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.     

A comparison of Scheimpflug imaging simulated and Holladay equivalent keratometry values with partial coherence interferometry keratometry measurements in phakic eyes

Objective: To evaluate the interchangeability of a Scheimpflug camera (Pentacam, Oculus) and a partial coherence interferometry keratometer (IOLMaster, Zeiss) for measures of keratometry and anterior chamber depth (ACD). A particular focus was to determine which Pentacam keratometry value best correlates with the IOLMaster and if these results can be used interchangeably in clinical practice.Study Design: Retrospective comparative study using data from the GRMC Vision Centre and ImagePlus Laser Eye Centre.Participants: Fifty-two eyes from 27 patients (11 male, 16 female) of normal general health with no history of ocular disease.Methods: Each eye was assessed by an IOLMaster as part of a complete eye examination, and later by the Pentacam, prior to laser in situ keratomileusis (LASIK) surgery.Results: The differences in the mean keratometry readings of the IOLMaster and those of the simulated and equivalent Pentacam measurements were 0.35 D and 0.23 D, respectively. The Bland-Altman plots showed 95% limits of agreement (LOA) of 0.92 D and 1.68 D for the same parameters. A comparison of ACD measurements revealed a 0.03 mm difference in mean measurements with a 95% LOA of 0.33 mm.Conclusions: The interdevice variability was significantly lower than that reported previously but still warrants caution if the 2 instruments are to be used interchangeably. With an appropriate correction for mean differences, the Pentacam's simulated keratometry values would be within 0.46 D of the IOLMaster, 95% of the time. When the Holladay equivalent keratometry values were compared with the IOLMaster, a greater interdevice variability was seen.     

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.     

Nerve fibre layer changes in highly myopic eyes by optical coherence tomography

Objective: The purpose of this study was to investigate any correlations that may exist between retinal nerve fibre layer (RNFL) thickness and high myopia by optical coherence tomography (OCT).Design: Case-control study.Participants: Ten patients (20 eyes) with high myopia and 10 control patients (20 eyes) matched for age and sex were recruited from a database search of 1 vitreoretinal practice in Regina, Sask.Methods: The RNFL thickness of 10 highly myopic patients and 10 control patients matched for age and sex from a clinical practice was determined using the Stratus OCT. All 10 highly myopic patients selected for the study had a spherical equivalent of ≥−10.0 D OU and an intraocular pressure <21 mm Hg OU, and failed to display glaucomatous changes such as disc hemorrhages and glaucomatous cupping in either eye. None of the patients included in the study had evidence of concomitant ophthalmic disease and none had had previous refractive surgery. Axial length measurements were done on all patients using the IOL Master.Results: The mean (SD) RNFL thicknesses in the control and myopic groups were 108.8 (10.6) μm and 80.0 (18.6) μm, respectively, with t = 6.0 and p − 0.001. A negative correlation of −0.712 with p < 0.001 was found between RNFL thickness and axial length.Conclusions: When interpreting the RNFL thickness of highly myopic patients by OCT, careful attention must be given to the inherently thinner RNFL to avoid a false glaucoma diagnosis.     

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.     

Acquired restrictive strabismus and high axial myopia: diagnosis and management

Objective: This paper documents the clinical, ultrasound, magnetic resonance imaging (MRI), and anatomic characteristics of 6 patients with esohypotropia and high axial myopia. The results of strabismus surgery performed on these patients are evaluated.Study Design: Retrospective cohort study.Participants: Six patients with esohypotropia and high axial myopia were selected from the practice of the second author (Michael Flanders).Methods: We extracted the history and data from the preoperative and postoperative ophthalmic and orthoptic examinations, recorded the surgical procedures, and tabulated the postoperative results. A- and B-scans, orbital MRI images, and photo documentation were obtained for all patients. Supramaximal recession and resection on the horizontal rectus muscles, using adjustable sutures, was performed in all patients. A surgical outcome was deemed successful if, in primary position, postoperative horizontal ocular alignment measured 15 prism diopters (PD) or less and (or) if diplopia was eliminated.Results: Echographic and MRI findings demonstrated an enlarged globe in all cases. Globe flattening on the orbital walls was found in 5 cases. Lateral rectus depression was visualized on MRI images in 4 cases. Surgical success was obtained in all patients. The average preoperative primary position esotropia measured 60 PD (25 to 90 PD) and the esodeviation after surgery was 7.0 PD (0 to 15 PD). Ductions were also improved.Conclusions: Different surgical approaches to realignment of eyes with high myopia and esohypotropia have been attempted. In this study, supramaximal amounts of recession and resection on the rectus muscles provided satisfactory results.     

