Profile of angle closure in a tertiary care center in north India

Purpose:

To study the demographic and clinical profile of the types of primary angle closure patients presenting at a tertiary care center in North India.

Materials and Methods:

Clinic records of patients diagnosed as primary angle closure were reviewed. International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification scheme was used to categorize patients. Demographic and clinical data including prior management was collected and analyzed. Main Outcome measures were age, sex, symptomatology, best corrected visual acuity (BCVA), intraocular pressure (IOP), gonioscopy, optic disc assessment and visual field defects. Logistic regression model and receiver operating curve (ROC) were calculated for predictors of type of glaucoma.

Results:

Eight hundred and fourteen patients (1603 eyes; males: 380, females: 434) were diagnosed to have various subtypes of angle closure. Mean (±SD) age at presentation was significantly higher for males (57.57 ± 11.62 years) as compared to females (53.64 ± 10.67 years) (P < 0001). Primary angle closure glaucoma (PACG) was most frequently diagnosed subtype (49.38%) followed by Primary angle closure (PAC) (39.68%) and Primary angle closure suspect (PACS) (10.93%) respectively. The three subtypes differed significantly among their mean IOP (on ANOVA, F = 14.04; P < 0001 using Greenhouse-Geisser correction). Univariate analysis was done to find significant predictors for the outcome of PACG. Logistic regression model and ROC containing the significant predictors yielded a very high AUC of 0.93 with strong discriminatory ability for PACG.

Conclusion:

In our hospital-based study, the significant predictors for the outcome of PACG included male gender, diminution of vision, the presence of pain and worsening grades of BCVA. Nearly half of PACG presented with advanced disease. In spite of one-third of the patients being diagnosed as angle closure prior to referral, only 8.34% had iridotomy (laser or surgical) done.     

Efficacy of bimatoprost 0.03% in reducing intraocular pressure in patients with 360° synechial angle-closure glaucoma: a preliminary study

Context:

Peripheral anterior synechiae (PAS; synechiae anterior to functional trabecular meshwork) formation in primary angle-closure glaucoma (PACG) hampers access to uveoscleral outflow. Thus, the role of bimatoprost in such patients with 360° synechiae was evaluated.

Aims:

To assess efficacy and safety profile of bimatoprost 0.03% in lowering intraocular pressure (IOP) in 360° synechial angle-closure glaucoma patients.

Settings and Design:

This was a prospective, non-randomized, non-comparative, selective analysis, single-center pilot study.

Materials and Methods:

A total of 23 eyes of 20 Indian chronic angle-closure glaucoma (CACG) patients with IOP greater than 21 mmHg, 360° PAS and no visual potential in the study eye underwent detailed eye examination. Baseline IOP was measured and YAG peripheral iridotomy was performed for complete angle-closure reconfirmation. Bimatoprost 0.03% was administered for 8 weeks as once-daily evening dose. IOP reduction within treatment group was determined with “paired t-test”.

Results:

The mean reduction in IOP from baseline to 8 weeks of bimatoprost therapy was 15.3 ± 9.5 mmHg (P < 0.001). The most commonly observed adverse event was conjunctival hyperemia (35%). Bimatoprost was well tolerated in the study.

Conclusions:

In this study, exclusively involving patients with 360° synechial angle-closure glaucoma and no visual potential, bimatoprost 0.03% treatment demonstrated a statistically significant IOP reduction. Hence, it can be inferred that bimatoprost 0.03% is an efficacious treatment modality in this subgroup of patients for reducing IOP.     

An ultrasound biomicroscopic study of the anterior segment in Indian eyes with primary angle-closure glaucoma

PURPOSE: To evaluate the presence of plateau iris in eyes with primary angle-closure glaucoma (PACG) after laser peripheral iridotomy by gonioscopy and ultrasound biomicroscopy and to evaluate the pathogenesis of this condition by comparing the UBM parameters of these eyes with those in normal subjects. PATIENTS AND METHODS: This prospective study was carried out in the Glaucoma clinic of a tertiary eye care center. A detailed clinical examination including applanation tonometry, indentation gonioscopy with a Sussman four-mirror gonioscope, and ultrasound biomicroscopic examination in one randomly selected eye of 55 patients (55 eyes) with PACG who had undergone laser peripheral iridotomy and 22 normal subjects (22 eyes). RESULTS: Among the PACG eyes, 40% (22/55) had an open angle (angle opening distance > 130 microns) and 60% (33/55) eyes had a narrow angle (angle opening distance 相似文献   

