Early Intraocular Pressure Research Articles

Loss of Pressure Control Resulting from Tube Bending during Glaucoma Drainage Tube Perforations

Tube perforations are a common method of achieving early intraocular pressure control with ligated glaucoma drainage devices (GDDs). Our purpose was to investigate how bending GDD tubes affects the performance of needle perforations. Experimental report. Twenty silicone GDD tubes attached to 27 G Rycroft cannulae tied with 7-0 Vicryl 10 mm from the cannulae tips. Silicone GDD tubing was fitted over a 27 G Rycroft cannula and tied with a 7-0 suture 10 mm from the cannula tip. The tube was perforated 4 mm from the cannula tip with a 25 G needle (tube was kept straight). The tube was secured in a 50-mm water bath. Aqueous food dye was infused through the cannula from an adjustable height. The tube was observed under magnification while the height of the fluid column was adjusted to establish the pressure gradient at which the tube leaked dye (opening pressure) and ceased to leak (closing pressure), while the tube was held straight and bent 90 degrees. Measurements were repeated after a second perforation and a third perforation. Ten tubes were tested this way with 3 sequential slits. The entire experiment was repeated with another 10 tubes, but this time the tube was allowed to bend within the 3.5-mm open prongs of a needle holder during needle perforation. Opening and closing pressures. For each tube, the opening and closing pressures were similar and highly reproducible, but there was wide variation between tubes. In the tubes kept straight when perforated, the opening/closing pressure ranged from 5 to 25 cmH2O. The opening and closing pressures of slits made in the bent tube were significantly lower, frequently leaking at <1 cmH2O. Bending the tube after perforation could close a slit and prevent leakage at high perfusion pressure. The second and third successive perforations caused lower opening and closing pressures. Tube perforations behave like pressure-sensitive valves, opening whenever intraluminal pressure increases above a specific value. However, we found a large variation in the performance of fenestrations made with a 25-G hypodermic needle. Allowing the GDD tube to bend during needle perforation increases the risk of very low opening and closing pressures.

Early transient intraocular pressure spike after cataract surgery in highly myopic cataract eyes and associated risk factors

PurposeTo investigate the incidence of the early transient intraocular pressure (IOP) spike after cataract surgery in eyes with highly myopic cataract (HMC) and associated risk factors.MethodsConsecutive patients treated with phacoemulsification...

Efficacy and Safety of Repeated Ultrasound Cycloplasty Procedures in Patients With Early or Delayed Failure After a First Procedure.

Repeated ultrasound cycloplasty (UCP) procedures are valuable options in patients with early or delayed intraocular pressure (IOP) increase after a first procedure. The safety of a second procedure is similar to that of the first one. The purpose of this study was to evaluate the efficacy and safety of repeated UCPs in patients with early or delayed IOP increase after a first procedure. Thirty-one eyes with open-angle glaucoma, with an IOP decrease,>20% after a first UCP procedure (1 and/or 2 mo visit), and with an early or delayed IOP increase (IOP decrease<20% compared with baseline before or after the first 6 mo, respectively), underwent a second UCP procedure. Examinations were performed at 1 day, 1 week, 1, 2, 3, 6, and 12 months. Primary outcomes were surgical success (IOP reduction≥20% and IOP>5 mm Hg) at the last follow-up and vision-threatening complications. Secondary outcomes were mean IOP at each visit, medication use, and other surgical interventions. In the group with early IOP increase, IOP was reduced (P<0.05) from a mean value of 29.8±8.2 mm Hg before retreatment (n=3.3 medications) to 18.5±7.4 mm Hg at the last follow-up (n=3.5 medications) (-34%). Success was achieved in 52.6% of eyes (10/19) at the last follow-up visit. In the late IOP increase group, IOP was reduced (P<0.05) from a mean value of 31.9±6.6 mm Hg before retreatment (n=4.0 medications) to 16.2±5.2 mm Hg at the last follow-up (n=4.0 medications) (-43%). Success was achieved in 55.5% of eyes (5/9) at the last follow-up visit. No major intraoperative or postoperative complications occurred. A second UCP procedure could be considered in subjects with early or delayed failure after a first procedure.

