Medical control of intraocular pressure with brinzolamide 1% after phacoemulsification

Background: To compare the effectiveness of only 1 drop of topical brinzolamide 1% with dosing every 12 hours and with no ocular hypotensive medication following clear corneal phacoemulsification surgery.Methods: This prospective, randomized, double-blind study was composed of 60 eyes of 60 patients who underwent uneventful clear corneal phacoemulsification surgery under topical anesthesia. There were no intraoperative complications. Eyes were randomized to receive only 1 drop of topical brinzolamide 1% immediately after surgery, 1 drop of brinzolamide 1% every 12 (q12h) hours starting immediately after speculum removal, or no ocular hypotensive medication (control group). Intraocular pressure (IOP) was measured preoperatively and at 4 to 6 hours and 18 to 24 hours postoperatively by a Perkins tonometer.Results: Preoperative IOP was not significantly different among the 3 groups. IOPs of both the brinzolamide 1 drop group (p = 0.000) and the brinzolamide q12h group (p = 0.001) were significantly lower than those of the control group at 4 to 6 hours postoperatively. The same result was observed at 18 to 24 hours postoperatively in the brinzolamide q12h group (p = 0.001) but not the brinzolamide 1 drop group (p = 0.489). The brinzolamide q12h group had significantly lower IOP compared with the brinzolamide 1 drop group (p = 0.000) at 18 to 24 hours postoperatively. None of the eyes in the medication groups, but 1 eye (5%) in the control group, had postoperative IOP elevation ≥30 mm Hg at 4 to 6 hours; such an elevation was not encountered at postoperative 18 to 24 hours. Preoperative to postoperative IOP increase of >5 mm Hg at 4 to 6 hours postoperatively was seen in 4 (20%), 4 (20%), and 14 (70%) eyes in the brinzolamide 1 drop group, the brinzolamide q12h group, and the control group, respectively.Interpretation: The current study reveals that 1 drop of brinzolamide 1% is sufficient to control IOP within the first 4 to 6 hours following uneventful phacoemulsification, whereas 12-hour dosing is necessary for prolonged control of IOP.     

Can preoperative anterior chamber angle width predict magnitude of intraocular pressure change after cataract surgery?

Objective: To determine whether preoperative anterior chamberangle width,capturedbyanteriorsegment optical coherence tomography (AS-OCT), can be a predictor of intraocular pressure (IOP) change following cataract surgery.Design: Prospective comparative observational study.Participants: Fifty-three eyes of 53 patients awaiting cataract surgery were included.Methods: Measurement of anterior chamber angle width and IOP using AS-OCT and Goldmann’s applanation tonometry, respectively, were performed before and 6 months after phacoemulsification and intraocular lens implantation. Preoperative and postoperative measurements were compared using paired t test. The prediction rule defined success as ≥20% IOP reduction from the baseline preoperative IOP measurement. Multivariate regression analysis was performed to assess the association of postoperative IOP with independent variables, including age, sex, systemic hypertension, diabetes mellitus, glaucoma, and preoperative anterior chamber angle width.Results: Data were collected from 32 females and 21 males with visually significant cataract. Mean age was 73.3 (SD 8.2) years. Mean IOP dropped from 15.1 (SD 3.l)mm Hg to 12.8 (SD 2.5) mm Hg (p < 0.0001) after cataract extraction. Mean anterior chamber angle width increased from 24.7° (SD 7.1°) to 38.1° (SD 6.0°) after surgery (p < 0.001). Multivariate regression analysis did not identify preoperative variables to be significantly associated with ≥20% postoperative IOP reduction.Conclusions: Cataract surgery results in significant and sustained mean reductions in IOP and concurrent increases in anterior chamber angle width for a period of at least 6 months after surgery. However, measurements of the preoperative anterior chamber angle width did not predict the IOP-lowering effect of cataract surgery.     

Does the use of trypan blue during phacoemulsification affect the intraocular pressure?