Nd:Yag laser iridotomy in Shaffer-Etienne grade 1 and 2:angle widening in our case studies

AIM:To obtain widening of a potentially occludable angle, in according to Kanski’s indications, through preventive Nd:Yag laser iridotomy. The observational study was performed by using gonioscopy for the selection and follow-up of 1165 treated eyes and exploiting Shaffer-Etienne gonioscopic classification as a quality/quantity test of the angle recession.METHODS:Between September 2000 and July 2012, 586 patients were selected at the Outpatients’ Ophthalmological Clinic of the Policlinico Umberto I of Rome in order to undergo Nd:Yag laser iridotomy. A Goldmann type contact lens, Q-switched mode, 2-3 defocus, and 7-9 mJ intensity with 2-3 impulse discharges were used for surgery.RESULTS:From as early as the first week, a whole 360° angle widening were evident in the patients, thus showing the success of Nd:Yag laser iridotomy in solving relative pupil block. The angle remained narrow by 270° in 14 eyes only, despite repetitions of further treatment with laser iridotomy in a different part of the iris, twice in 10 eyes and three times in 4 eyes.CONCLUSION:Nd:Yag laser iridotomy revealed itself as being a safe and effective treatment in widening those critical Shaffer-Etienne grade 1 and 2 potentially occludable angles.     

Prospective case series on trabecular-iris angle status after an acute episode of phacomorphic angle closure

AIM:To investigate the trabecular-iris angle with ultrasound biomicroscopy (UBM) post cataract extraction after an acute attack of phacomorphic angle closure.METHODS: This prospective study involved 10 cases of phacomorphic angle closure that underwent cataract extraction and intraocular lens insertion after intraocular pressure (IOP) lowering. Apart from visual acuity and IOP, the trabecular-iris angle was measured by gonioscopy and UBM at 3 months post attack.RESULTS: In 10 consecutive cases of acute phacomorphic angle closure from December 2009 to December 2010, gonioscopic findings showed peripheral anterior synechiae (PAS) ≤ 90° in 30% of phacomorphic patients and a mean Shaffer grading of (3.1±1.0). UBM showed a mean angle of (37.1°±4.5°) in the phacomorphic eye with the temporal quadrant being the most opened and (37.1°±8.0°) in the contralateral uninvolved eye. The mean time from consultation to cataract extraction was (1.4±0.7) days and the mean total duration of phacomorphic angle closure was (3.6±2.8) days but there was no correlation to the degree of angle closure on UBM (Spearman correlation P=0.7). The presenting mean IOP was (50.5±7.4) mmHg and the mean IOP at 3 months was (10.5±3.4) mmHg but there were no correlations with the degree of angle closure (Spearman correlations P=0.9).CONCLUSION:An open trabecular-iris angle and normal IOP can be achieved after an acute attack of phacomorphic angle closure if cataract extraction is performed within 1 day - 2 days after IOP control. Gonioscopic findings were in agreement with UBM, which provided a more specific and object angle measurement. The superior angle is relatively more narrowed compared to the other quadrants. All contralateral eyes in this series had open angles.     

Damage patterns of retinal nerve fiber layer in acute and chronic intraocular pressure elevation in primary angle closure glaucoma