Safety and efficacy of high-intensity focused ultrasound in severe or refractory glaucoma.

The aim of this study was to evaluate the efficacy and safety of ultrasonic cyclocoagulation in severe or refractory glaucoma, and to analyze the procedure-related inflammation. In this retrospective study, 15 eyes of 13 patients suffering from severe or refractory glaucoma with uncontrolled intraocular pressure of ⩾21 mmHg underwent 8-s ultrasonic cyclocoagulation. A complete ophthalmic evaluation, quality of life assessment using Glau-Qol-17, endothelial cell count, and flare measurement were performed. Primary outcome was qualified surgical success (defined as intraocular pressure reduction from baseline ⩾20% and intraocular pressure >5 mmHg without hypotensive medication adjunction). Secondary outcomes were flare, endothelial cell loss, and quality of life. Qualified success was achieved in 67% of eyes at 6 months (mean intraocular pressure reduction = 42% in these eyes). During the first month after the procedure, the mean flare reached its maximum value when the intraocular pressure was minimal; the flare slowly decreased until normalization at month 3 when the maximal intraocular pressure was noted. At month 3, there was moderate but significant endothelial cell loss (11%), and no significant alteration in quality of life was demonstrated. The efficacy of ultrasonic cyclocoagulation in the present study is comparable to that reported in the literature. The kinetics of intraocular pressure and flare suggest that postoperative inflammation could be partly responsible for the early intraocular pressure decrease. The moderate endothelial cell loss, which could be caused by localized heating, and the preservation of quality of life confirm the safety of ultrasonic cyclocoagulation.

Lentiviral Vector-Mediated Expression of Exoenzyme C3 Transferase Lowers Intraocular Pressure in Monkeys.

Primary open-angle glaucoma (POAG) is considered a lifelong disease characterized by optic nerve deterioration and visual field damage. Although the disease progression can usually be controlled by lowering the intraocular pressure (IOP), therapeutic effects of current approaches do not last long. Gene therapy could be a promising method for persistent treatment of the disease. Our previous study demonstrated that gene transfer of exoenzyme C3 transferase (C3) to the trabecular meshwork (TM) to inhibit Rho GTPase (Rho), the upstream signal molecule of Rho-associated kinase (ROCK), resulted in lowered IOP in normal rodent eyes. In the present study, we show that the lentiviral vector (LV)-mediated C3 expression inactivates RhoA in human TM cells by ADP ribosylation, resulting indisruption of the actin cytoskeleton and altered cell morphology. In addition, intracameral delivery of the C3 vector to monkey eyes leads to persistently lowered IOP without obvious signs of inflammation. This is the first report of using a vector to transduce the TM of an alive non-human primate with a gene that alters cellular machinery and physiology. Our results in non-human primates support that LV-mediated C3 expression in the TM may have therapeutic potential forglaucoma, the leading cause of irreversible blindness in humans.

Risk Factors for Early Intraocular Pressure Elevation After Cataract Surgery in a Cohort of United States Veterans.

