with applanation tonometry at least three times per day preoperatively, postoperatively at the fourteenth day and after 6 month. RESULTS: Mean intraocular pressure of the treated eyes was preoperatively 15.73 +/- 2.35 mm Hg, 14 days postoperatively 15.92 +/- 2.79 mm Hg and at the last examination 15.86 +/- 2.39 mm Hg. For untreated eyes the mean intraocular pressure was preoperatively 15.70 +/- 2.04 mm Hg, after 14 days 15.76 +/- 2.96 mm Hg and at the last examination 15.89 +/- 2.67 mm Hg. Consequently there was no statistically significant change of intraocular pressure in the eyes treated with mitomycin C. Furthermore there were no significant differences of intraocular pressure between treated and untreated eyes at any time of postoperative check-up. CONCLUSION: The short-term local application of mitomycin C did not result in a detectable change of intraocular pressure and is therefore probably an alternative to intraoperative application during filtration surgery.     

Glaucoma drainage implants in pediatric patients

To assess the use of drainage implants in pediatric patients with glaucoma refractory to conventional medical and surgical therapy, we retrospectively reviewed 20 consecutive eyes in children 10 years of age or younger treated with 16 Molteno (three of which were removed and replaced with second Molteno shunts) and seven Baerveldt implants. The age of the patients ranged from 1 month to 10 years (mean, 3 years). The patients had undergone a mean of two previous failed glaucoma procedures (range, one to six). The mean intraocular pressure (IOP) prior to drainage tube implantation was 37 +/- 4 mm Hg, compared with a mean of 18 +/- 6 mm Hg following surgery, with average postoperative follow up of 25 months (range, 8 to 41 months). The overall success, defined as IOP < or = 21 mm Hg without further surgical therapy, was 80%. Postoperative glaucoma medications were required in 75% of patients. There were 23 complications, one of which resulted in decreased visual acuity. These findings demonstrate that drainage tube implants can be effective in lowering IOP in uncontrolled pediatric glaucomas. Patients often require postoperative glaucoma medications and close monitoring for complications.     

Timolol gel versus acetazolamide in the prophylaxis of ocular hypertension after phacoemulsification

PURPOSE: To compare postoperative intraocular pressure (IOP) after administration of acetazolamide and timolol following phacoemulsification and intraocular lens implantation. SETTING: Ophthalmic Consultants of Long Island, Rockville Centre, New York, USA. METHODS: Sixty patients were included in a prospective, randomized, masked trial. The patients received either two doses of oral, sustained-release acetazolamide (Diamox Sequels) or a single dose of topical timolol 0.5% gel (Timoptic XE). Intraocular pressure was measured by Goldmann applanation tonometry preoperatively and 1 day postoperatively. RESULTS: Mean preoperative IOP was 16.4 mm Hg. One day postoperatively, it was 19.5 mm Hg in the oral acetazolamide group and 15.9 mm Hg in the timolol gel group. One patient in the acetazolamide group developed significant adverse reactions. CONCLUSION: Prophylactic use of topical timolol 0.5% gel for viscoelastic-induced ocular hypertension after cataract extraction appears to offer better IOP control than oral acetazolamide and has potentially fewer adverse systemic effects.     

Incidence of complications following 5-fluorouracil with trabeculectomies

To investigate the incidence of complications reportedly caused by the use of 5-fluorouracil (5-FU) in glaucoma filtering surgery, we performed trabeculectomy with 5-FU on 57 eyes of 56 patients with advanced glaucoma. The mean preoperative intraocular pressure was 34.8 mm Hg. The most frequent complication encountered was superficial punctate keratopathy (26%), followed by shallowing of the anterior chamber (12%), choroidal detachment (9%), and flap retraction (7%). We, however, did not encounter any cases of confluent corneal epithelial defect, subepithelial scarring, or striate melanokeratosis which are usually described with the use of 5-FU. With a mean follow-up of 7.1 months, an intraocular pressure less than 16 mm Hg without hypotensive therapy were achieved in 73.7% of cases, and less than 21 mm Hg without hypotensive therapy in 86%. Considering the low incidence of complications and the high success rate, we recommend the use of 5-FU in routine glaucoma filtering surgery.     