AIM: To observe the differences of damage patterns of retinal nerve fiber layer (RNFL) between acute and chronic intraocular pressure (IOP) elevation in primary angle closure glaucoma (PACG) using optical coherence tomography (OCT). METHODS: Twenty-four patients (48 eyes) with unilateral acute PACG (APACG) attack in the 6 months after admission and 36 patients (64 eyes) with chronic PACG (CPACG) were included in this prospective study. For all cases, IOP has been controlled under 21mmHg after treatment. Using stratus OCT, the RNFL thickness was assessed in eyes with PACG within 3 days, 2 weeks, 1, 3 and 6 months after IOP was controlled. Repeated measures ANOVA was used to examine the changes of RNFL thickness at different time after IOP being controlled in both acute attack eyes and unaffected fellow eyes of APACG and eyes with CPACG. RESULTS: The mean RNFL thickness for the APACG- attacked eyes increased significantly within 3 days (121.49±23.84)μm after acute onset and then became thinner along with time [(107.22±24.72)μm at 2 weeks,(93.58±18.37)μm at 1 month, (84.10±19.89)μm at 3 months and (78.98±19.17)μm at 6 months]. In APACG-attacked eyes, there were significant differences of average RNFL thickness at 5 different times after IOP was controlled (P＜0.001). In the APACG unaffected fellow eyes and CPACG eyes, there were no significant differences in mean RNFL thickness at 5 different times(F=0.450, P=0.104 in APACG unaffected fellow eyes and F=1.558, P=0.200 in CPACG eyes). There was significant difference for interaction between time periods and groups (F=1.912, P=0.003). CONCLUSION: RNFL damage patterns are different under different IOP elevated courses. In APACG, RNFL was found to be swollen and thickening right after acute attack and then becomes thinning and atrophy along with the time, while RNFL was found to be diffused thinness in CPACG.     

Bleb needling outcomes for failed trabeculectomy blebs in Asian eyes:a 2-year follow up

AIM:To describe the outcomes of bleb needling in primary glaucoma in an Asian tertiary eye centre over a 2y period. To compare the success rates between primary angle-closure glaucoma (PACG) and primary open angle glaucoma (POAG). Lastly, to identify factors associated with success of bleb needling.METHODS:This was a retrospective review of 227 patients who underwent bleb needling between June 2009 and June 2011 in Singapore National Eye Centre. The 5-fluorouracil (5-FU) augmented bleb needling was performed either at the slit lamp or in the operating theatre. Repeat bleb needlings were performed as necessary. Complete success was defined as maintenance of intraocular pressure (IOP) ≥6 mm Hg and ≤21 mm Hg, in the absence of further surgery or use of antiglaucoma medication. Qualified success met the above criteria with or without use of antiglaucoma medications.RESULTS:One hundred and seventy-five eyes completed the two-year follow up. Sixty-nine percent of participants had POAG and 31% had PACG. The mean interval between filtering surgery and bleb needling was 299.9±616.4d for POAG and 167.1±272.2d for PACG. Mean needling attempts were 1.9±1.4 and 2±1.6 for POAG and PACG respectively. In general, there was a statistically significant reduction of IOP ranging from 21.9% to 26.8% from month 1 through to month 24. The complete success rates at month 6 were 70.0% for POAG and 65.7% for PACG. At month 12, this decreased to 62.2% for POAG and PACG and at month 24, 57.9% for POAG and 63.0% for PACG respectively. The qualified success rates at month 6 for POAG and PACG were 23.8% and 29.9% respectively, 32.2% and 29.2% at month 12, and 34.7% and 29.6% at month 24. The success rates between POAG and PACG were not significantly different (P>0.05 for complete and qualified success at months 6, 12 and 24). An increased number of needlings and higher pre-needling IOP were associated with failure.CONCLUSION:The5-FU augmented bleb needling within one year of trabeculectomy in Asian eyes can provide clinically significant IOP lowering of more than 20% for 2y. POAG and PACG had similar complete success rates (58% and 63% respectively). Factors associated with greater risk of procedure failure included increased number of needlings and higher pre-needling IOP. Asian eyes have a greater propensity for scarring but bleb needling, if performed in a timely manner can rescue bleb function.     

Laser in-situ keratomileusis for refractive error following radial keratotomy

Aim:

To evaluate the safety and efficacy of laser in-situ keratomileusis (LASIK) in eyes with residual/induced refractive error following radial keratotomy (RK).

Design:

Retrospective study.

Materials and Methods:

A retrospective analysis of data of 18 eyes of 10 patients, who had undergone LASIK for refractive error following RK, was performed. All the patients had undergone RK in both eyes at least one year before LASIK. Parameters like uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), contrast sensitivity, glare acuity and corneal parameters were evaluated both preoperatively and postoperatively.

Statistical Software:

STATA-9.0.

Results:

The mean UCVA before LASIK was 0.16±0.16 which improved to 0.64 ± 0.22 (P < 0.001) after one year following LASIK. Fourteen eyes (out of 18) had UCVA of ≥ 20/30 on Snellen''s acuity chart at one year following LASIK. The mean BCVA before LASIK was 0.75 ± 0.18. This improved to 0.87 ± 0.16 at one year following LASIK. The mean spherical refractive error at the time of LASIK and at one year after the procedure was –5.37 ± 4.83 diopters (D) and –0.22 ± 1.45D, respectively. Only three eyes had a residual spherical refractive error of ≥ 1.0D at one year follow-up. In two eyes, we noted opening up of the RK incisions. No eye developed epithelial in-growth till 1 year after LASIK.