Cataract surgery is the most frequently performed surgery in the Veterans Health Administration (VHA). A well-known complication is a transient but potentially harmful elevation in intraocular pressure (IOP) within the 24-h postoperative period. The purpose of this study is to investigate the risk factors for IOP elevation 1 d after cataract surgery in a cohort of United States (US) veterans. The study included 784 patients who underwent cataract surgery between April 2013 and April 2016 at a single Veterans Affairs medical center in Providence, RI. One thousand one hundred thirty-seven cataract surgeries were considered in total. Institutional Review Board (IRB) approval was obtained through the Providence Veterans Affairs Medical Center (PVAMC). Logistic regression, adjusted for patients with bilateral surgeries, was used to evaluate risk factors for first postoperative day IOP elevation (≥28 mmHg). The main outcome measure was elevated IOP on postoperative day 1 (POD1) after cataract surgery. The average patient age was 74 yr. Ninety-eight percent (1,110/1,137) of cases involved male patients; 75.3% (856/1,137) of the cataract surgeries were performed by resident surgeons. Type II diabetes mellitus (DM) was present in 41% (461/1,137), alpha-1 blocker use in 31% (358/1,137), ocular hypertension (ocular HTN) in 4% (44/1,137), and glaucoma in 11% (126/1,137) of cases. Twenty-two percent (232/1,137) of eyes had elevated IOP. Independent risk factors were a history of ocular HTN (OR: 8.74 [4.03-18.9]), glaucoma (OR: 3.54 [2.17-5.75]), a preoperative IOP ≥22 mmHg (OR: 2.51 [1.12-5.62]), and complicated cataract surgery (OR: 2.45 [1.18-5.08]), defined as vitreous loss, anterior capsular tear (ACT), posterior capsular tear (PCT), or presence of zonular lysis. These findings suggest that cataract surgery patients with ocular HTN, glaucoma, a preoperative IOP ≥22 mmHg, or significant intraocular complications may benefit from prophylactic ocular anti-hypertensive medication.

白内障超声乳化人工晶体植入术后早期眼压升高的原因分析

白内障超声乳化人工晶体植入术后早期眼压升高的原因分析

Perioperative medications for preventing temporarily increased intraocular pressure after laser trabeculoplasty.

Perioperative medications for preventing temporarily increased intraocular pressure after laser trabeculoplasty.

The role of day one postoperative review of intraocular pressure in modern vitrectomy surgery

BackgroundWith the introduction of sutureless 23-gauge (23G) vitrectomy, the risks for elevated intraocular pressure (IOP) and the need for day 1 review of IOP are less certain.AimsTo assess current practice...

Early Postoperative Intraocular Pressure Elevation after Vitreoretinal Surgery

Objective: The evaluation of intraocular pressure (IOP) after vitreoretinal surgery is critical to ensure the normal function of the eye. The purpose of this study was to determine the incidences and risk factors of early postoperative IOP elevation after vitreoretinal surgery. Method: Data were collected and retrospectively analyzed from 150 patients (150 eyes) who received vitreoretinal surgery from March 2012 to December 2012 in Tongji Hospital. IOP was measured before surgery and on day 1, 2, 3, 4-7 after surgery by Goldmann applanation tonometer. Ocular hypertension was defined as IOP ≥ 24 mmHg. The incidences and risk factors were analyzed. Results: 87 of the 150 patients were male and 63 were female. The IOP was elevated significantly in 54 eyes (36.00%) within 1 week after vitreoretinal surgery. Among them, 31 eyes (57.40%) occurred on day 1; 14 eyes (25.93%) occurred on day 2. The incidences of elevated IOP between different primary diseases had no statistical difference (p>0.05). However, patients with proliferative diabetic retinopathy (PDR), and rhegmatogenous retinal detachment (RRD) with proliferative vitreoretinopathy (PVR) grade ≥ C2, had higher rates of IOP elevation. Vitrectomy combined with cataract surgery or scleral buckling had no significant difference in IOP elevation compared with vitrectomy only (p>0.05). The rate of IOP elevation between 20G pars-plana vitrectomy (41.76%) and 23G pars-plana vitrectomy (27.40%) had statistical difference (p=0.033). The incidence of IOP elevation with intraocular tamponade of C3F8 was significantly higher than simple vitrectomy (chi2=7.723, p=0.005), while with silicone oil, the difference was not significant (chi2=3.627, p>0.05). Conclusion: IOP measurement after vitreoretinal surgery is important to monitor and prevent unintentional high IOP as it is a common complication after vitreoretinal surgery. The risk factors of early IOP elevation include the 20G pars-plana vitrectomy and C3F8 injection. Early treatment of IOP may prevent IOP spike to protect the vison.