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.     

Effect of the shape of the endothelial graft on the refractive results after Descemet's stripping with automated endothelial keratoplasty

Objective: To investigate the magnitude and the possible causes of the refractive changes after Descemets stripping with automated endothelial keratoplasty (DSAEK). In this article we describe the changes in corneal power after DSAEK and correlate them with the shape, diameter, and thickness of the endothelial graft obtained.Study Design: Retrospective chart review.Participants: 17 consecutive patients who underwent DSAEK at the Rand Eye Institute in 2007.Methods: The preoperative and post-DSAEK corneal power was determined using Gaussian optics and correlated with the DSAEK graft diameter and central, paracentral (P1), and peripheral (P2) graft thickness using images obtained from the Pentacam Scheimpflug.Results: During DSAEK there is addition of corneal tissue in the posterior layers of the cornea, which reduces the radius of curvature of the posterior layer of the cornea and also the total corneal power. The mean anterioposterior corneal radius of curvature ratio after DSAEK is 72.3% (SD 4.63%). In consequence, the keratometry values calculated after DSAEK using the Gaussian optics method are less than those measured by manual keratometry after surgery. A strong correlation was observed between the postoperative Gaussian keratometric power and the ratio of the central corneal DSAEK graft thickness (C) to the mean P2 measured at 7 mm optical zone (C:P2) (r² = 0.63, p < 0.01 ).Conclusions: DSAEK induced a mean hyperopic shift of 1.05 (SD 0.76) D. The mean anterioposterior corneal radius of curvature ratio decreased to 72.3%. Despite a great variability, the ratio between the central DSAEK graft thickness and the graft thickness at the 7 mm optical zone (C:P2 ratio) was correlated with the magnitude of the change in corneal power and induced hyperopia, which produces a steeper posterior corneal surface. No correlation between the DSAEK graft diameter and change in corneal power was noted. Customization in the shape of the donor graft lenticle might reduce the hyperopic shift noted after DSAEK.     

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.     

Changes in wave-front aberrations after rigid gas permeable contact lens fitting in post—laser in situ keratomileusis patients with visual complaints

Objective: To evaluate the effect of rigid gas permeable (RGP) contact lenses in reducing wave-front aberrations in post-laser in situ keratomileusis (LASIK) myopic patients.Design: Cross-sectional study.Participants: Thirty patients with visual complaints after conventional LASIK procedure for correcting myopia.Methods: The 30 patients were fitted with RGP contact lenses. Wave-front measurements were taken before and after RGP contact lens wearing.Results: Compared with bare eye examinations, root mean-square values of higher-order aberrations (HOAs) significantly decreased with RGP contact lens use. Amongthese, spherical aberration decreased from 0.507 (SD 0.304) μm to 0.164 (SD 0.121) μm(t = 7.186, p < 0.001); coma decreased from 0.470 (SD 0.312) μm to 0.165 (SD 0.090) μm (t = 5.566, p < 0.001); secondary coma decreased from 0.079 (SD 0.050) μm to 0.044 (SD 0.027) μm (t = 4.118, p < 0.001); and total HOAs decreased from 0.782 (SD 0.449) μm to 0.307 (SD 0.140) μm (t = 6.710, p < 0.001).Conclusions: Fitting RGP contact lenses effectively decreased HOAs induced by conventional myopic LASIK surgery. Possible reasons may be the elimination of irregularity and dissymmetry on the corneal anteriorsurface, relief of the aspherical extent of the central corneal surface, and enlargement of the effective optical zone.     

A Nontraumatic Macular Hole in a 10-Year-Old Girl

Background

Full-thickness macular holes usually develop in the elderly population. To the best of our knowledge, there has been no written report of a nontraumatic macular hole in a pediatric patient.

Case

A 10-year-old girl noticed decreased central vision in her left eye without any history of trauma.

Observations

Fundus examination of the left eye revealed a full-thickness macular hole and a thin fibrous membrane on the superior peripapillary retina. She underwent standard macular hole surgery with stripping of the membrane, resulting in closure of the hole.

