Incidence Of Hypotony Research Articles

Effect of Early Aqueous Suppression After Valved Tube Shunt Surgery for Uveitic Glaucoma

To compare outcomes of early aqueous suppression (EAS) and standard therapy (ST) after Ahmed Glaucoma Valve (AGV) implantation for uveitic glaucoma. Retrospective comparative cohort study. All patients with uveitic glaucoma underwent AGV implantation from January 2010 to October 2020 at Northwestern Medicine. Excluding the first postoperative day 1 (POD1), only eyes with IOP 10-15 mmHg at their first visit with IOP ≥ 10 mmHg were included in the main analysis. Early aqueous suppression (EAS) was defined as initiation of ocular hypotensive therapy when IOP was first 10-15 mmHg. Standard therapy was initiation of therapy at any later time. Failure was defined as IOP > 21 mmHg, < 5 mmHg, or < 20% reduction in IOP from baseline after 3 months, for 2 consecutive study visits. Hypotony was defined as IOP ≤ 5 mmHg for ≥ 2 visits. Hypertensive phase was defined as IOP > 21 mmHg for 2 consecutive visits in the first 3 months. Proportion achieving overall success; incidence of hypotony and hypertensive phase. Twenty-eight eyes of 26 patients were in the EAS group and 20 eyes of 19 patients were in the ST group, with a mean follow-up of 17.7 and 28.2 months, respectively. Baseline IOP was similar in the EAS (31.2±10.1 mmHg) and ST (34.6±12.2 mmHg) groups; P=0.18. Final IOP was lower in the EAS group (12.9±4.6 mmHg) than the ST group (16.4±5.7 mmHg; P=0.02) on 2.6±0.9 medications in the EAS group and 1.8±1.5 in the ST group (P=0.07). Overall success was achieved in 87% of EAS eyes and 74% of ST eyes (P=0.43). There were no statistically significant differences in the occurrence of additional glaucoma surgery (4%for EAS, 20% for ST; P=0.11), hypotony (7% for EAS, 0% for ST; P=0.50), or hypertensive phase (4%forEAS, 21% for ST; P=0.09). EAS was associated with a lower final IOP after AGV in uveitic glaucoma eyes; however, more medications were in use at the final visit. No statistically significant differences in overall success or the incidence of adverse events were observed. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Hypotony-associated Complications After Deep Sclerectomy: Incidence, Risk Factors, and Long-term Outcomes.

Chronic hypotony is not uncommon following deep sclerectomy (DS), but only a minor proportion of patients develop hypotony-associated complications. Numerical hypotony does not affect the visual outcomes. This study identifies factors associated with hypotony. To investigate the incidence and risk factors of hypotony and hypotony-associated complications after DS. Retrospective cohort study of 1765 eyes (1385 patients) undergoing DS with or without cataract extraction between 2001 and 2020 in 2 UK centers. Chronic hypotony was defined as intraocular pressure (IOP) ≤5 mm Hg in ≥2 consecutive visits lasting >90 days or as any IOP ≤5 mm Hg associated with hypotony-related complications or requiring surgical intervention. Clinical hypotony was defined as the presence of: serous or hemorrhagic choroidal detachment, hypotony maculopathy, flat anterior chamber requiring reformation, decompression retinopathy. The incidence of hypotony was calculated with Kaplan-Meier statistics, and Cox regression was used to identify risk factors. The median (interquartile range) age and follow-up were 76 (67 to 82) years and 45.4 (20.9 to 79.8) months, respectively. The incidence (95% confidence interval) of chronic and clinical hypotony at 5 years was 13.4% (11.5%-15.3%) and 5.6% (4.3%-6.9%), respectively. Sixteen eyes (15.7%) with hypotony-associated complications had IOP >5 mm Hg. Male sex (hazard ratio [HR]: 1.89, P=0.018), non-Caucasian ethnicity (HR: 2.49, P=0.046), intraoperative bevacizumab (HR: 3.96, P=0.01), pigmentary glaucoma (HR: 3.59, P=0.048), previous vitreoretinal surgery (HR: 5.70, P=0.009), intraoperative microperforation (HR: 4.17, P<0.001) and macroperforation (HR: 20.76, P<0.001), and avascular bleb (HR: 1.80, P=0.036) were associated with clinical hypotony. Chronic hypotony is not uncommon following DS, but clinical hypotony is infrequent. Hypotony associated-complications can occur in eyes without statistical hypotony.