Objective: The purpose of the study was to evaluate the effect of trypan blue on intraocular pressure (IOP) after small-incision cataract surgery.Design: Prospective, randomized study.Participants: Fifteen patients (30 eyes) with bilateral, dense, age-related cataracts.Methods: Patients with glaucoma, ocular hypertension, exfoliation, pigment dispersion syndrome, history of uveitis, recent use of topical or systemic steroids, and previous ocular surgery were excluded. The patients were randomly assigned to receive trypan blue during cataract surgery for enhancing capsulorrhexis in 1 of their eyes, while in the other eye, trypan blue was not used. Cataract surgery was performed in an identical fashion in both eyes, with a sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable intraocular lens. The same viscoelastic (sodium hyaluronate) was used in all cases and was thoroughly aspirated at the end of the procedure. All patients received a single dose of 250 mg acetazolamide 8 hours after surgery. No other antiglaucomatous agent was used during surgery or postoperatively. The intraocular pressure (IOP) was measured preoperatively and at 24 hours, 1 week, 1 month, and 3 months postoperatively.Results: IOP values were similar in both groups at all 4 postoperative measurements. There was no statistically significant difference in postoperative IOP values between the eyes in which trypan blue was used and the control eyes.Conclusions: The use of trypan blue during small-incision cataract surgery does not have any effect on IOP during the immediate and early postoperative period.     

Factors that influence intraocular pressure after cataract surgery in primary glaucoma

Objective: We sought to find predictive factors for favourable postoperative intraocular pressure (IOP) after cataract surgery in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).Study Design: Retrospective evaluation of patients who had undergone cataract surgery.Participants: Forty-eight patients with POAG and 48 patients with PACG.Methods: Various clinical factors were evaluated retrospectively in 96 patients. All patients had undergone standard 2.75-3.5 mm limbal incision cataract surgery. Clinical parameters in patients with successful postoperative IOP courses were compared with those in unsuccessful patients. Success was defined as an IOP between 6 and 21 mm Hg, with fewer antiglaucoma medications needed compared with before surgery, and no need of additional glaucoma surgery.Results: In POAG, eyes with a highest preoperative IOP of <31 mm Hg or those being treated with <3 antiglaucoma medications before surgery had a significantly higher probability of success. In PACG, the probability of success was significantly higher if the highest preoperative IOP was <42 mm Hg, the number of antiglaucoma medications before surgery was <3, or the areas of peripheral anterior synechiae were <4 clock hours.Conclusions: Primary small-incision cataract surgery using phacoemulsification and foldable intraocular lens implantation may be the procedure of choice in patients with medically controlled glaucoma and coexisting visually significant cataracts, considering the highest preoperative IOP and number of antiglaucoma medications in POAG and PACG, and the area of peripheral anterior synechiae in PACG.     

Phacoemulsification in patients with nanophthalmos

Objective: To evaluate phacoemulsification surgery and its possible risks in patients with nanophthalmos.Design: The surgical procedure, corneal diameter, keratometry, axial length, visual acuity, and intraoperative and postoperative complications were reviewed. Scleral thickness was determined by echography.Participants: 5 patients, 8 eyes.Methods: The results of cataract surgery in nanophthalmic eyes were reviewed. Inclusion criteria was based on a clinical diagnosis of nanophthalmos and ocular surgery for cataract. Nanophthalmos was diagnosed according to a shorter than average axial length (usually less than 20.0 mm), typically a shallow anterior chamber, hyperopia, and scleral thickening greater than 1.5 mm. The procedure was planned as phacoemulsification, and foldable acrylic PCIOL implantation via a clear corneal tunnel.Results: The procedure was planned as phacoemulsification. Six eyes had cataract extraction with posterior chamber intraocular lens implantation by phacoemulsification. It was necessary to change the procedure to extraca-psular cataract surgery in 2 cases because of uncontrolled shallowing of the anterior chamber. Postoperative trabeculectomy was needed in 1 eye, and Nd:YAG laser capsulotomy was performed on 4 eyes. No postoperative uveal effusion or infections were seen in any of the eyes. Complications included iritis with posterior synechia (n = 1), transient choroidal hemorrhage (n = 1), vitreous loss (n = 1), posterior capsule opacity (n = 4), and glaucoma (n = 1). In 1 case retinal detachment developed 3 weeks postoperatively. Prophylactic laser iridoplasty or iridotomy was not performed for surgery.Conclusions: Although phacoemulsification seems to be relatively safe in nanophthalmic patients without performing any prophylactic surgical procedure, surgeons need to be attentive of the challenges of working through them when performing phacoemulsification in these high-risk eyes. However, with careful preoperative evaluation and planning, complications can be avoided.     