Two-Year COMPASS Trial Results: Supraciliary Microstenting with Phacoemulsification in Patients with Open-Angle Glaucoma and Cataracts

We evaluated 2-year safety and efficacy of supraciliary microstenting (CyPass Micro-Stent; Transcend Medical, Inc., Menlo Park, CA) for treating mild-to-moderate primary open-angle glaucoma (POAG) in patients undergoing cataract surgery. Multicenter (24 US sites), interventional randomized clinical trial (RCT) (ClinicalTrials.gov identifier, NCT01085357). Subjects were enrolled beginning July 2011, with study completion in March 2015. Subjects had POAG with mean diurnal unmedicated intraocular pressure (IOP) 21-33 mmHg and were undergoing phacoemulsification cataract surgery. After completing cataract surgery, subjects were intraoperatively randomized to phacoemulsification only (control) or supraciliary microstenting with phacoemulsification (microstent) groups (1:3 ratio). Microstent implantation via an ab interno approach to the supraciliary space allowed concomitant cataract and glaucoma surgery. Outcome measures included percentage of subjects achieving ≥20% unmedicated diurnal IOP lowering versus baseline, mean IOP change and glaucoma medication use, and ocular adverse event (AE) incidence through 24 months. Of 505 subjects, 131 were randomized to the control group and 374 were randomized to the microstent group. Baseline mean IOPs in the control and microstent groups were similar: 24.5±3.0 and 24.4±2.8 mmHg, respectively (P > 0.05); mean medications were 1.3±1.0 and 1.4±0.9, respectively (P > 0.05). There was early and sustained IOP reduction, with 60% of controls versus 77% of microstent subjects achieving ≥20% unmedicated IOP lowering versus baseline at 24 months (P= 0.001; per-protocol analysis). Mean IOP reduction was ↓7.4 mmHg for the microstent group versus ↓5.4 mmHg in controls (P < 0.001), with 85% of microstent subjects not requiring IOPmedications at 24 months. Mean 24-month medication use was 67% lower in microstent subjects (P<0.001); 59% of control versus 85% of microstent subjects were medication free. Mean medication use in controls decreased from 1.3±1.0 drugs at baseline to 0.7±0.9 and 0.6±0.8 drugs at 12 and 24 months, respectively, and in the microstent group from 1.4±0.9 to 0.2±0.6 drugs at both 12 and 24 months (P < 0.001 for reductions in both groups at both follow-ups vs. baseline). No vision-threatening microstent-related AEs occurred. Visual acuity was high in both groups through 24 months; >98% of all subjects achieved 20/40 best-corrected visual acuity or better. This RCT demonstrated safe and sustained 2-year reduction in IOP and glaucoma medication use after microinterventional surgical treatment for mild-to-moderate POAG.

Icare ONE Home Tonometry in Children With and Without Known Glaucoma.

The Icare ONE (Finland Oy) rebound tonometer may have promise for home tonometry in children with glaucoma. The purpose of this study was: (1) to assess the feasibility of Icare ONE home tonometry in a small number of children with and without glaucoma and (2) to characterize diurnal intraocular pressure (IOP) variations in children with and without glaucoma. Patients were recruited from Duke pediatric ophthalmology clinic. Parents underwent in-clinic training for Icare ONE tonometry. Parents were instructed to record the subject's IOP using Icare ONE at 6 time intervals daily for 10 sequential days. Eight normal subjects (16 eyes) and 10 subjects (10 eyes) with glaucoma were included. All parents successfully performed Icare ONE home tonometry. In-clinic Icare ONE IOP exceeded Goldmann applanation in both groups. Normal subjects (mean age, 11.8 y) had a mean daily IOP range of 4.8 ± 4.6 mm Hg for right eyes and 5.2 ± 1.7 mm Hg for left eyes, and demonstrated relative peaks in the morning and relative troughs in the evening. Subjects with glaucoma (mean age, 12.4 y) had a mean daily IOP range of 8.6 ± 8.2 mm Hg, and demonstrated an even distribution of relative peaks and troughs throughout the day. Icare ONE home tonometry seems feasible in a small number of children. Normal eyes demonstrated smaller daily IOP ranges than glaucomatous eyes. Normal eyes were also more likely to show a relative early morning IOP peak and a late evening IOP trough. It is likely that the limited sampling in this study limits its generalizability to all children with glaucoma or to normal children.