Comparison of Short-term Postoperative Hypotony Rates of 23-gauge vs 25-gauge Needles in Formation of the Scleral Tract for Baerveldt Tube Insertion into the Anterior Chamber.

ABSTRACTIntroductionTo compare the early postoperative hypotony rates and intraocular pressure (IOP) in two groups of eyes using either 23-gauge (23G) or 25-gauge (25G) needle in the creation of the anterior chamber entry tract for Baerveldt tube. The primary outcome measure was incidence of hypotony, and secondary outcome measures included comparison of mean IOP and other early complications.Materials and methodsOurs was a retrospective case review of consecutive patients who underwent 350 mm2 Baerveldt implantation in two units over a 2-year period. Data including IOP and complications were collected at 1 day, 1 week, and 1 month following surgery from patients’ notes. Statistical analysis between groups was determined using the unpaired 2-tailed f-test for continuous variables and chi-squared test for categorical variables. Statistical significance was defined at the 0.05 level.ResultsA total of 58 eyes of 58 patients were included in this study. Preoperative mean IOP in the 25G group was significantly higher (26.4 ± 6.8 mm Hg) when compared with the 23G group (21.6 ± 4.0 mm Hg) (p = 0.002). The mean postoperative IOP remained significantly higher in the 25G group at day 1 (p=0.004), week 1 (p = 0.008), but not at month 1 (p = 0.744). Four patients in the 23G group had hypotony within 1 month postsurgery compared with no cases in the 25G group (chi-squared test p = 0.038).ConclusionThere was a significantly higher risk of early hypotony and lower IOP in the larger 23G group at days 1 and 7, although the IOP was similar in both groups by 1 month.Clinical significanceAfter all glaucoma drainage device (GDD) tube implantation, regardless of which needle is used to create the tract, the entry site should always be checked with 2% fluorescein drop and 10.0 nylon suture is used with or without autologous Tenon’s tissue to close any leakage.How to cite this article: Lim KS, Garg A, Cheng J, Muthusamy K, Beltran-Agullo L, Barton K. Comparison of Short-term Postoperative Hypotony Rates of 23-gauge vs 25-gauge Needles in Formation of the Scleral Tract for Baerveldt Tube Insertion into the Anterior Chamber. J Curr Glaucoma Pract 2018;12(1):36-39.

Infusion Misdirection in Microincisional Vitrectomy Surgery

To review the incidence and possible mechanisms of 2 problems caused by infusion misdirection during microincisional vitrectomy in 1 physician's practice and to find an estimate of the broader occurrence among other physicians. Observational series of 1 surgeon's cases over 2 periods. A survey also was sent to other retinal specialists. Patients undergoing microincisional vitrectomy. The physician tracked the occurrence of intraoperative hypotony and unintentional anterior chamber air infusion in his practice. A survey was sent to 2000 members of the American Society of Retina Specialists and the Retina Society. Primary outcome measure was the incidence of hypotony during microincisional vitrectomy, defined as softening of the globe to the point of corneal or scleral infolding, or both, that resolved with repositioning of the infusion cannula. The secondary outcome measure was incidence of unplanned air flow into the anterior chamber. Survey questions included frequency of observed infusion interruption and incidence of inadvertent anterior chamber air infusion. In the earlier series, of 232 vitrectomies, 37 (16%) showed signs of episodic hypotony after infusion blockage. Seven cases (3%) showed inadvertent air flow into the anterior chamber. One hundred fifty-two physicians responded to the survey. Fifty-seven percent reported infusion blockage and hypotony in 1% to 5% of cases. Fifty-nine percent reported air flow into the anterior chamber in some cases. In the later series, 12 instances of infusion blockage were noted in 118 cases. Awareness of the issue and additional attention to the infusion line taping did not prevent the problem from occurring. In the survey, most respondents reported observing both infusion interruption and inadvertent anterior chamber air infusion on occasion. Infusion misdirection resulting in hypotony or air flow into the anterior chamber seems to be infrequent, but it remains a risk. Awareness of the problem reduces the incidence, but does not eliminate it. The potential inadvertently to touch the retina, choroid, or lens increases when these events occur. Infusion misdirection can be avoided by maintaining the correct position of the cannula, which may be facilitated by an external support to the tubing.