A trial of topical prednisolone acetate before intravitreal triamcinolone acetonide decreases intraocular pressure spikes

Objective: To compare adverse intraocular pressure (IOP) spikes in patients receiving intravitreal triamcinolone acetonide (IVTA) in 2 cohorts: (i) patients who underwent a topical prednisolone acetate trial (PAT) without incurring a short-term IOP rise, and (ii) control patients who did not undergo a PAT.Design: Retrospective cohort study.Participants: Charts of all patients who underwent any intravitreal injection during the study period were reviewed (n = 1150).Methods: Patients in the PAT group received a 6-week course of prednisolone acetate 1% 4 times per day and had an IOP that did not rise above 25 mm Hg or above 8 mm Hg over the IOP in the contralateral eye. Patients undergoing a PAT and having a short-term IOP rise were not studied. Control patients did not receive a PAT. All patients received 12-20 mg of IVTA. Patients were followed for a minimum of 6 weeks and follow-up lasted for I year or until intraocular surgery or another IVTA injection was performed.Results: There were 97 patients in the PAT cohort and 75 control patients. Patients in the PAT cohort had a lower proportional rise between maximum IOP and baseline (43%) compared with controls (64%) (p = 0.035). Patients in the PAT group also had a lower risk of incurring a 40% (p = 0.05), 60% (p = 0.0I8), and 100% (p = 0.045) increase in maximum IOP (vs baseline) compared with controls and were less likely to require glaucoma filtration surgery (p = 0.035).Conclusions: Patients undergoing a PAT who did not have a subsequent short-term IOP rise had a lower risk of severe IOP spikes after IVTA compared with those patients receiving IVTA but not having undergone a PAT.     

Comparison of dynamic contour tonometry and Goldmann applanation tonometry following penetrating keratoplasty

Objective: To evaluate dynamic contour tonometry (DCT) versus Goldmann applanation tonometry (GAT) intraocular pressure (IOP) measurements in eyes that underwent penetrating keratoplasty (PKP).Design: Prospective, cross-sectional, observational study.Participants: Thirty-one eyes of 28 patients were examined after PKP.Methods: All eyes had undergone PKP with interrupted sutures. The postoperative period was more than 1 year for 25 eyes and less than 1 year for 6. Sutures were removed based on corneal topography and refraction. IOP was measured by both DCT and GAT methods and was correlated to the number of remaining sutures.Results: IOP readings were successfully obtained in 25/31 (80.6%) with DTC and in 21/31 (67.7%) with GAT (p = 0.25). In eyes with fewer than 4 remaining sutures, both methods were successful. In eyes with more than 4 sutures, the success rates of DCT and GAT were 66.7% and 44.4%, respectively (p = 0.18). In PKPs with a postoperative period of more than 1 year, the success rates of DCT and GAT were 96% and 84%, respectively (p = 0.16). In 20 eyes, both methods measured the IOP. The mean IOP obtained by DCT (16.6 [SD 2.8] mm Hg) was higher than the mean IOP obtained from GAT (15.1 [SD 3.6] mm Hg). The IOPs from the 2 instruments correlated significantly (p < 0.05) and the mean difference was 1.5 mm Hg.Conclusions: The success rate in measuring IOP with DCT and GAT did not show any statistically significant difference. Both methods were less effective measuring the IOP after recent PKPs and regrafts. However, DCT seemed to be superior to GAT in corneas with more than 4 remaining sutures and in PKPs performed more than 1 year earlier. The absolute values of IOP were higher with DCT than with GAT.     