Conclusions

A full-thickness macular hole may develop in pediatric patients. Although the etiology of the macular hole in the present patient is unclear, tangential traction induced by contraction of the peripapillary membrane, presumed to be an incomplete regression of the Bergmeister papilla, might have been responsible for the formation of the macular hole. Jpn J Ophthalmol 2005;49:520–522© Japanese Ophthalmological Society 2005     

Comparison of the outcome of implantation of hydrophobic acrylic versus silicone intraocular lenses in pediatric cataract: prospective randomized study

Objective: To compare the postoperative performance of hydrophobic acrylic and silicone square-edge intraocular lenses in pediatric cataract.Design: Prospective randomized study.Participants: Forty-one eyes of 41 children (age 1 month to 8 years) with congenital or developmental cataract.Methods: Children were randomly divided into 2 groups. All participants underwent phacoaspiration, primary posterior capsulotomy, and anterior vitrectomy. Group A (n = 21) eyes were implanted with acrylic hydrophobic AcrySof SA60AT intraocular lenses (IOLs), and those of Group B (n = 20) were implanted with silicone Tecnis Z9000 IOLs. The children were evaluated for anterior chamber reaction, IOL position, posterior capsular opacifica-tion (PCO), intraocular pressure, best-corrected visual acuity (BCVA), corneal status, and refractive errors.Results: Postoperatively, 2 eyes in each group had significant anterior chamber reaction with fibrin membrane formation. IOLs were in the capsular bag in all but 1 eye in both groups. Seven eyes in the acrylic group and 6 eyes in the silicone group achieved visual acuity of 20/40 or better. None of the eyes showed glaucoma. BCVA at 1 year was similar in both groups. In the acrylic hydrophobic group, 14 eyes needed hypermetropic correction and 7 eyes were myopic, and in the silicone group 10 eyes had myopia and 10 eyes had hypermetropia at 1 year postoperatively. PCO at 1 yearfollow-up was more common in eyes implanted with acrylic hydrophobic IOLs (5 eyes) than silicone IOLs (2 eyes).Conclusions: Both square-edge hydrophobic acrylic and silicone IOLs were found to be compatible and safe for use in pediatric cataract surgery with similar visual axis clarity and postoperative outcome.     

Anatomical and visual outcomes in high myopic macular hole (HM-MH) without retinal detachment: a review

Purpose

To review postoperative anatomical and functional outcomes in high myopic macular hole (HM-MH) without retinal detachment.

Methods

In the PubMed database, published articles on myopic macular hole surgery from 2000 to 2013 (present days) were reviewed. Inclusion criteria were high myopia and macular hole (MH). Series with posterior retinal detachment secondary to MH and myopic foveoschisis (MFS) without MH were excluded. Main outcomes included MH closure rate, resolution of the foveoschisis, if present, and postoperative visual acuity. Optical coherence tomography (OCT) features and postoperative evolution were also evaluated when reported.

Results

A total of 131 articles were initially found. After having applied the exclusion criteria, 15 articles were reviewed. Four were focused on HM-MH with concomitant foveoschisis (Schisis Group), and ten included only HM-MH without FS case series (Flat Group). Only one comparative study between these two groups was found. Surgical techniques were observed to be similar for both groups in most series, including vitrectomy with or without internal limiting membrane (ILM) removal, and gas or silicone oil tamponade. However, in one retrospective study, macular buckling was applied together with pars plana vitrectomy in cases of HM-MH with foveoschisis. When available, preoperative and postoperative OCT provided a useful evaluation of the status of the macula. Different prognosis were observed in the two groups in cases of vitreous surgery: anatomical success rate and functional outcomes for HM-MH with foveoschisis were markedly poorer than that for cases of HM-MH without foveoschisis, and multiple procedures might be required. By the contrast, better results seemed to be achieved using the posterior buckle technique for patients with HM-MH and concomitant foveoschisis. Moreover, when compared, final anatomical and functional outcomes seem to be less satisfactory than in emmetropic eyes. Postoperative non-closure or reopening of the macular hole is more common in eyes with HM-MH and concomitant foveoschisis, and possible retinal detachment may occur in these patients.