Postural and diurnal fluctuations in intraocular pressure across the spectrum of glaucoma

AimsTo evaluate postural fluctuations (PFs) and diurnal variation (DV) of intraocular pressure (IOP) in patients with untreated glaucoma, glaucoma suspects and healthy volunteers, and study their relationship, if any, to...

Ab interno trabeculectomy: a comprehensive review

PURPOSE To summarize the original literature on ab interno trabeculectomy with the Trabectome system and to review its efficacy and safety in the treatment of glaucoma. METHOD A literature search in PubMed was performed on ab interno trabeculectomy with the Trabectome system, and clinical relevant information was reviewed and summarized. RESULTS Ab interno trabeculectomy with the Trabectome system on average lowered intraocular pressure (IOP) to the mid-teens, and decreased the number of required glaucoma medications. Greater preoperative IOP correlated to a greater percent reduction in IOP. The success rates varied among studies, and the definition of success differed by authors. Intraoperative blood reflux was found in nearly all cases. Incidences of early hypotony and IOP spikes were low. No cases of endophthalmitis, wound leak, aqueous misdirection, choroidal hemorrhage or effusions, and irreversible visual acuity decrease ( ≥ 2 Snellen lines) have been reported. Available studies had a significant amount of data overlap. Only limited data on long-term results was available. There was no randomized controlled trial to date. CONCLUSIONS Ab interno trabeculectomy with the Trabectome system is an effective and safe surgical approach for patients with various types of open angle glaucoma. On average, the procedure at least in the short term lowers IOP to the mid teens regardless of preoperative IOP with or without the aid of topical medications.

Early postoperative safety and surgical outcomes after implantation of a suprachoroidal micro-stent for the treatment of open-angle glaucoma concomitant with cataract surgery

To evaluate the safety of a new suprachoroidal device, the Cypass micro-stent, for the surgical treatment of open-angle glaucoma (OAG) implanted in conjunction with cataract surgery. Multicenter clinical study. Prospective interventional case series. This is an interim report of an ongoing safety study. Patients with OAG glaucoma (Shaffer grade 3 and 4) who were also candidates for cataract surgery in the affected eye had standard phacoemulsification followed by micro-stent implantation in the supraciliary space. Included were patients with uncontrolled (≥ 21 mm Hg, Cohort 1) or controlled (<21 mm Hg, Cohort 2) medicated intraocular pressure (IOP) at baseline. Glaucoma medications were discontinued at surgery and resumed at the discretion of each investigator. Measures included adverse events/complications and postoperative changes in IOP or medication. The mean baseline medicated IOP was 21.1 mm Hg ± 5.91 (SD); the mean number of IOP-lowering medications was 2.1 ± 1.1 (N = 184). There were no major events such as retinal or choroidal detachment or endophthalmitis. The most common complications were transient early hypotony (13.8%) and transient IOP increase (10.5%). Uncontrolled patients (n = 57) had a 37% IOP reduction (P<.001), with more than a 50% reduction in glaucoma medications at 6 months (P<.001). Intraocular pressure-controlled patients (n = 41) had a 71.4% reduction in glaucoma medications (P<.001). Initial clinical experience with the new micro-stent showed a low rate of surgical complications with concomitant decreases in IOP and/or glaucoma medications.