Efficacy and safety of a steel drainage device implanted under a scleral flap

Objective: To evaluate the efficacy and safety of a stainless steel miniature glaucoma drainage device (Ex-PRESS X200) implanted under a scleral flap for the surgical treatment of primary open-angle glaucoma (POAG).Study Design: Clinical, prospective, noncomparative, nonrandomized study. The efficacy and safety were evaluated on the full sample, with a minimum follow-up of 12 months (maximum 24, mean 18).Participants: Thirty-seven eyes of 35 patients.Methods: The Ex-PRESS device was implanted under a scleral flap in patients with POAG.Results: Preoperative intraocular pressure (IOP) was 27.6 (SD 8.7) mm Hg; at last follow-up, IOP was 12.4 (SD 3.4) mm Hg (55.1% reduction). The success rates (IOP < 18 mm Hg and < 15 mm Hg at last visit without medications) were 78.4% (29/37) and 70.3% (26/37), respectively. Kaplan-Meier analyses (probability of IOP < 18 mm Hg and < 15 mm Hg without medications) at last follow-up were 72.6% and 47.9%, respectively. Early postoperative complications were clinically mild and included postoperative IOP < 5 mm Hg: 12 cases at 1 day, 8 cases at 1 week, 3 cases at 1 month, 1 case at 3 months; serous choroidal detachment: 9 cases, of which 3 spontaneously resolved, whereas in 6 cases, hypotony and flat chamber were treated with viscoelastic injection in the anterior chamber. At last follow-up, 6 patients were treated with 2 IOP-lowering medications. No sight-threatening consequences of surgery were observed. There were 8 cases (21.6%, n = 37) of bleb needling.Conclusions: Our data support the efficacy and safety of the implantation of this device under a scleral flap. The IOP reduction obtained was significant and long standing and complications were mild.     

Myopic shift after combined phacoemulsification and vitrectomy with gas tamponade

Background: Combination surgery of vitrectomy and phacoemulsification is a common procedure. The present study was undertaken to determine whether gas tamponade plays a role in the myopic shift that has been found previously after this type of surgery.Methods: The study compared 26 subjects undergoing combined procedures without gas tamponade and 28 subjects undergoing the same combined procedures with gas tamponade. The preoperative anticipated refraction was compared with the postoperative measured refraction.Results: The difference (Δ) between the predicted preoperative refraction and the resulting refractive status 2 months postoperatively was significantly different (t = 2.66, df = 48, p < 0.01) in eyes undergoing the combined procedure with gas tamponade (mean Δ = −0.30 D, SD = 0.66) compared with those eyes not receiving gas tamponade (mean Δ = 0.16 D,SD = 0.55). A difference in final refraction between the 2 groups of −0.46 D was found.Interpretation: Patients undergoing combined procedures with gas tamponade show a statistically significant myopic shift compared with those patients not receiving gas tamponade. Ophthalmologists performing combined procedures with gas tamponade should be aware of this shift in order to select the appropriate intraocular lens and to secure the best visual outcome postoperatively.     