Conclusions

Despite similar surgical procedures, anatomical and functional results after vitreous surgery in cases of HM-MH may be very different from series to series. The prognosis is generally better in cases involving only HM-MH without foveoschisis than in cases with MH and associated foveoschisis. Persistent MHs are more frequent in eyes with concomitant retinoschisis, and this seems to represent a possible risk factor for late retinal detachment in the case of unsuccessful vitreous surgery. However, although vitrectomy can lead to anatomical and visual improvements, an higher axial length?>?30 mm and the presence of a posterior staphyloma seem to remain the two most important risk factors for poor visual outcomes. For these reasons, a different surgical approach, including macular buckling, might be considered in casse of HM-MH and concomitant myopic foveoschisis, in order to counteract the traction exerted by the posterior staphyloma.     

Reducing wait time for cataract surgery: comparison of 2 historical cohorts of patients in Montreal

Objective: A cataract efficiency program was implemented in Montreal in 2003 to decrease surgery wait time. Our goal was to determine whether health, adverse events during wait time, and outcome of patients presenting for cataract surgery differed from 1999 to 2006 in Montreal.Design: Prospective preoperative and postoperative observational study performed at 2 time points 6 years apart.Participants: Patients awaiting first-eye cataract surgery at Maisonneuve-Rosemont Hospital: 509 patients in 1999-2000 and 206 patients in 2006-2007.Methods: Patients awaiting first-eye cataract surgery were recruited from Maisonneuve-Rosemont Hospital in 1999-2000 (n = 509) and a second cohort was recruited in 2006-2007 (n = 206). Date of entry onto the hospital waiting list and date of cataract surgery were recorded. About 2 weeks before surgery, patients were asked about accidents and falls while waiting, visual difficulty, and satisfaction with vision and wait time. Visual acuity was measured in each eye. Patients also completed interviewer-administered questionnaires: the 5-item Cataract Symptom Scale, Visual Function-14 Questionnaire (VF-14), Short Form Health Survey-36, Geriatric Depression Scale, and the 14-item Systemic Comorbidity Scale. The interview was repeated after surgery.Results: In 1999, 39% of patients waited more than 6 months for cataract surgery, and this was reduced to 29% in 2006. Patients had better preoperative visual acuity in the surgical eye, less visual difficulty, and fewer cataract symptoms, and reported fewer accidents while waiting for surgery in 2006. The change in visual acuity after surgery was nonetheless the same in the 2 cohorts. The 2006 cohort achieved significantly higher VF-14 scores and reported more satisfaction with vision after surgery than did the 1999 cohort.Conclusions: Patients had cataract surgery sooner in the disease process in 2006-2007 compared with 1999-2000, with changes in visual acuity after surgery that were clinically significant in both cohorts.     

Combined horizontal rectus muscle minimally invasive strabismus surgery for exotropia

Objective: To evaluate combined horizontal rectus muscle minimally invasive strabismus surgery (MISS) for exotropia.Design: Case series.Participants: Fifty-two consecutive exotropic patients operated on by 1 surgeon with MISS combined unilateral lateral rectus muscle recession and medial rectus muscle plication.Methods: Alignment, binocular single vision, conjunctival injection and swelling, and complications during the first 6 postoperative months were recorded prospectively. Conjunctival swelling and injection on the first postoperative day were scored retrospectively and compared with historic controls operated on with combined recession-plication or recession-resection using a limbal approach.Results: Conjunctival swelling and injection were mainly mild on the first postoperative day and less pronounced than after surgery with a limbal approach (comparison of swelling and injection for MISS vs limbal opening recession-plication p < 0.001 and for MISS vs limbal opening recession-resection p < 0.001). A conversion to a limbal approach was necessary in 3/104 (3%, 95% CI 1%-7%) of all muscles. No scleral perforation or other serious complication was observed, and no patient needed a repeat operation within 6 months (0/49, 0%, 95% CI 0%-6%).Conclusions: This study demonstrates that small-incision, minimal dissection combined recession-plication surgery induces less conjunctival swelling and injection compared with the usual limbal approach.     

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.     