Laparoscopic esophagomyotomy without an antireflux procedure for the treatment of achalasia

Various gastroenteric surgical procedures have been attempted laparoscopically. Laparoscopic esophagomyotomy (LE) with or without fundoplication, performed for achalasia, has gained popularity. In our clinic, LE (Heller's myotomy) was performed on six patients with achalasia. All patients underwent barium esophagography, endoscopy, and esophageal manometry for diagnosis. Extramucosal myotomy was started 6 cm above the cardioesophageal junction on the left anterolateral aspect of the esophagus and continued 1 cm below this area. Endoscopic control of the distal esophageal mucosa and the stomach was carried out under direct laparoscopic visualization following the completion of myotomy during the operation. LE was completed without complication in five patients. In one patient (16%), mucosal perforation occurred after myotomy during endoscopic control and was repaired with endostitches. There were no postoperative complications. The average hospital stay was 3 days. Three of the six patients agreed to 24-h pH monitoring, the results of which showed no evidence of reflux. All patients were completely symptom free in the postoperative period. The average preoperative lower esophageal sphincter pressure was 44 mm Hg, whereas in the early postoperative period and 6 months later, it was 11 mm Hg. There was no dysphagia or reflux esophagitis during the follow-up period (range 12 to 24 months). LE is associated with low morbidity and a high success rate, comparable with an open procedure, and can be done without an antireflux procedure.     

First trimester isolated fetal nuchal lucency: significance and outcome

BACKGROUND: In this retrospective study the postoperative alteration of intraocular pressure after cataract extraction and posterior chamber lens implantation was analyzed statistically. The influence on intraocular pressure between different positions of the loops (sulcus versus bag) was compared. PATIENTS AND METHOD: The posterior chamber lens implantation was performed on 267 eyes with 129 sulcus implanted and 138 in-the-bag implanted intraocular lenses. The average age of the patients was 74.8 respectively 71.9 years, with an equal ratio of sex. In surgery the viscoelastic experimentation of the nucleus was done via corneoscleral cut. A x-crossed suture sealed the corneoscleral wound followed by subconjunctival injection of corticosteroids. The postoperative medication for 4-6 weeks consisted of a corticosteroid and antibiotic combination. RESULTS: The average intraocular pressure of the sulcus implanted respectively in the bag implanted intraocular lenses increased from 15.4 mm Hg respectively 15.9 mm Hg preoperatively to 16.3 respectively 15.8 mm Hg at the first postoperative day. After two months the intraocular pressure decreased to 14.6 respectively 14.1 mm Hg. That means a pre- to postoperative difference of -0.8 respectively -1.8 mm Hg. CONCLUSIONS: In summary both groups showed a slight decrease in average intraocular pressure after two months. In comparison to the sulcus implanted intraocular lens the decrease of intraocular pressure was more than 1 mm Hg in case of the in the bag implanted lens. This decrease was statistically significant but may be considered of less clinical interest.     

Intraoperative mitomycin C in complicated glaucomas

Filtering surgery has been found to be less successful in certain types of glaucoma. These include young patients, those with pigmentary glaucoma, secondary glaucoma, angle recession glaucoma, aphakic or pseudophakic glaucoma, and patients requiring reoperation. This study describes the authors' attempt to evaluate the effectiveness of conventional trabeculectomy with intraoperative application of mitomycin C in such patients. Ten eyes of 8 patients were evaluated in this study. Of these cases 4 eyes (2 bilateral cases) were from the primary juvenile open angle group; 2 eyes each had pseudophakic glaucoma and previous anti-glaucoma surgery which had failed; one eye had aphakic glaucoma and the last suffered from angle recession glaucoma. The intraocular pressure was successfully controlled in all the ten eyes. The preoperative IOP ranged from 28 to 50 mm Hg and the postoperative IOP ranged from 7 to 16 mm Hg. The postoperative complications were minimal.     