Transconjunctival suturing of the scleral flap for overfiltration with hypotony maculopathy after trabeculectomy

Objective: To assess the efficacy of transconjunctival suturing of the scleral flap in improving hypotony maculopathy resulting from overfiltration after trabeculectomy.Design: Retrospective review.Participants: 35 eyes of 33 patients.Methods: Patients underwent transconjunctival scleral flap suturing for hypotony maculopathy following trabeculectomy using mitomycin C. The scleral flap was sutured through the conjunctiva as an outpatient clinic procedure using a spatulated needle with a 10-0 nylon suture.Results: The average age of the patients was 67.5 (SD 4.80, range 39-83) years, and 52% patients were male. The average duration of hypotony prior to transconjunctival suturing of the flap was 108.0 (SD 68.3) days. The median intraocular pressure (IOP) before suturing was 3 mm Hg, and the median IOP 6 months after the procedure was 9 mm Hg (p < 0.0001). The median best-corrected visual acuity (BCVA) before transconjunctival suturing of the scleral flap was 20/100, and the median BCVA 6 months after the procedure was 20/30 (p < 0.0001). Compared with visual acuity before suturing the average gain in BCVA was 4.9 (SD 0.8) lines.Conclusions: Transconjunctival suturing of the trabeculectomy scleral flap is an effective treatment to raise IOP and improve visual loss from hypotony maculopathy after trabeculectomy with overfiltering blebs.     

Delayed in-the-bag implantation of intraocular lens

Objective: To report delayed in-the-bag intraocular lens (IOL) implantation for patients who had undergone simultaneous phacoemulsification and vitreoretinal surgery.Design: Interventional case series.Participants: Delayed IOL implantation surgery was performed for 3 patients who had undergone simultaneous phacoemulsification and scleral buckling or vitrectomy surgery.Methods: The medical records of each patient, including the surgical findings and final refraction status, were reviewed retrospectively.Results: Successful in-the-bag IOL implantation surgeries without capsular tear were achieved 3 to 5 months after the initial surgeries. The postoperative refractive error ranged from plano to −1.00 D.Conclusions: Successful in-the-bag IOL implantation and satisfactory refraction were achieved in patients who had undergone simultaneous phacoemulsification and scleral buckling or vitrectomy surgery.     

Intravitreal bevacizumab and aqueous shunting surgery for neovascular glaucoma: safety and efficacy

Objective: To study the safety and efficacy of intravitreal injection of bevacizumab followed by aqueous shunting tube surgery for the management of neovascular glaucoma (NVG).Study Design: A prospective, non-randomized study with a historical control group.Participants: Twenty eyes of 20 patients with intractable NVG were treated with intravitreal injection of bevacizumab followed by aqueous shunting surgery (IVB group). A historical group of 10 NVG eyes treated with panretinal photocoagulation followed by aqueous shunting surgery without bevacizumab injection was used for comparison (PRP group).Methods: Injection of bevacizumab (1.25 mg/0.05 mL) was performed under topical anesthesia. An Ahmed valve was implanted in all cases after 1-2 weeks. In the IVB group, 10 eyes received postoperative panretinal photocoagulation (subgroup IA), and 10 eyes were followed without further photocoagulation (subgroup IB). Minimum follow-up was I year or when failure was diagnosed.Results: Mean preoperative intraocular pressure (IOP) was 46.5 mm Hg in the IVB group and 49.2 mm Hg in the PRP group (p = 0.5). After bevacizumab injection, iris neovessels regressed markedly. The final IOP after aqueous shunting tube surgery was 18.8 mm Hg in the IVB group and 15.9 mm Hg in the PRP group (p = 0.2). Postsurgical complications were comparable between the groups. The success rate was 85% and 70% in the 2 groups, respectively. Two eyes were considered failures, and 3 required repeated bevacizumab injections in subgroup IB as compared with I in subgroup IA.Conclusion: Intravitreal bevacizumab is a useful preparatory step to safely and effectively implant an aqueous shunting tube in NVG. Panretinal photocoagulation after bevacizumab injection promotes the success rate of aqueous shunt surgery by permanent ablation of the ischemic retina.     