Conclusion:

LASIK is effective in treating refractive error following RK. However, it carries the risk of flap-related complications like opening up of the previously placed RK incisions and splitting of the corneal flap.     

The efficacy of Ahmed glaucoma valve drainage devices in cases of adult refractory glaucoma in Indian eyes

Aim:

To evaluate the efficacy of Ahmed glaucoma valve (AGV) drainage devices in cases of adult refractory glaucoma in Indian eyes.

Settings and Design:

Retrospective interventional case series study.

Materials and Methods:

Fifty two eyes of 32 patients of refractory glaucoma in the age group of 35 to 60 years who underwent AGV implantation with or without concomitant procedures from January 2003 to Jan 2007 were studied. Of these, 46 eyes (88%) had undergone filtering surgery earlier whereas remaining eyes underwent primary AGV implantation following failure of maximal medical therapy. The follow up ranged between 12 months to 48 months

Results:

Eighteen eyes (35%) had undergone phacoemulsification with AGV implantation, penetrating keratoplasty (PK) with AGV and intraocular lens (IOL) implantation in 13 eyes (25%), AGV over preexisting IOL in eight eyes (15%). AGV implantation alone was done in six (11%) eyes. Anterior chamber (AC) reconstruction with secondary IOL and AGV was performed in the remaining eyes. The mean intra ocular pressure (IOP) decreased from 36.3 ± 15.7 mm Hg to 19.6 ± 9.2 mm Hg. Complete success as per criteria was achieved in 46 eyes (88%). None of the eyes had failure to maintain IOP control following AGV.

Conclusion:

The AGV resulted in effective and sustained control of IOP in cases of adult refractory glaucoma in intermediate follow up.     

Comparison of surgical outcomes after phacotrabeculectomy in primary angle-closure glaucoma versus primary open-angle glaucoma

Purpose:

To compare postoperative outcomes and assess factors associated with intraocular pressure (IOP) reduction after phacotrabeculectomy in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

Methods:

This is a retrospective study of patients who underwent phacotrabeculectomy between 2010 and 2013. Factors including age, gender, visual field (VF), the number of glaucoma medications used, biometric changes, IOP, and surgical success rates were compared between groups.

Results:

There were 27 PACG and 34 POAG patients. The PACG group had a greater mean IOP reduction after phacotrabeculectomy compared to the POAG group (5.5 ± 7.9 mmHg versus 2.0 ± 4.2 mmHg; p = 0.03). However, the final mean IOP was similar between the two groups (PACG: 12.2 ± 4.8 mmHg, POAG: 12.3 ± 3.1 mmHg; p = 0.92). Phacotrabeculectomy resulted in a mean decrease in axial length (AL) of 0.16 ± 0.15 mm in PACG and 0.16 ± 0.11 mm in POAG (p = 0.96), and an increase in anterior chamber depth (ACD) of 1.41 ± 0.91 mm in PACG, and 0.87 ± 0.86 mm in POAG (p = 0.04). At 2 years follow-up, the cumulative success rate of phacotrabeculectomy was 74% in PACG and 62% in POAG. Multivariate analysis found that early glaucoma stage, greater postoperative increase in ACD, and high preoperative IOP were factors associated with greater IOP reduction.

Conclusion:

Postoperative success rates and mean IOP on the final visit after phacotrabeculectomy were similar between the PACG and POAG groups. Factors associated with IOP reduction were greater postoperative increase in ACD, and high preoperative IOP.     

Retinal sensitivity improvement after intravitreal triamcinolone acetonide injection for macular edema secondary to branch retinal vein occlusion

Purpose:

To evaluate the effect of intravitreal triamcinolone acetonide (IVTA) on retinal sensitivity in cases of macular edema(ME) secondary to branch retinal vein occlusion (BRVO).

Materials and Methods:

Total of 14 eyes of 14 cases of BRVO were included in this prospective study. In each eye, at baseline and 1, 3, and 6 months after IVTA injection, logMAR visual acuity, central 4° retinal sensitivity by MP-1 microperimetry, and optical coherence tomography foveal thickness were assessed.