Effect of Dorzolamide/Timolol or Brinzolamide/Timolol Prophylaxis on Intravitreal Anti-VEGF Injection-Induced Intraocular Hypertension

ABSTRACTPurpose: To evaluate prospectively whether anti-glaucomatic drugs administered prior to intravitreal anti-vascular endothelial growth factor (VEGF) injection bevacizumab (Avastin,® Roche) or ranibizumab (Lucentis,® Novartis) prevents intraocular hypertension after the injection. Subjects and methods: In total, 166 patients (175 eyes) scheduled for intravitreal anti-VEGF injection treatment were prophylactically treated 1 hour before the procedure with Dorzolamide/Timolol (Cosopt,® MSD) (Group 1, 53 eyes) or Brinzolamide/Timolol (Elazop,® Alcon) (Group 2, 84 eyes) or left untreated (Group 3, 29 eyes). Intraocular pressure was analyzed 5 minutes prior to the injection, every 5 minutes for 30 minutes after the procedure, and 1 hour, 1 day, 7 days, and 1 month after the procedure. Results: The intraocular pressures 5 minutes before the procedure (baseline) for Groups 1, 2, and 3 were 12.06 ± 1.85, 13.98 ± 2.68, and 13.81 ± 2.24 mmHg, respectively. Five and 30 minutes after the procedure, the intraocular pressures of the three groups were 14.12 ± 4.18, 14.87 ± 3.35, and 28.21 ± 3.16 mmHg, respectively, and 10.87 ± 1.58, 14.25 ± 2.43, and 17.48 ± 2.34 mmHg, respectively. For all three groups, the changes relative to baseline 5 and 30 minutes after injection were significant. When the three groups were divided according to whether they received bevacizumab or ranibizumab and the changes in intraocular pressure relative to baseline were analyzed, all six subgroups exhibited significant changes in intraocular pressure 5 and 30 minutes after the procedure. Conclusion: The prophylactic administration of anti-glaucomatic drugs prior to intravitreal anti-VEGF injection effectively reduced the early intraocular pressure elevation. This approach was also safe and could be performed accurately.

Can early postoperative intraocular pressure predict success following mitomycin-C augmented trabeculectomy in primary angle-closure glaucoma

To evaluate the association between early and late postoperative intraocular pressure (IOP) and determine if early postoperative IOP can predict the surgical outcome. A total of 165 consecutive patients with primary angle-closure glaucoma (PACG) undergoing primary mitomycin-C-augmented trabeculectomy underwent a comprehensive eye examination before surgery and were followed-up on days 1, 7, 14, and 30, and months 3, 6, 12, and 18. IOPs on days 1, 7, 14, and 30 were stratified into groups A (<10 mm Hg), B (≥10 and <15 mm Hg), C (≥15 and <20 mm Hg), and D (≥20 mm Hg). Differences between groups were analyzed using analysis of variance (ANOVA) and Fisher's exact test. Multivariable regression was used to exam the predictive ability of early IOP for final outcome. The mean age was 62.5±7.9 years and 41.21% (n=68) were males. Stratified by IOP on days 1, 7, 14, and 30, respectively, mean IOPs at month 18 were different among groups A, B, C, and D (ANOVA, P=0.047, P=0.033, P=0.008, and P<0.001, respectively). Once the IOPs were settled with interventions on day 7 a higher IOP level was associated with decreasing success rate under different outcome definitions, final IOP <15 mm Hg (Fisher's exact P=0.001) and <20 mm Hg (P=0.039) without medication. Multiple regression showed early IOP predicted final IOP independently from baseline variables. A cutoff value of 13.5 mm Hg on day 7 achieved an accuracy of 80.0 and 57.1% in predicting IOP<15 mm Hg without medication and failure after surgery, respectively. The IOP at 18 months following primary antifibrotic-augmented trabeculectomy in PACG patients is associated with and predicted by the postoperative IOPs at 1 month. Control of early IOP to 13.5 or less may provide better outcomes.