Measurement of intraocular pressure after epikeratophakia

AIMS: To assess the accuracy of three commonly used tonometers in eyes after epikeratophakia. METHODS: Five eye bank eyes with sutured epikeratophakia buttons were connected to a manometer and a pressure transducer. Intraocular pressure was adjusted in 5 mm Hg increments from 0 to 50 mm Hg. The intraocular pressure was measured at each increment using a Goldmann tonometer, a pneumatonometer, and a Tono-pen. RESULTS: The difference between the manometer (actual pressure) and the Goldmann tonometer ranged from -19 to +9 mm Hg (mean (SD) overestimation 2.6 (5.8) mm Hg). The pneumatonometer error ranged from -27.5 to +5.5 mm Hg (mean (SD) overestimation 4.7 (6.1) mm Hg), and for the Tono-pen the range was -18 to +11 mm Hg (mean (SD) overestimation 0.05 (7.9) mm Hg). The correlation coefficients for the three tonometers were 0.94, 0.92, and 0.87 for the Goldmann tonometer, pneumatonometer, and Tono-pen respectively. CONCLUSION: The Goldmann tonometer had the best correlation with the manometer in eye bank eyes with epikeratophakia (correlation coefficient 0.94), but none of the tonometers was accurate over the entire range of pressures tested. Detection of glaucoma in eyes with epikeratophakia cannot rely on tonometry alone, but requires examination of the optic nerve and visual field.     

Topical plus subconjunctival anesthesia for phacotrabeculectomy: one year follow-up

PURPOSE: To evaluate the results of topical plus subconjunctival anesthesia for phacotrabeculectomy surgery and postoperative glaucoma control over 1 year. SETTING: Pacific Eye Center, Brisbane, Australia. METHODS: In this retrospective study of consecutive patients with glaucoma and cataract, topical plus subconjunctival anesthesia was used for combined phacoemulsification, posterior chamber intraocular lens implantation, and trabeculectomy (phacotrabeculectomy). Patients with proliferative diabetic retinopathy or neovascular glaucoma were excluded. RESULTS: Thirty-eight eyes had phacotrabeculectomy using topical plus subconjunctival anesthesia over 2 years. Patients reported no discomfort intraoperatively or postoperatively, and none required intravenous sedation. Eighty-one percent of patients achieved a best corrected visual acuity of 20/40 or better 6 months after surgery. Mean drop in intraocular pressure (IOP) was 5.91 mm Hg at 3 months and 5.86 mm Hg at 12 months, at which time IOP was controlled without additional medication in 72% of patients. There were no serious complications postoperatively. CONCLUSION: In this series, no patient reported intraoperative or postoperative discomfort and surgical results were excellent in terms of visual outcome and IOP control.     

Inflammatory breast carcinoma: comparison of survival of those diagnosed clinically, pathologically, or with both features

Although trabeculectomy is an established surgical technique for glaucoma, in some cases it does not achieve a good filtering effect despite the use of mitomycin-C (MMC). The authors have developed a new surgical technique for uncontrollable glaucoma that uses amniotic membrane to prevent postoperative adhesion of conjunctiva and sclera. They performed trabeculectomy with a limbal-based conjunctival flap using 0.4 mg/ml of MMC for 2 minutes. Amniotic membrane was then placed under the scleral flap and sutured using 10-0 nylon. Among 14 eyes of 13 patients who underwent this procedure, intraocular pressure was controlled to less than 20 mm Hg after surgery in 13 eyes, including 3 eyes that underwent a second surgery with the same technique and 2 eyes that underwent laser trabeculoplasty. The authors' results suggest that this technique is efficacious for the reduction of intraocular pressure in high-risk glaucoma patients.     