Risk of Hypotony in Juvenile Idiopathic Arthritis–Associated Uveitis

To describe risk factors for hypotony in patients with juvenile idiopathic arthritis (JIA)-associated uveitis. Retrospective cohort study. All patients with JIA-associated uveitis (N= 108; affected eyes= 196) evaluated and followed at the Wilmer Eye Institute from July 1984 through June 2014 were included in this study. Prevalence and incidence of hypotony (intraocular pressure [IOP] <5mm Hg) and low IOP (5mm Hg ≤ IOP < 8mm Hg) and risk factors for developing hypotony were analyzed. At presentation, 9.3% of patients (7.1% of affected eyes) had hypotony. During a median follow-up of 5.3 years, the rate of developing hypotony and low IOP were 0.04 per eye-year (/EY; 95% confidence interval [CI]: 0.02/EY, 0.05/EY) and 0.06/EY (95% CI: 0.04/EY, 0.08/EY), respectively. Risk factors for development of hypotony during follow-up appeared to be associated with more severe uveitic disease, such as the presence of panuveitis (adjusted hazard ratio [aHR], 43.1; P= .004), anterior chamber cells or flare ≥ 3+ (aHR, 25.6, P < .001), posterior synechiae (aHR, 5.9, P= .02), and the use of oral corticosteroid (aHR 28.9; P= .003) at the presenting examination. Receiving immunosuppressive drug therapy at the time of presentation was associated with a lower risk of development of hypotony (aHR, 0.02; P= .002). Hypotony affects a small but significant proportion of patients with JIA-associated uveitis and is associated with signs of active and severe uveitis. Immunosuppression was associated with significantly lower risk of hypotony, suggesting that aggressive control of the inflammation may reduce risk of hypotony in JIA-associated uveitis.

Cryo-compression of sclerotomy sites after transconjunctival sutureless vitrectomy

Purpose: Transconjunctival sutureless vitrectomy(TSV) has become more commonly performed, but the incidence of sclerotomy site leakage is becoming an issue. We have developed a new and easy sclerotomy closure technique using cryotherapy, and named it ‘cryo-compression’.Methods: After the removal of the cannula, sclerotomy sites’ cryotherapy was performed with the setting of one cryospot for each site and ten seconds for each spot. After cryotherapy, firm pressure was maintained for more than 30 seconds. Immediately after compression, when any degree of leakage was detected, a single transconjunctival suture with 8-0 vicryl was placed. Postoperatively, topical steroid and antibiotics eyedrops were administrated.Results: Sixteen patients undergoing 23-gauge vitrectomy with this technique were reviewed retrospectively. The postoperative one- and six-hour intraocular pressures (IOPs) were significantly lower than preoperative IOP, but postoperative one-day and one-week IOPs were not different from preoperative IOP. Incidence of hypotony was 12.5% (N = 2/16 eyes) at only one hour but all eyes recovered. Intraoperative suture at sclerotomy sites was placed in eight of the 48 sclerotomies(16.7%) and suture placement was not required postoperatively. No cases of severe intraocular inflammation or endophthalmitis were indentified.Conclusions: Our short-term results are fairly respectable, so we think that the ‘Cryocompression’ technique is helpful to obtain sclerotomy closure in TSV.

Subconjunctival Versus Intrascleral Application Of Mitomycin C During Trabeculectomy.