Assessment of perceived difficulties by residents in performing routine steps in phacoemulsification surgery and in managing complications

Objective: To analyze the perceived difficulties of residents in performing the routine steps of phacoemulsification surgery and in managing complications.Design: Cross-sectional questionnaire-based study.Participants: Thirty-six residents performing phacoemulsification during their learning curve.Methods: On an 8-point Likert scale, residents noted comfort levels with various steps of cataract surgery and with managing complications.Results: The respondents were grouped into Group 1 (second-year residents, n = 19) and Group 2 (third-year residents, n = 17). Residents in Group 2 had greater surgical experience than residents in Group 1 (p = 0.001). The most difficult step in cases of phacoemulsification for Group 1 was loading a foldable intraocular lens (IOL) (mean score 6.05, SD 1.57), and for Group 2 it was nuclear emulsification (mean score 3.59, SD 1.42). Both second- and third-year residents found capsular bag dialysis the most difficult complication (mean scores 6.0 [SD 1.9] and 5.75 [SD 2.14], respectively). The second-year residents had significantly more difficulty with errant capsulorrhexis, anterior chamber IOL placement, and repeated iris prolapse as compared with third-year residents. Group 2 residents reported that mature, senile cataracts were the most difficult cases for them to manage (mean score 6.23, SD 1.56).Conclusions: This study identifies perceived difficulties that residents experience in routine cases of cataract surgery, highlighting specific areas in which they may benefit from additional training and practice.     

Investigating a possible cause of the myopic shift after combined cataract extraction, intraocular lens implantation, and vitrectomy for treatment of a macular hole

Objective: It has been documented that combination surgery (phacoemulsification, intraocular lens implantation, and vitrectomy) produces a postoperative myopic shift. We hypothesize that the myopic shift seen in patients treated with combination surgery, membrane stripping, and injection of C₃F₈ for treatment of a macular hole is due to an erroneously short preoperative axial length measurement by the IOLMaster.Study Design: Retrospective chart review.Participants: Eleven eyes of 10 patients treated for a stage III or IV macular hole were recruited from a database search of 1 vitreoretinal practice in Regina, Sask.Methods: All eyes included in the study underwent combination surgery, membrane stripping, and injection of C₃F₈. None of the patients demonstrated concurrent eye pathology. Postoperative axial length measurements by the IOLMaster were obtained and compared with the same preoperative measurements.Results: The mean (SD) postoperative myopic shift seen in the study eyes was −0.76 (0.65) D (z = −2.578, p < 0.01 ).The mean (SD) preoperative and postoperative axial length measurements were 23.54 (1.02) mm and 23.53 (1.01) mm, respectively. No significant difference in axial length was found between the preoperative and postoperative axial length measurements (t = 0.43, df = 10, p = 0.68).Conclusions: These findings do not support our hypothesis of an erroneous preoperative axial length measurement by the IOLMaster in patients with a stage III or IV macular hole treated with combination surgery, membrane stripping, and injection of C₃F₈. Further studies are required to determine the precise cause of the postoperative myopic shift.     

Inverse horse-shoe technique for the phacoemulsification of posterior polar cataract

Objective: To study a new technique of controlled hydrodelineation followed by viscodelineation and viscodissection during phacoemulsification in eyes with posterior polar cataracts and to report its effectiveness in preserving the posterior capsule.Design: Prospective interventional study.Participants: Twenty-eight eyes of 22 patients with posterior polar cataracts.Methods: All patients underwent phacoemulsification under topical anaesthesia with controlled hydrodelineation, viscodelineation, and viscodissection with minimal stress on the posterior capsule. Hydrodissection was not done. The preoperative complications and visual outcome were recorded.Results: The mean follow-up time was 8 months (range 2-24 months). Posterior capsule rupture occurred only in 2 eyes (7.1%); neither of the 2 had any vitreous prolapse, so anteriorvitrectomy was not required. Mean visual acuity improved significantly after surgery (p = 0.0001, paired t test). The causes of the low postoperative visual acuity were amblyopia in 3 eyes (10.7%) and age-related macular degeneration in 1 (3.6%).Conclusions: This inverse horse-shoe technique of controlled viscodelineation and viscodissection markedly reduced the risk of posterior capsule rupture. Moreover, if it occurred, the anterior vitreous face remained intact, so the IOL could be implanted in the sulcus without resorting to anterior vitrectomy.     