Results:

Cases ages ranged from 60 to 79 years (mean 68 ± 8 years). At 1, 3, and 6 months, the logMAR visual acuity had increased from 0.71 ± 0.21 to 0.42 ± 0.21, 0.46 ± 0.30, and 0.46 ± 0.27; the mean foveal thickness had decreased from 540 ± 88 μm to 254 ± 51 μm, 288 ± 84 μm, and 280 ± 91 μm; and the mean retinal sensitivity had increased from 4.7 ± 2.5 dB to 7.9 ± 2.7 dB, 8.2 ± 3.6 dB, and 8.3 ± 4.6 dB, respectively.

Conclusion:

In eyes with ME secondary to BRVO, IVTA injections result in a significant increase in not only the visual acuity but also the central 4° retinal sensitivity in 6 months follow-up.     

Changes in anterior chamber configuration after cataract surgery as measured by anterior segment optical coherence tomography

Purpose

To evaluate the changes in anterior chamber depth (ACD) and angle width induced by phacoemulsification and intraocular lens (IOL) implantation in normal eyes using anterior segment optical coherence tomography (AS-OCT).

Methods

Forty-five eyes (45 patients) underwent AS-OCT imaging to evaluate anterior chamber configuration before and 2 days after phacoemulsification and IOL implantation. We analyzed the central ACD and angle width using different methods: anterior chamber angle (ACA), trabecular-iris angle (TIA), angle opening distance (AOD), and trabecular iris surface area (TISA) in the nasal and temporal quadrants. Comparison between preoperative and postoperative measurement was done using paired t-tests and each of the angle parameters was analyzed with Pearson correlation testing. Subgroup analyses according to the IOL and axial length were performed with a general multivariate linear model adjusted for age.

Results

Before surgery, the mean anterior chamber angle widths were 23.21 ± 6.70° in the nasal quadrant and 24.89 ± 7.66° in the temporal quadrant. The mean central ACD was 2.75 ± 0.43 mm. After phacoemulsification and IOL implantation, the anterior chamber angle width increased significantly to 35.16 ± 4.65° in the nasal quadrant (p = 0.001) and 36.03 ± 4.86° in the temporal quadrant (p = 0.001). Also, central ACD increased to 4.14 ± 0.31 mm (p = 0.001). AOD, TISA, and TIA increased significantly after cataract surgery and showed positive correlation with ACA.

Conclusions

After cataract surgery, the ACD and angle width significantly increased in eyes with cataract. AS-OCT is a good method for obtaining quantitative data regarding anterior chamber configuration.     

Anterior segment changes after pharmacologic mydriasis using Pentacam and optical coherence tomography in angle closure suspects

AIM:To compare the dynamic changes of anterior segment parameters especially iris morphology induced by pharmacologic mydriasis between angle closure suspects and normal controls.METHODS:The study group comprised 19 eyes of 19 angle closure suspects and 19 eyes of 19 age- and sex-matched normal open-angle eyes. Pentacam and optical coherence tomography measurements before and 30min after instillation of compound tropicamide eye drop were performed and compared. Biometric evaluations of iris tomography and anterior chamber angle were estimated by a customized image-processing software.RESULTS:Baseline axial length, iris cross sectional area and volume did not differ significantly between angle closure suspects and normal controls. Angle closure suspects had smaller pupil size, narrower anterior segment dimension and axial length, thinner iris with greater curve in comparison with normal controls. Pharmacologic mydriasis led to significant increments in iris thickness at 750 μm, anterior chamber depth and volume, whereas significant decrements in iris curve, cross sectional area and volume in both groups. Angle opening distance at 500 μm was increased significantly in normal controls (from 0.465±0.115 mm to 0.539±0.167 mm, P=0.009), but not in angle closure suspects (from 0.125±0.100 mm to 0.145±0.131 mm, P=0.326). Iris volume change per millimeter of pupil dilation (△IV/△PD) decreased significantly less in angle closure suspects than normal controls (-2.47±1.33 mm² vs -3.63±1.58 mm², P=0.019). Linear regression analysis showed that the change of angle opening distance at 500 μm was associated most with the change of central anterior chamber depth (β=0.841, P=0.002) and △IV/△PD (β=0.028, P=0.002), followed by gender (β=0.062, P=0.032).CONCLUSION:Smaller iris volume decrement per millimeter of pupil dilation is related significantly with the less anterior angle opening in angle closure suspects after pharmacologic mydriasis. Dynamic iris change may be as a prospective indicator of iris compressibility and angle closure glaucoma.     