Purpose: To compare efficacy and safety between subconjunctival and intrascleral methods of mitomycin C (MMC) application during trabeculectomy Methods: This retrospective study included 165 eyes treated by trabeculectomy and compared clinical outcomes between eyes that received subconjunctival MMC (Group 1, 80 eyes, 48.5%) and eyes that received intrascleral (Group 2, 85 eyes, 51.5%) MMC. Surgical success was defined as an intraocular pressure (IOP) of 6-21 mmHg with or without topical antiglaucoma medication use. Results: Mean IOP values were not significantly different between Group 1 and Group 2 (P > 0.05) until 2 weeks after surgery, while they differed significantly at 1, 3, 6, 12, and 24 months after surgery (P < 0.05). The mean number of antiglaucoma medications was 3.6 ± 0.6 and 3.5 ± 0.7, respectively, before surgery (P = 0.327) and 0.27 ± 0.32 and 0.10 ± 0.29, respectively, at 24 months after surgery (P = 0.001). The surgical success rate at 24 months was 86.25% and 94.12% in Groups 1 and 2, respectively (P = 0.041; log-rank test). Encysted blebs were observed in 17 and 8 patients in Groups 1 and 2 (P = 0.034), respectively, at 24 months. There was no statistically significant difference in the incidence of hypotony, choroidal detachment, conjunctival leakage, cataract and the rate of postoperative procedures between Groups 1 and 2 (P > 0.05). Conclusions: Compared to the subconjunctival method, the intrascleral method of MMC application can increase the long-term success of trabeculectomy without increasing the complication rate.

Flow Dynamics of the EX-PRESS® Glaucoma Filtration Device

Trabeculectomy has been the gold standard of glaucoma surgery for over 40 years, but the technique is imprecise and is associated with complications. Glaucoma filtration implants offer an alternative to trabeculectomy. The EX-PRESS® device is a miniature implant of which the standardized ostium allows a potentially more reproducible outflow by creating a constant diameter channel for fluid to drain out of the anterior chamber into the subconjunctival space. In clinical studies, the EX-PRESS device has demonstrated similar efficacy to trabeculectomy in terms of reduction of intraocular pressure, but with a lower incidence of hypotony and choroidal effusions, a result of its standardized ostium. Glaucoma patients require fewer postoperative interventions and less glaucoma medication after EX-PRESS device compared with trabeculectomy, and have faster visual recovery to their preoperative baseline compared with trabeculectomy.

Suturing pattern of the scleral incision affect the postoperative intraocular pressure after 23G vitrectomy

Objective To observe the relationship between the suturing patterns to close the scleral incision and postoperative intraocular pressure (IOP) in 23G minimally invasive vitrectomy.Methods Eighty eyes of 80 patients with vitreoretinal diseases,who were treated with primary 23G minimally invasive vitrectomy,were enrolled in this prospective clinical study.Patients with poor closed scleral incision which need suturing were excluded from this study.The corrected visual acuity ranged from hand movement to 0.2.The IOP ranged from 7.9 to 19.8 mm Hg (1 mm Hg=0.133 kPa),with the mean of (13.9±1.8)mm Hg.The eyes were randomly divided into three groups:group A (20 eyes),suturing all three scleral puncture after vitrectomy; group B (20 eyes),suturing only two upper scleral puncture,but not the lower infusion puncture after vitrectomy; group C (40 eyes),no suturing for all 3 scleral puncture after vitrectomy.All patients underwent 23G vitrectomy only.The corrected visual acuity and IOP were observed after surgery.Results The corrected visual acuity were 0.1 0.3,0.2-0.5,0.3-0.8 in one,seven and 14 days after surgery,respectively.No one in group A,B experienced hypotony in one,three,seven and 14 days after surgery.Thirteen (32.5％),five (12.5 ％),two eyes (5.0％) in group C experienced hypotony in one,three and seven days after surgery.Seven eyes (17.5％) experienced severe hypotony (＜5 mm Hg)in 14 day after surgery in group C.The difference was statistically significant compared the incidence of hypotony in group C with group A,B respectively at different time points after surgery (xx2 =16.82,P=0.007).The difference was statistically significant compared the incidence of hypotony in group C at different time points after surgery (x2 =11.64,P=0.003).The difference was no significant compared the IOP between group A and B at different time points after surgery (F=1.618,P=0.205).Compared the IOP of group C to group A and B,the difference was statistically significant in one and three days after vitrectomy (F=9.351,P=0.000); but not statistically significant in seven and 14 days after vitrectomy (F=0.460,P=0.633).Conclusions Whether or not suturing the scleral punctures is closely related to postoperative hypotony in 23G vitrectomy.Suturing only the two upper scleral punctures can reduce the occurrence of postoperative hypotony. Key words: Surgical procedures, minimally invasive/adverse effects; Vitrectomy; Ocular hypotension/prevention & control