Risk factors for a postoperative intraocular pressure spike after phacoemulsification

Background: The aim of our study was to examine several potential risk factors for intraocular pressure (IOP) spikes 2 to 3 hours after phacoemulsification.Methods: 50 eyes of 50 consecutive patients undergoing uncomplicated phacoemulsification under topical anesthesia were included in this prospective study. The following variables were recorded:preoperative IOP, nuclear colour,cortical lens opacity,posterior subcapsular lens opacity,patient age;and presence or absence of preexisting glaucoma.Results: The mean IOP at each time interval was as follows: preoperatively, 14.5 (SD 3.4) mm Hg; 2-3 hours postoperatively, 23.1 (7.0) mm Hg; and 24 hours postoperatively, 17.0 (6.0) mm Hg. The postoperative IOP was significantly higher than baseline at 2-3 hours (p < 0.001) and at 24 hours (p = 0.002). Overall there were 10 cases (20%) of IOP spikes 2-3 hours postoperatively. Higher mean baseline IOP was significantly associated with postoperative IOP spikes (p = 0.013). Patient age, sex, operating surgeon, absolute phacoemulsification time, lens nuclear colour, cortical opacity, and posterior opacity were not significantly different between groups with or without an IOP spike (p > 0.05).Interpretation: Patients with high IOP at the preoperative assessment are more likely to have IOP spikes after surgery and should be scheduled at the start of the operating list. In a day-case setting with restricted opening hours, postoperative checks in those patients at risk of IOP spikes can then coincide with the time IOP reaches its peak.     

Axial Length Measurement Using Partial Coherence Interferometry in Myopic Children: Repeatability of the Measurement and Comparison with Refractive Components

Purpose

To evaluate the test–retest repeatability of axial length (AL) measurements made with the IOLMaster in children with a wide range of myopic refractive errors, and to clarify the relationship between the AL and other refractive components.

Methods

The subjects were 95 children (mean age ± SD, 10.8 ± 1.3 years; range, 7–13 years; mean refractive error; ?4.37 ± 1.43 D; range, ?1.50 to ?8.19 D) who participated in a myopia-control trial. The AL of the right eye was measured three times using an IOLMaster, and the mean value was regarded as the representative measurement. After 5?min, the measurement was performed again, and the repeatability was evaluated by analyzing the distribution of differences between the two measurements. The relationships between the AL and age, cycloplegic autorefraction (RE), and corneal radius of curvature (CR) were also examined.

Results

The repeatability of the IOLMaster measurements was ±0.05?mm (corresponding to a refractive error of ±0.12 D) and was not affected by age or RE. AL was negatively correlated with RE (RE = ?0.68 × AL + 12.74, r = ?0.37) and positively correlated with CR (CR = 0.21 × AL + 2.53, r = 0.69). The highest correlation was found between the ratio of AL to CR and RE (AL/CR = ?0.04 × RE + 3.08, r = ?0.76). No association was observed between age and AL, nor between CR and RE.

Conclusions

The IOLMaster provides high repeatability in AL measurement in myopic children. The associations between AL and each refractive component found in this study were consistent with those in previous studies that used the ultrasound A-mode method, except for slightly higher AL/CR ratios in our study.?Jpn J Ophthalmol 2007;51:105–110 © Japanese Ophthalmological Society 2007

     

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.     

Changes in corneal thickness, curvature, and anterior chamber depth during the menstrual cycle

Objective: To determine the variations in corneal thickness values, keratometry readings, and anterior chamber depths (ACD) during the menstrual cycle of young women using the noncontact Scheimpflug imaging technique.Design: Prospective cohort study.Participants: Fourteen women with regular menstrual cycles who were not taking contraceptive pills were enrolled and had measurements taken every other day during a full menstrual cycle, starting from the first day. None used contact lenses or regular medication, and none had systemic disease or history of eye surgery.Methods: The thickness at the centre, superior, inferior, temporal, nasal, and thinnest point of the cornea, the kerato-metry readings, and the ACD values measured with the Pentacam were recorded. We used data on days 1, 3, and 5 of the studied cycle, and counting backwards, 2, 4, 6, 12, 14, and 16 days before the first day of the next cycle.Results: The mean differences between 2 points of time were not statistically significant (p < 0.05) for any variable. The mean difference between any 2 paired thickness measurements was less than 5.0 µm.Conclusions: Contrary to our expectations and previous findings using ultrasound pachymetry, we found no clinically or statistically significant differences between the repeated measurements with the Pentacam. This could indicate that the Pentacam is a clinical tool with less variability when performing serial measurements and follow-up examinations.