Structural sequelae and refractive outcome 1 year after laser treatment for type 1 prethreshold retinopathy of prematurity in Asian Indian eyes

Aim:

The aim was to study the structural sequelae and refractive outcome after laser treatment for Type 1 prethreshold retinopathy of prematurity (ROP) in Asian Indian eyes.

Materials and Methods:

A retrospective chart review of infants with Type 1 prethreshold ROP (defined according to the Early Treatment for Retinopathy of Prematurity study) undergoing laser treatment at a tertiary center between January 2004 and December 2008 was done. The 1-year outcome of infants was analyzed.

Results:

Sixty-nine eyes of 36 infants were included. The mean birth weight was 1121.69 ± 254.81 g and the gestational age was 28.99 ± 2.03 weeks. Sixty-five eyes (94.2%) had zone 2 and 4 (5.8%) had zone 1 disease. Forty-four (63.77%) eyes had stage 2 ROP with plus disease and 25 (36.23%) eyes had prethreshold (fewer than five contiguous or eight cumulative clock hours) stage 3 ROP with plus disease. None of the eyes developed retinal structural sequelae. On cycloplegic retinoscopy, 59.4% eyes had nonsignificant hyperopia [spherical equivalent (SE) ≤ 4 D], 14.5% eyes had no refractive error (SE 0 D), 24.7% eyes had low myopia (SE < 5 D), and 1.4% eyes had high myopia (SE > 5.0 D). Eyes developing myopia were associated with a greater number of clock hours of ROP, greater number of laser spots used, and a longer time to disease regression. Two infants (5.6%) had esotropia and one (2.8%) had exotropia.

Conclusion:

Asian Indian infants treated for Type 1 prethreshold ROP did not develop retinal structural sequelae. Myopia was seen in nearly one-fourth of the eyes.The risk factors for myopia were a greater number of clock hours of ROP, greater number of laser spots, and a longer time to regression of ROP.     

A comparative study between intravitreal triamcinolone and bevacizumab for macular edema due to central retinal vein occlusion with poor vision

Aim:

To compare the effect of intravitreal bevacizumab and triamcinolone in patients with macular edema after central retinal vein occlusion (CRVO), presenting with poor visual acuity.

Materials and Methods:

It was a retrospective, comparative case series of 38 consecutive eyes, with macular edema secondary to CRVO, with 20/200 or worse vision, which were treated primarily either with intravitreal bevacizumab (1.25 mg; 24 eyes) or intravitreal triamcinolone (4 mg; 14 eyes). During follow-up, 3.6 ± 0.8 re-injections of bevacizumab and 2.4 ± 0.5 re-injections of triamcinolone were administered (P = 0.080). The main outcome measures were the best-corrected visual acuity and the central macular thickness by optical coherence tomography during 12 months of follow-up.

Results:

At 12 months, visual acuity (logMAR) was changed from 1.03 ± 0.39 (baseline) to 0.92 ± 0.39 (P = 0.374) and the central macular thickness was reduced from a baseline of 713.6 ± 179.3 µm to 310.8 ± 205.2 µm (P = 0.000). Neither the bevacizumab nor triamcinolone groups varied significantly in visual acuity and central macular thickness at 1, 3, 6, and 12 months after treatment. Neovascular glaucoma developed in two of the 14 eyes (14%) in the triamcinolone group.

Conclusion:

In patients with CRVO and poor vision, intravitreal bevacizumab and intravitreal triamcinolone were associated with a reduction in macular edema; however, neither treatment achieved significant visual acuity improvement by the 12-month follow-up.     