Incidence of hypotony and sympathetic ophthalmia following trans‐scleral cyclophotocoagulation for glaucoma and a report of risk factors

To report the incidence and risk factors for hypotony and estimate the risk of sympathetic ophthalmia following diode laser trans-scleral cyclophotocoagulation (TSCPC). Retrospective study using data from a private tertiary glaucoma clinic and review of the literature. Seventy eyes of 70 patients with refractory glaucoma who received TSCPC treatment. Review of the records of consecutive patients who underwent TSCPC by a single ophthalmic surgeon and review of the literature. Hypotony (including phthisis bulbi), sympathetic ophthalmia. Seven eyes (10%; CI 5-19%) developed hypotony and included 4 eyes that developed phthisis. Higher total energy delivered during TSCPC treatment was associated with an increased risk of hypotony: eyes that developed hypotony received a mean total energy of 192.5 ± 73.2 joules, compared to a mean of 152.9 ± 83.2 joules in hypotony-free cases. The risk of sympathetic ophthalmia estimated from a review of the published literature and current series was one in 1512, or 0.07% (CI 0.03%-0.17%). Total laser energy is one of several risk factors that act in a sufficient component cause-model to produce hypotony in an individual patient. The small sample size precluded inference for other individual putative risk factors but titrating laser energy may help decrease the occurrence of hypotony. The risk of sympathetic ophthalmia calculated from the literature is likely an overestimate caused by publication bias.

Rate of Hypotony Following 25-Gauge Pars Plana Vitrectomy

To report the rates of hypotony after 25-gauge vitrectomy. A retrospective review of 111 consecutive cases was performed in patients undergoing transconjunctival 25-gauge pars plans vitrectomy with either air or gas as a tamponade agent. The primary outcome measure was postoperative intraocular pressure less than 5 mm Hg. A Wilcoxon rank-sum test was conducted to determine the statistical significance of continuous variables in association with rates of hypotony. The overall incidence of hypotony on postoperative day 1 was found to be 8.1%. The rate of hypotony was 16.7% in uveitis cases and 0% in routine macular surgery. The rate of hypotony in cases in which sutures were used was 41.7%, compared to 4% in cases in which sutures were not used (P = .001). Hypotony rates were significantly higher after 25-gauge transconjunctival pars plana vitrectomy in uveitis and some other conditions.

Incidence of postoperative hypotony in 25-gauge vitrectomy: oblique versus straight sclerotomies

ObjectiveTo compare the incidence of hypotony after oblique and straight sclerotomies in 25-gauge transconjunctival sutureless vitrectomy (TSV). DesignRetrospective, comparative, interventional case series. ParticipantsTwo hundred seventy-five eyes of 250 patients. MethodsWe reviewed 275 consecutive cases of 25-gauge TSV. Oblique incisions were performed on 141 eyes and straight incisions on 134 eyes. ResultsOn postoperative day 1, there was no significant difference in the incidence of hypotony (9.9% vs. 9.2%; p = 0.85) between oblique and straight incisions. The type of incision showed no statistical effect on hypotony in eyes filled with fluid (p = 0.91) or air-gas (p = 0.81). Hypotony was significantly reduced using air-gas endotamponade (4.8%) as compared to fluid-filled eyes (20.0%; p = 0.0001). ConclusionOblique incisions do not reduce the incidence of postoperative hypotony in fluid-filled eyes or with air-gas tamponade. Air-gas tamponade use results in a 4-fold reduction in the incidence of hypotony.