Reduced intraocular pressure after phacoemulsification and posterior chamber intraocular lens implantation

PURPOSE: To ascertain whether phacoemulsification with posterior chamber intraocular lens (IOL) implantation causes long-term reduction in intraocular pressure (IOP). SETTING: Private practice, Kempten, Germany. METHODS: Intraocular pressure was measured in both eyes of 120 consecutive patients who were unilaterally phakic after phacoemulsification a mean of 17 months +/- 17 (SD) previously. Mean age of the 36 men and 84 women was 76 +/- 10 years. Data were analyzed using binomial distribution and the Wilcoxon signed-rank test. RESULTS: The median ratio of IOP in the pseudophakic eye to IOP in the phakic eye was 0.83. The IOP was lower in the pseudophakic eye in 96 patients (80%). The median IOP was 12 mm Hg in the pseudophakic eyes and 14 mm Hg in the phakic eyes (P < .001). As measured by the interquartile range, IOP distribution was more centered in the pseudophakic than in the phakic eyes (3 versus 4). The IOP in the pseudophakic eyes remained lower to the last measurement, 5 years postoperatively, and appeared to be independent of patient age. Lower IOP in the pseudophakic eye was consistently present in patients with higher IOP in the phakic eye (16 to 22 mm Hg). CONCLUSION: Phacoemulsification with posterior chamber IOL implantation reduced IOP in most but not all patients with a preoperative IOP of 22 mm Hg or less. This reduction was maintained over several years, with the cause yet to be established. Lower IOP may decrease the risk of subsequent glaucomatous nerve damage in these patients.     

The acute pain service: effective or expensive care?

AIM: The authors investigated the safety and intraocular pressure (IOP) lowering effectiveness of trabeculectomy augmented with mitomycin C application beneath the scleral flap, and assessed the influence of preoperative risk factors on the surgical outcome. METHODS: A retrospective study of 72 consecutive high risk eyes undergoing trabeculectomy with adjunctive mitomycin C (0.2 mg/ml) applied under the scleral flap for 5 minutes was performed. Each eye was ascribed a score based on the number of preoperative risk factors, and categorised into one of three risk factor groups. Success was described as unqualified where IOP was < or = 21 mm Hg without medication and qualified where antiglaucomatous therapy was required to maintain it at such a level. A life table analysis of IOP control was calculated. RESULTS: The mean IOP (SD) fell from a preoperative level of 28.4 (6.9) to a level of 16.63 (8.06) mm Hg at the last follow up (paired Student's t test: p < 0.0001). Fifty two eyes (72%) were classed as unqualified successes. The survival rates did not differ significantly between different risk factor groups (log rank test: chi 2 = 0.967, p > 0.1). The incidence of postoperative complications compared favourably with reports of mitomycin C application between Tenon's capsule and the undissected scleral bed. CONCLUSION: The results illustrate that mitomycin C applied beneath the scleral flap during trabeculectomy in high risk eyes is associated with a success rate comparable to other modes of application. The incidence of potentially serious complications such as conjunctival wound leak and prolonged hypotony was lower than previously published data reporting sub-Tenon's administration of mitomycin C. The number and nature of preoperative risk factors do not appear to influence the surgical outcome. A possible mechanism of action is proposed.     

The bait in the Rubisco mousetrap

The authors present an account on their first results of trabeculectomy with releasable sutures, as described by Osher. The intraocular pressure before operation was on average 21.7 mm Hg (23-40 mm Hg). During the last visit (on average 2.8 months after operation) it was 13.5 mm Hg (13-15 mm Hg), incl. six eyes without treatment. Only in two eyes during the early postoperative period a shallower anterior chamber was observed. The authors recommend more extensive use of the technique of releasable suture in trabeculectomy.     