Comparison of ultrasound biomicroscopy and spectral-domain anterior segment optical coherence tomography in evaluation of anterior segment after laser peripheral iridotomy

AIM: To quantitatively assess narrow anterior chamber angle using spectral-domain anterior segment optical coherence tomography (SD-AS-OCT) and ultrasound biomicroscopy (UBM), and to evaluate the correlations and consistency between SD-AS-OCT and UBM. METHODS: Fifty-five eyes from 40 patients were examined. Patients were diagnosed with primary angle-closure glaucoma (PACG) remission (11 eyes from 8 patients), primary angle closure (PAC, 20 eyes from 20 patients) and PAC suspect (24 eyes from 12 patients). Each eye was examined by SD-AS-OCT and UBM after laser peripheral iridotomy (LPI). The measurements of SD-AS-OCT were angle open distance (AOD), anterior chamber angle (ACA), trabecular iris angle (TIA), and trabecular iris space area (TISA). UBM measurements were AOD and TIA. Correlations of AOD500 and TIA500 between UBM and AS-OCT were assessed. All parameters were analysed by SPSS 16.0 and MedCalc. RESULTS: ACA, TIA and AOD measured by SD-AS-OCT reached a maximum at the temporal quadrant and minimum at the nasal quadrant. TISA reached the maximum at the inferior and minimum at the superior quadrant. Group parameters of AOD500 and AOD750 showed a linear positive correlation, and AOD750 had less variability. UBM outcomes of AOD500 and TIA500 were significantly smaller than those of SD-AS-OCT. The results of the two techniques were correlated at the superior, nasal and inferior quadrants. CONCLUSION: Both UBM and SD-AS-OCT are efficient tools for follow-up during the course of PACG. We recommended using parameters at 750 µm anterior to the sclera spur for the screening and follow-up of PACG and PAC. The two methods might be alternatives to each other.     

Detection of progressive macular thickness loss using optical coherence tomography in glaucoma suspect and glaucomatous eyes

Aims

To examine the rate of macular thickness loss using time-domain optical coherence tomography (OCT) in functionally progressing versus non-progressing eyes, determined by standard automated perimetry (SAP).

Methods

Glaucoma suspects (GS) and glaucomatous (G) eyes underwent SAP and OCT imaging every 6 months. Functional progression was determined using pointwise linear regression, defined as 2 contiguous locations losing ≥1.0 dB/year at P<1.0% in the same hemifield. The annual rate of macular thickness loss was calculated from inner and outer regions of the macular map.

Results

72 eyes (43 GS and 29G) with ≥30 months of follow-up were enroled. Fourteen eyes demonstrated SAP progression. The annual rate of macular thickness loss (μm/year) in progressing eyes was faster (all P<0.05) than non-progressing eyes in temporal outer (−1.90±2.97 vs 0.33±2.77), nasal inner (−1.70±2.66 vs 0.14±2.76), superior inner (−2.15±4.57 vs 0.51±2.99), temporal inner quadrants (−2.58±5.05 vs −0.38±2.34), and the average of inner macular quadrants (−1.84±2.90 vs 0.03±2.10). The rate of loss in the nasal inner (P=0.02) and temporal outer (P=0.02) macular regions was associated with optic disc haemorrhage.

Conclusions

Eyes with SAP progression have significantly greater rates of macular thickness loss consistent with glaucomatous retinal ganglion cell atrophy, as compared with non-progressing eyes.     

Analysis of photoastigmatic keratectomy with the cross-cylinder ablation

Aim:

The aim was to evaluate the safety and efficacy of the “cross-cylinder” technique in the correction of astigmatism.

Setting and Design:

A prospective interventional study from a university eye department was conducted.

Material and Methods:

The photoastigmatic refractive keratectomy (PARK) using the “cross-cylinder” technique was performed in 102 eyes of 84 patients with at least 0.75 D of astigmatism. The study population was divided into two groups: in the first group the preoperative astigmatic power ranged from –0.75 D to –3.00 D (group 1), in the second group it ranged from –3.25 D to –6.00 D (group 2). Group 1 included 82 eyes of 67 patients (29 males and 38 females) with a mean cylinder power of –1.90 ± 0.63 D, group 2 included 20 eyes of 17 patients (13 males and 4 females) with a mean cylinder power of -4.28 ± 0.76 D. All eyes were targeted for emmetropia. The results were evaluated using Calossi''s vector analysis method. Six-month postoperative outcomes are presented.

Results:

Six months after PARK the mean sphere for the entire cohort was +0.28 ± 0.75 D (range +2.5 to –2 D), the mean cylindrical power was +0.33 ± 0.51 D (range +2.5 to –1.25 D) and the mean spherical equivalent refraction was +0.73 ± 0.81 D (range +1.75 to –2 D).