Early postoperative hypotony and risk factors after 23G sutureless microincisional vitrectomy

Objective To observe the incidence of hypotony and its risk factors in the early stage after 23-gauge sutureless microincisional vitrectomy.Methods A retrospective case series.Seventy patients (70 eyes) who had undergone 23-gauge sutureless microincisional vitrectomy were enrolled.There were 41 phakic eyes,29 eyes with intraocular lens; 68 eyes with a single surgical procedure and 2 eyes with a second surgical procedure; 34 eyes with BSS tamponade and 36 with gas tamponade.Intraocular pressure (IOP)was measured by non-contact tonometry.Hypotony was defined as an IOP of 5 mm Hg (1 mm Hg=0.133 kPa ) or less.The incidence of hypotony and other complications at postoperative day 1,3 and 7 were observed.The influence of age,sex,side of operation,type of tamponade,status of lens,surgical time on postoperative hypotony was analyzed.Results Hypotony was found in 8 eyes (11.4％) on postoperative day 1 and recovered spontaneously on postoperative day 3.There were no significant differences comparing age (t=1.12),sex (x2 =2.23) and side of operation (x2 =2.01) between patients with hypotony and those without it.The patients with hypotony suffered longer surgical time than that of those without hypotony (x2=5.48,P＜0.05).The incidence of hypotony in eyes with gas tamponade was significantly lower than that in eyes with BSS tamponade (x2=5.48,P＜0.05).The incidence of hypotony in eyes with phakic eyes was lower than that in eyes with intraocular lens (x2 =4.20,P＜0.05).Hypotony was encountered in the 2 re-operated eyes.Choriodal folds were encountered in 2 eyes,but there was no other complication in other eyes.Conclusions A transient hypotony occurs commonly in first 3 days after 23-gauge sutureless microincisional vitrectomy.Hypotony was significantly influenced by type of tamponade,reoperation and intraoperative lens status. Key words: Vitrectomy/adverse effects; Surgical procedures, minimally; Ocular hypotension/etiology; Risk factors

Selectively bonded polymeric glaucoma drainage device for reliable regulation of intraocular pressure

A novel glaucoma drainage device (GDD) using a polymeric micro check valve with no reverse flow is presented for the effective regulation of intraocular pressure (IOP). A significant functional improvement was achieved by reducing the possible incidence of hypotony, as the proposed GDD only drains aqueous humor at a certain cracking pressure or higher. The device consists of three biocompatible polymer layers: a top layer (cover), an intermediate layer (membrane), and a bottom layer (base plate with a cannula). All three layers, made of soft polydimethylsiloxane (PDMS), were bonded together to realize the thin GDDs. The bottom layer was selectively coated with chromium (Cr)/gold (Au) to prevent stiction between the valve seat and the valve orifice so that the device could show enhanced reliability in operation and high yield in production. Two types of polymeric devices were fabricated; one was a glaucoma drainage device for humans (GDDH) and the other was a glaucoma drainage device for animals (GDDA). From subsequent in vitro tests, the cracking pressures were 18.33 ± 0.66mmHg (mean ± standard deviation) for GDDH and 12.42mmHg for GDDA, both of which were very close to the corresponding normal IOPs. From in vivo tests of GDDA, the IOP of all implanted devices was properly regulated within the target pressure (10-15mmHg). The experimental results showed that the proposed polymeric GDD has high potential for use in the treatment of glaucoma disease in terms of its repeatability of the cracking pressure and patients' relief from post-operative discomfort.

Combined 25-Gauge Vitrectomy and Posterior Tube Shunt Placement for Advanced Glaucoma