The effect of combined topical-intracameral anaesthesia on neuroleptic requirements during cataract surgery

Objective: To evaluate whether the addition of intracameral lidocaine to topical anaesthesia during cataract surgery leads to a decrease in the administration of intraoperative midazolam and fentanyl.Design: Retrospective case-control study.Participants: The eyes of 124 patients undergoing phacoemulsification were included in the study, with 62 in the intracameral group and 62 in the control group.Methods: A single-centre, retrospective chart review of cases between April and October 2007 in which patients had undergone small-incision phacoemulsification with foldable intraocular lens insertion and received preoperatively either topical tetracaine 0.5% with unpreserved intracameral lidocaine 1% (intracameral group) or topical tetracaine 0.5% alone (control group). Intraoperatively, midazolam and fentanyl were administered as needed based on pain and anxiety.Results: A total of 124 eyes (124 patients) were included. There was no statistically significant difference between the mean intraoperative midazolam doses given for the 2 groups (p = 0.08). The mean intraoperative dose of fentanyl was lower in the intracameral than in the control group (p < 0.0001). A comparison of intraoperative fentanyl requirements between groups using a multivariate regression analysis for age, gender, surgical time, and preopera-tive fentanyl levels confirmed the lower need for intraoperative fentanyl in the intracameral compared with the control group (p = 0.0037). There were no anaesthetic complications among any of the study patients.Conclusions: Patients receiving topical tetracaine 0.5% with unpreserved intracameral lidocaine 1% during cataract surgery demonstrated a reduction in intraoperative fentanyl requirements. Surgeons performing cataract surgery under topical anaesthesia should consider the addition of intracameral lidocaine 1% to decrease fentanyl requirements and improve patient safety and comfort.     

Posterior capsulectomy using a 25-gauge microincision vitrectomy system for preventing secondary opacification after congenital cataract surgery: outcome up to 4 years

Objective: To assess long-term outcomes of posterior capsulectomy using a 25-gauge microincision vitrectomy system (25-GV) for preventing secondary visual axis opacification after congenital cataract surgery.Study Design: Retrospective noncomparative case series.Participants: Nine eyes of 5 children who underwent posterior capsulectomy carried out with the use of a 25-GV during congenital cataract surgery.Methods: After removal of congenital cataract with phacoemulsification and intraocular lens implantation, the posterior capsulectomy was performed using a 25-GV. Postoperative visual outcomes were analyzed.Results: The mean follow-up period was 43.11 (SD 5.53) months. Eight eyes maintained a clear visual axis, but 1 eye required Nd:YAG capsulotomy to enlarge the opening of the capsulectomy at 7 months postoperatively. Postoperative visual acuity was maintained up to 4 years without any other complications.Conclusions: Posterior capsulectomy using a 25-GV offers an option for preventing secondary visual axis opacifica-tion after congenital cataract surgery.     

Intraocular pressure adjusted for central corneal thickness as a screening tool for open-angle glaucoma in an at-risk population

Objective: Evaluation of intraocular pressure (IOP) adjusted for central corneal thickness (CCT) screening for open-angle glaucoma (OAG) in an at-risk population.Study Design: Community-based screening clinic.Participants: Three hundred and forty-nine persons of black race, or >50 years of age, or with a positive family history of glaucoma.Methods: Ophthalmological examination including Goldmann applanation tonometry, ultrasonographic corneal pa-chymetry, and visual field testing. Glaucomatous optic nerve damage with visual field loss was the gold standard. IOP was adjusted for CCT based on 3 nomograms. Results were compared with screening using unadjusted IOP. Outcome measures included sensitivity, specificity, areas under the receiver operating characteristic (ROC) curves, positive and negative predictive values (PPVs and NPVs), as well as positive and negative likelihood ratios.Results: No significant difference in CCT was found between those with glaucoma (560 [SD 37] µm, n = 31) and those without (557 [SD 35] um, n = 233). Screening adjusted IOPs for glaucoma with an IOP > 21 mm Hg resulted in PPVs of 23.8% to 25% and NPVs of 89.3% to 89.6%, similar to preadjustment values. Areas under the ROC curves varied from 0.544 to 0.571 post adjustment from the initial value of 0.574.Conclusions: IOP adjusted for CCT is unlikely to improve tonometry as a screening tool for OAG in an at-risk population.     