Relative strength of scleral tunnel incisions with internal corneal lips constructed in cadaver eyes

We constructed scleral tunnel wounds with internal corneal lips and sutureless closures in ten cadaver eyes without previous intraocular surgery. Each wound differed in width, total incision length, and internal corneal lip size. At a low and high range of initial intraocular pressure (IOP, 10 to 15 mm Hg or 20 to 25 mm Hg), we compared the wounds' resistance to leakage during application of external pressure. A square wound with a 4.0 mm width and 4.0 mm overall length, including a 1.5 mm corneal lip, had the optimum wound dimensions. These produced a stable incision that resisted leakage at external pressures up to 525 pounds per square inch equally well at both IOP ranges. Leakage occurred at lower external pressures for wounds with greater width, smaller corneal lips, or wound widths that were greater than wound lengths; such wounds were also more prone to leakage at the low IOP range. When constructed properly and adequately, the 4.0 mm wide scleral tunnel incision with 1.5 mm internal corneal lip is a strong and safe wound for sutureless cataract surgery.     

Determination of the facility of aqueous humor outflow in the dog, comparing in vivo and in vitro tonographic and constant pressure perfusion techniques

The gross facility of aqueous humor outflow (C) was estimated in the normal in vivo and in vitro dog eye, using tonography and constant pressure perfusion. Tonographic C value for 36 normal eyes, with the dog anesthetized with ketamine hydrochloride and acetylpromazine maleate, was 0.21 (+/- 0.14, SD); the mean tonographic value in 35 eyes with the patient anesthetized with sodium pentobarbital was 0.15 (+/- 0.09). Constant pressure perfusion of the in vivo normal dog eyes at 20 mm of Hg intraocular pressure yielded a mean C value of 0.13 (+/- 0.07) and at 30 mm of Hg 0.18 (+/- 0.13). As intraocular pressure increased from 10 to 50 mm of Hg, the rate of outflow, as determined by constant pressure perfusion, increased. The C values from in vitro constant pressure perfusion were greater than those in the in vivo eyes and deceased in most eyes as intraocular pressure was increased as compared with the in vivo preparation.     

Extracapsular cataract extraction with posterior chamber lens implantation in primary angle-closure glaucoma

PURPOSE: To evaluate long-term intraocular pressure (IOP) control after extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (IOL) implantation in patients with primary angle-closure glaucoma. SETTING: Ophthalmology Department, Groote Schuur Hospital, Cape Town, South Africa. METHODS: This retrospective study comprised 17 patients (19 eyes) with primary angle-closure glaucoma who had ECCE and posterior chamber IOL implantation. Four presented initially with acute glaucoma, 5 with subacute angle-closure glaucoma, and 8 (10 eyes) with chronic angle-closure glaucoma. In all, less than half the circumference of the angle was permanently closed. The drainage angle was evaluated preoperatively and postoperatively to monitor changes in the amount of angle closure. Intraocular pressure was measured in the early and late postoperative periods. RESULTS: On the first postoperative day, mean IOP was 17.2 mm Hg, although 5 patients (26%) had an IOP rise above 21 mm Hg despite the use of perioperative topical pilocarpine gel. After a mean follow-up of 19 months, IOP remained below 22 mm Hg without medication in 13 eyes (68%) and with topical medication in 5 eyes (26%). Mean number of glaucoma medications was reduced from 1.5/eye preoperatively to 0.5/eye postoperatively. CONCLUSION: Cataract extraction with IOL implantation resulted in good long-term IOP control in patients with primary angle-closure glaucoma, suggesting that combined cataract and trabeculectomy surgery may not be necessary to achieve long-term IOP control in these patients.     

Tourniquet pressures on pediatric patients: a clinical study

A clinical study was undertaken to evaluate pneumatic tourniquet pressures required for hemostasis in extremity surgery of pediatric patients. Occlusion pressures were measured by Doppler, and tourniquet pressures were set 50 mm above this value. Of 29 cases, 86% were determined to provide adequate hemostasis throughout the procedure. Maximum mean pressures used in the upper and lower extremity groups were 173.4 +/- 11.6 mm Hg (range: 155 to 190 mm Hg) and 176.7 +/- 28.7 mm Hg (range: 140 to 250 mm Hg), respectively, accounting for adjustments made to inadequate initial settings. This study suggests that lower tourniquet pressures than previously used may be needed to maintain adequate hemostasis in pediatric patients.