To report the initial clinical outcomes of a combined procedure utilizing 25-gauge vitrectomy and posterior tube shunt placement in eyes with refractory glaucoma not amenable to standard treatment. Retrospective chart review. We included 10 eyes (10 consecutive adult patients, mean age 61 years) with advanced glaucoma and anterior segment abnormalities precluding tube placement in the anterior chamber who were treated with combined 25-gauge vitrectomy and posterior tube shunt placement. Records of consecutive patients were reviewed for demographics, etiology of glaucoma, preoperative clinical data (visual acuity, intraocular pressure, number of ocular antihypertensive medications), and postoperative outcome measures at predetermined time points. (1) Intraocular pressure (IOP) at 1, 2, 6, and 12 months postoperatively; (2) number of ocular antihypertensive medications needed at 12 months postoperatively; (3) visual acuity (VA) at 12 months postoperatively; and (4) incidence of hypotony, retinal detachment, endophthalmitis, and corneal decompensation. Preoperatively, mean IOP was 31 mmHg, and patients required a mean of 2.5 ocular antihypertensive medications. Mean IOP at 1, 2, 6, and 12 months postoperatively were 17.0, 16.1, 17.8, and 16.1 mmHg, respectively, and significantly lower than preoperative IOP (P < 0.005 at all time points). At 1 year postoperatively, 90% of patients had an IOP < 20 mmHg, and 50% of patients required ≤ 2 ocular antihypertensive medications. At 1 year postoperatively, VA was the same or improved in 70% of patients, and no worse than 1 Snellen line in any patient. Corneal edema developed in 2 patients. No patient developed hypotony or endophthalmitis. Combined 25-gauge vitrectomy and posterior tube shunt placement can be successful in lowering IOP in eyes with advanced glaucoma not amenable to other therapies.

Two‐step oblique incision during 25‐gauge vitrectomy reduces incidence of postoperative hypotony

The efficacy of a two-step, oblique incision procedure during 25-gauge vitrectomy on postoperative hypotony was evaluated by a retrospective, case-control study. The transconjunctival incision during 25-gauge vitrectomy was made in two steps: penetration with a microvitreoretinal blade followed by a penetrater instrument of a blunt trocar. The two-step procedure was performed on 89 eyes and with the conventional incision on 68 eyes. The incidence of hypotony (intraocular pressure <6 mmHg) on the first postoperative day and after 1 week and 1 month was compared. Hypotony was found in two eyes (2%) with the two-step method and 12 eyes (18%) with the conventional incision on the first postoperative day (P = 0.001, Fisher's exact probability test). The preoperative intraocular pressure was not significantly different in the two groups but was significantly higher in the two-step group than in the conventional method group on the first postoperative day (P = 0.001, Wilcoxon rank test). Twenty-five-gauge vitrectomy with two-step oblique incisions will reduce the incidence of postoperative hypotony on the first postoperative day.

Outcomes of primary phakic trabeculectomies without versus with 0.5- to 1-minute versus 3- to 5-minute mitomycin C

PURPOSE: To compare the intraocular pressure and hypotony outcomes of primary phakic trabeculectomies with no mitomycin C (MMC), shorter MMC, and longer MMC exposure. METHODS: We evaluated primary phakic trabeculectomies with no MMC (36 eyes of 36 patients), 0.5- to 1-minute MMC (50 eyes of 50 patients), and 3- to 5-minute MMC (38 eyes of 38 patients) at the concentration of 0.5 mg/ml. Successful trabeculectomy was defined as an intraocular pressure of 21 mm Hg or less without development of a marked visual acuity loss associated with prolonged hypotony (intraocular pressure < 6 mm Hg over 3 months) and without the need for additional surgery to control intraocular pressure or treat postoperative complications. RESULTS: The three groups were similar in demographics, preoperative intraocular pressure, and medical dependency. However, the incidence of hypotony during the postoperative periods of 3 to 12 months was significantly higher in the 3- to 5-minute MMC group ( P < .05, chi-square test). Severe visual acuity loss associated with hypotony was also more frequently found in the 3- to 5-minute MMC group than in the 0.5- to 1-minute ( P = .009, chi-square test) group or the control group ( P = .014, chi-square test). In addition, the success probabilities were significantly different among the three groups ( P = .001, Kaplan-Meier survival analysis with log-rank test) and were the highest in the 0.5- to 1-minute MMC group and the lowest in the 3- to 5-minute MMC group. CONCLUSION: Shorter application (0.5 to 1 minute) of MMC appears to be optimal for the successful outcome of primary phakic trabeculectomy compared with no MMC or longer application of MMC at a concentration of 0.5 mg/ml.