Prediction of postoperative astigmatism in cataract surgery

Background: The purpose of this study was to predict postoperative astigmatism using refraction, keratometry, and other preoperative information after phacoemulsification with posterior chamber intraocular lens (IOL) implantation.Methods: A retrospective study was conducted of 176 eyes of 161 patients undergoing phacoemulsification for visually significant cataract with capsular bag or sulcus IOL fixation at the Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, Va. Eyes with complications and final-corrected visual acuity of less than 20/60 were excluded. Keratometric and refractive astigmatism were described by Jackson cross-cylinder with-the-rule (J₀) and oblique (J₄₅) components. Preoperative predictors of postoperative refractive J₀ and J₄₅ were determined by univariate and multivariate regression analysis.Results: The final multivariate model to predict postoperative with-the-rule astigmatism was J_{0Postoperative} = 0.24 × J_{0Preoperative} 0.46 × J_0Keratometic − 0.08 (coefficient of determination [r²] = 0.51, all p < 0.001). The multivariate model based on expected predictors of oblique astigmatism was J_{45Postoperative} = 0.10 × J_{45Preoperative} + 0.23 × J_{45Keratometric} + 0.01, (r² = 0.05, p = 0.09 for J_{45Preoperative} and 0.03 for J_{45Keratometric}). Temporal clear cornea (as opposed to superior scleral tunnel) incisions, and use of sutures in scleral tunnel incisions, were not predictive of postoperative astigmatism.Interpretation: Postoperative astigmatism can be estimated from preoperative astigmatism using the following weighted average: two-thirds keratometric and one-third refractive astigmatism. Preoperative refraction may predict postoperative astigmatism independent of keratometry because keratometry reflects only the paracentral anterior (not posterior) corneal curvature.     

Histological and clinical study of eyes with true exfoliation and a double-ring sign on the anterior lens capsule

Objective: To investigate the histological and clinical relation between eyes with true exfoliation (TEX) and a double-ring sign (DRS). Study Design: Retrospective clinical case study.Participants: Twenty-four eyes of 22 patients who underwent cataract surgery at Kochi Medical School Hospital and its affiliated hospitals during the period from April 1994 to September 2007.Methods: Twenty-four anterior lens capsules excised in cataract surgery underwent a histological examination and their clinical backgrounds were investigated. The TEX group consisted of 13 eyes with capsular delamination on the anterior lens capsule confirmed by slit-lamp microscopy before the surgery, and the DRS group consisted of 11 eyes that showed a double-ring sign during capsulorrhexis.Results: Twenty-two eyes underwent phacoemulsification and aspiration after uneventful capsulorrhexis. Two eyes that showed phacodonesis underwent extracapsular cataract extraction. In all specimens the capsular delamina-tion was confirmed. In some specimens from both groups, vesicle spaces were observed in the capsule and the underlying epithelium. In the TEX group, 8 eyes had capsular complications, such as pseudoexfoliation and phacodonesis, and in the DRS group, 2 eyes had phacodonesis (p = 0.016, student's t test).Conclusions: In spite of different clinical processes leading to capsular delamination, there were not any specific histological differences distinguishing the TEX group from the DRS group. The incidence of capsular complications was significantly higher in the TEX group than in the DRS group.