Intraocular pressure elevation during early postoperative period after secondary intraocular lens implantation in children and adolescents

To look at the intraocular pressure (IOP) spike in the early postoperative period after secondary intraocular lens (IOL) implantation in children. Miles Center for Pediatric Ophthalmology, Medical University of South Carolina, South Carolina, USA. Retrospective chart review. The postoperative day-1 examination of patients having secondary IOL implantation by the same surgeon was reviewed for an IOP greater than 26 mm Hg. In patients with an IOP spike, the medical history and examination findings that might be associated with the rise were evaluated. Review of 85 patient charts (133 eyes) identified 9 eyes that developed an IOP spike during the early postoperative period. Six eyes were symptomatic, with symptoms including pain, ocular discomfort, nausea, and emesis, and 6 eyes had preoperative aphakic glaucoma, which was controlled with medication. Six of 22 eyes (27%) with preoperative aphakic glaucoma and 3 of 111 eyes (3%) without glaucoma (P<.001) developed an acute IOP rise (relative risk, 10.1). The high incidence of a symptomatic early IOP spike in patients with aphakic glaucoma warrants meticulous ophthalmic viscosurgical device removal at the end of surgery, consideration of the routine use of prophylactic topical and/or systemic glaucoma medication, and monitoring during the early postoperative period.

First postoperative day intraocular pressure rise in resident-performed cataract surgery

Sir, We read the article by Kim et al1 with interest and would like to highlight some concerns regarding their data and conclusions. The title and purpose of the study seems to indicate outcomes for a particular surgeon group (residents in training); however, the conclusions are not supported by the data. Amongst 1582 procedures, after excluding surgery complicated with vitreous loss, 305/1582 procedures were performed by attending surgeons and further excluded from analysis. The outcomes of these 305 surgeries is reported in the discussion as having an incidence of first postoperative day intraocular pressure (IOP) elevation no higher than the trainee-performed surgery (P=0.94, χ2-test). The authors have surprisingly chosen to present the study as a consecutive case series instead of a more useful comparative study. There is a discrepancy in the use of ophthalmic viscosurgical device (OVD). The methodology states use of two agents: Healon (1% sodium hyaluronate) initially in 2001 to 2005 and thereafter Duovisc, which is composed of two OVDs, the cohesive Provisc (1% sodium hyaluronate) and dispersive Viscoat (sodium chondroitin sulphate 4%–sodium hyaluronate 4%). However, in Table 2 the OVD reported as used is Healon GV, a hyaluronic acid product with a 10-times higher viscosity than Healon, preferred in complicated procedures (vitreous pressure, flat anterior chamber, so on) and thus probably chosen for resident surgery. The effect of OVDs with higher molecular weight and viscosity on postoperative IOP is well documented.2, 3 This may well explain the reason for this case series having a higher postoperative IOP 24 h after cataract surgery (22%, >23 mm Hg and 14.9%, >26 mm Hg) than the previously reported values of 2.57%4 and 11.8%,5 respectively. The effect of trainee surgeons on early IOP rise after cataract surgery can be a consequence of relatively more manipulations, residual OVD, and subsequent increased inflammation. This hypothesis maybe better supported by data on central corneal thickness, aqueous flare, surgery duration, phacoemulsification power etc as well as a comparative case–control study design.

The Effect of Early Posttrabeculectomy Intraocular Pressure Spike in the Collaborative Initial Glaucoma Treatment Study

To examine effects of early postoperative intraocular pressure (IOP) spike in patients undergoing primary trabeculectomy in the Collaborative Initial Glaucoma Treatment Study. We identified patients with IOP spike ≥5 mm Hg above the baseline IOP on postoperative day 1 and those without IOP increase. The mean deviation (MD), pattern standard deviation (PSD), and corrected PSD of the visual field (VF) were compared at 6 months and years 1, 2, 3, and 5 after surgery, as was the IOP. Seventeen of 300 patients (5.7%) had IOP spike. After controlling for baseline VF severity in a generalized linear regression model that addressed change in MD, PSD, and corrected PSD, or in a logistic regression model for ≥3 dB of MD change, comparison between the groups revealed no significant difference at all time points examined (P>0.05). Patients with IOP spike had significantly higher mean IOP at years 3 and 5 of follow-up (P≤0.04). Among Collaborative Initial Glaucoma Treatment Study patients, early posttrabeculectomy IOP spike ≥5 mm Hg above baseline IOP was not associated with subsequent VF loss, but was associated with significantly higher IOP during long-term follow-up.