Hypotony Following Trabeculectomy

To determine the risk factors for development of postoperative hypotony and the effects of hypotony on the outcome of surgery in terms of intraocular pressure (IOP) control and final visual acuity in patients who underwent standard trabeculectomy, trabeculectomy with postoperative 5-fluorouracil injections, trabeculectomy with intraoperative mitomycin-C, or trabeculectomy with both antimetabolites. We retrospectively reviewed the outcome in 155 eyes of 155 patients who underwent standard trabeculectomy (n = 15), trabeculectomy with postoperative 5-fluorouracil injections (n = 81), trabeculectomy with intraoperative mitomycin-C (n = 55), or trabeculectomy with both antimetabolites (n = 4). Hypotony developed in 108 (69.6%) eyes (IOP < 6 mm Hg) at some point postoperatively; this was transient (< 14 days) in 75 eyes, and prolonged (> 14 days) in 33 eyes. The positive preoperative factors for the development of prolonged hypotony were young age, myopia, and preoperative use of carbonic anhydrase inhibitor. The mean age of patients in whom prolonged hypotony developed was 57.3 +/- 18.3 years (compare the mean age without prolonged hypotony, 65.3 +/- 14.5 years, p = 0.02). Sixteen of 33 (48%) patients in whom prolonged hypotony developed were myopic (p = 0.02), and 23 of 33 (70%) patients in whom prolonged hypotony developed used preoperative carbonic anhydrase inhibitor (p = 0.07). There was no difference in the incidence of hypotony between patients who received 5-fluorouracil and those who received mitomycin-C. Postoperative hypotony was associated with three types of postoperative complications: shallow anterior chamber, choroidal detachment, and hypotony maculopathy (p = 0.02, 0.000, and 0.05, respectively). Hypotony did not have any effect on the success of surgery in terms of IOP control, but did have an effect on the visual outcome. Fourteen of the 33 patients (42.4%) in whom prolonged hypotony developed had worse visual acuity (p = 0.002); of these cases, four were due to hypotony maculopathy.

PMMA Implants via Temporal Clear Corneal Incisions: Concern Replaces Confidence

OBJECTIVE: A prospective study to compare two methods of closure of long temporal clear corneal incisions used for implantation of PMMA lenses. STUDY DESIGN: Twenty-eight patients had their incisions closed by either suturing with 10-0 vicryl or hydration of the anterior lip of the corneal entry. SETTING: Private practice Vernon, B.C. Canada. Patients: Individuals presenting in a solo practitioners office for senile cataract surgery. OUTCOME MEASURES: Incidence of hypotony, posterior capsule tears, iris fray, astigmatic shift and bacterial infections. RESULTS: No hypotony was detected, posterior capsule tear and iris fray each occurred in two cases, astigmatic shift to against the rule in 50% of cases, bacterial infection of suture penetration site in two and endophthalmitis in one. CONCLUSIONS: Patients had less pain with hydration of the anterior lip of the incision but two stitch abscesses and one bacterial endophthalmitis led to abandonment of clear corneal incisions for PMMA lens implantation with replacement by temporal scleral tunnel incisions. Infected patients made excellent recoveries but three bacterial infections in twenty-eight procedures is an unacceptable incidence of such a potentially severe complication.

PRESSURE CUP STUDIES IN EYES WITH RETINAL DETACHMENT.

Introduction The abnormal intraocular pressures noted in eyes with retinal detachment have been the subject of both study and conjecture for almost a century.1,2Despite the incalculable time and effort already devoted to the subject, the relationship between retinal detachment and intraocular fluid dynamics has not been clarified. The clinical finding of hypotony in an eye with a recently detached retina is generally regarded as characteristic, but little attention has been paid to the degree of hypotony and its possible significance. Some authors have observed that the degree of hypotony is roughly proportional to the area of retina detached.3-6The incidence of hypotony has been reported to increase with the duration of the detachment.3,7On the other hand, eyes with retinas detached for several months have been found more likely to develop glaucoma after successful reattachment.8It has even been suggested by Smith that patients with