Conclusions:

The cross-cylinder technique may be safely used with predictable results for the correction of astigmatism.     

Changes in central retinal artery blood flow after ocular warming and cooling in healthy subjects

Context:

Retinal perfusion variability impacts ocular disease and physiology.

Aim:

To evaluate the response of central retinal artery (CRA) blood flow to temperature alterations in 20 healthy volunteers.

Setting and Design:

Non-interventional experimental human study.

Materials and Methods:

Baseline data recorded: Ocular surface temperature (OST) in °C (thermo-anemometer), CRA peak systolic velocity (PSV) and end diastolic velocity (EDV) in cm/s using Color Doppler. Ocular laterality and temperature alteration (warming by electric lamp/cooling by ice-gel pack) were randomly assigned. Primary outcomes recorded were: OST and intraocular pressure (IOP) immediately after warming or cooling and ten minutes later; CRA-PSV and EDV at three, six and nine minutes warming or cooling.

Statistical Analysis:

Repeated measures ANOVA.

Results:

(n = 20; μ ± SD): Pre-warming values were; OST: 34.5 ± 1.02°C, CRA-PSV: 9.3 ± 2.33 cm/s, CRA-EDV: 4.6 ± 1.27 cm/s. OST significantly increased by 1.96°C (95% CI: 1.54 to 2.37) after warming, but returned to baseline ten minutes later. Only at three minutes, the PSV significantly rose by 1.21 cm/s (95% CI: 0.51to1.91). Pre-cooling values were: OST: 34.5 ± 0.96°C, CRA-PSV: 9.7 ± 2.45 cm/s, CRA-EDV: 4.7 ± 1.12 cm/s. OST significantly decreased by 2.81°C (95% CI: −2.30 to −3.37) after cooling, and returned to baseline at ten minutes. There was a significant drop in CRA-PSV by 1.10cm/s (95% CI: −2.05 to −0.15) and CRA-EDV by 0.81 (95% CI: −1.47 to −0.14) at three minutes. At six minutes both PSV (95% CI: −1.38 to −0.03) and EDV (95% CI: −1.26 to −0.02) were significantly lower. All values at ten minutes were comparable to baseline. The IOP showed insignificant alteration on warming (95% CI of difference: −0.17 to 1.57mmHg), but was significantly lower after cooling (95% CI: −2.95 to −4.30mmHg). After ten minutes, IOP had returned to baseline.

Conclusion:

This study confirms that CRA flow significantly increases on warming and decreases on cooling, the latter despite a significant lowering of IOP.     

Intraocular lens exchange through a 3.2-mm corneal incision for opacified intraocular lenses

Aim:

The aim was to evaluate visual and refractive results and complications of intraocular lens (IOL) exchange through a 3.2 mm corneal incision for opacified IOLs.

Materials and Methods:

This retrospective study comprised 33 eyes of 32 patients with IOL opacification requiring an IOL exchange between July 2003 and March 2007. Exchange surgery was performed through a 3.2-mm temporal clear corneal incision followed by implantation of a new foldable hydrophobic IOL. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), topographical astigmatism, and refractive cylinder were evaluated. Surgically induced astigmatism (SIA) was calculated and complications were recorded.

Results:

Opacification was observed in 25 eyes (76%) with Aqua-Sense, 3 eyes (9%) with Hydroview, 3 eyes (9%) with MemoryLens IOLs, and 2 eyes (6%) with DgR. The mean follow-up period was 36.54 months. An uneventful IOL exchange was achieved in 18 eyes (55%). Zonular dehiscence occurred in 9 eyes (27%), and posterior capsule tear developed in 4 eyes (12%). The mean preoperative BSCVA (mean ± standard deviation, decimal scale) was 0.13 ± 0.08 (mean: 20/150, range 20/2000 to 20/60) and improved to 0.63 ± 0.18 (mean: 20/32, range 20/60 to 20/20, P < 0.001). The mean SIA was 0.70 D. Seven eyes (21%) had 0.5 D or lower SIA.

Conclusion:

IOL exchange is a technically challenging procedure with potential risks of reversing the advantages of a prior small-incision cataract surgery. The use of a small corneal incision for IOL exchange could preserve the advantages of modern phacoemulsification surgery with acceptable SIA related to the procedure.