Clinical reviews

Sulfur hexafluoride (SF6) gas is widely used for internal tamponade during retinal reattachment surgery and is commonly injected into the eye from a 10-mL plastic syringe. The rate of diffusion of SF6 out of a plastic syringe has not bee studied. We measured the percentage of SF6 gas in a 10-mL plastic syringe by gas chromatography, confirmed by infrared spectrometry. Measurements were obtained immediately after aspiration, and at 30 s and 10, 15, 60, 90, and 120 minutes, and 18 hours. A marked decrease in SF6 concentration, from 97% at 30 s to 76% at 60 minutes and 2% at 18 hours, was noted. The results were highly reproducible. Sulfur hexafluoride gas should be injected into the patient's eye as soon as possible after aspiration from the tank to ensure accurate concentrations.

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Background: Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. At a later stage, neovascular or exudative AMD can lead to severe central vision loss that is related to aging-associated cumulative oxidative stress of the human retinal pigment epithelium (hRPE) and choroid capillary. Early prevention with antioxidants is mandatory. The aim of this study was to determine whether and how mannitol can act as an antioxidant.

Methods: The methods used included measurements of cell viability, oxygen free radical (OFR) levels, lipid peroxide (LP) levels, and OFR-related enzyme protein levels.

Results: H(2)O(2) dose-dependently reduced the cell viability of hRPE cells. This negative effect was significantly counteracted by pretreatment with mannitol (1 mM). H(2)O(2) significantly stimulated the formation of OFR and LP. These increases were dose-dependently and significantly blunted by mannitol. Furthermore, treatment with H(2)O(2) was associated with a reduction in the level of catalase, but not of manganese superoxide dismutase (MnSOD). In contrast, it was shown that mannitol protected hRPE cells against the H(2)O(2)-induced oxidative stress by increasing the level of catalase, but not the level of MnSOD.

Conclusion: This study supports an antioxidative role for mannitol that acts through up-regulating the level of catalase, which is decreased by H(2)O(2).

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Aim: To evaluate the refractive and visual outcomes following cataract surgery and implantation of a trifocal toric intraocular lens (IOL) in eyes with low degrees of corneal astigmatism.

Methods: Twenty-six eyes of 22 patients who underwent implantation a trifocal toric IOL (FineVision PODFT, PhysIOL s.a., Liege, Belgium) were enrolled. Phacoemulsification with femtosecond laser, capsular tension ring insertion and intraoperative aberrometry were performed in all cases. All IOLs used showed a cylinder power of 1.00 D. Main outcome measures were refractive error and corrected-distance visual acuity (CDVA) and uncorrected-distance visual acuity (UDVA) values. Eyes were evaluated at 4mo post-surgery.

Results: Totally 50% of eyes showed a spherical equivalent (SE) within ±0.13 D and all of them within ±0.50 D. The mean SE and refractive cylinder were -0.02±0.23 and -0.16±0.22 D, respectively. Vector analysis revealed that 100% of eyes were within ±0.50 D for the SE and cylindrical components (J0 and J45). Refractive changes were not correlated with keratometric changes (P>0.05) showing that the reduction in astigmatism comes from the trifocal toric IOL. Of 81% and 96% of eyes showed UDVA and CDVA of 20/20, respectively. The postoperative mean values of monocular distance Snellen decimal UDVA and CDVA were 0.97±0.05 and 0.99±0.02 (about 20/20), respectively.

Conclusion: Our study suggests that the use of this trifocal toric IOL in patients with low amount of astigmatism provides accurate refractive outcomes and enables them to achieve excellent visual acuity.

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Aim: Colourless solutions of mitomycin C (MMC) and 5-fluorouracil (5-FU) are widely used during trabeculectomy to inhibit postoperative scarring. The poor visibility of these agents on the eye has several drawbacks including the inability to accurately assess the area of treatment. This study examined the utility of using trypan blue dye to colour antimetabolites used during trabeculectomy and the effect of trypan blue on antimetabolite cytotoxicity in vitro.

Methods: For in vitro experiments, MMC (0.4 mg/ml) and 5-FU (25 mg/ml) were reconstituted with or without trypan blue. A lactate dehydrogenase release assay was used to measure drug induced cell death and viable cell number 7 days after treatment. For clinical assessment, trypan blue 0.1% was added to MMC and 5-FU to final concentrations of between 0.01% and 0.05%. The mixture was applied to Tenon’s capsule and sclera via pre-wet or into dry 5×8 mm sponges (MMC and 5-FU) for 3 minutes or by direct subconjunctival injection after completion of surgery (5-FU). Twenty two consecutive patients undergoing trabeculectomy either with or without trypan blue were followed for 2 years postoperatively.

Results: The addition of 0.05% trypan blue to MMC or 5-FU did not alter MMC induced cell death or the number of viable fibroblast in vitro. In vivo, trypan blue clearly delineated the antimetabolite treatment area and facilitated control of excess antimetabolite at the wound margins as well as sponge removal. With direct subconjunctival injection, total staining area varied for a given volume with location of the needle tip. Any leakage from the injection site could be easily seen. No adverse effects attributable to trypan blue were found in 2 years of follow up.

Conclusions: Trypan blue permits delineation of antimetabolite/tissue interactions without affecting cytoxicity for the assays investigated. Trypan blue can be used to visualise antimetabolite soaked sponges, estimate treatment area, and show areas of unintended tissue contact during trabeculectomy. The addition of trypan blue to antimetabolites has potential benefits in clinical, research, and teaching aspects of ocular surgery and therapy.

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Objective: To determine whether trypan blue staining facilitates epiretinal membrane (ERM) removal in proliferative vitreoretinopathy.

Methods: In 10 patients undergoing vitrectomy for proliferative vitreoretinopathy, ERM peeling was performed without staining the tissue, until no additional ERMs were clearly visible. Then, after a fluid-air exchange, 0.06% trypan blue solution was applied onto the retinal surface. After 1 minute, all excess dye was removed and, after an air-fluid exchange, ERM peeling was completed. Excised ERM specimens were analyzed by transmission electron microscopy.

Main outcome measures: For each patient, the efficacy of trypan blue staining of ERMs during surgery was scored.

Results: In all patients, intraoperative staining of ERMs with trypan blue was found to be a useful adjunct, since the dye consistently improved direct visualization and delineation of ERMs and facilitated ERM removal. A clear contrast was created between the stained ERMs and the nonstaining, underlying retina. Electron microscopy showed that only ERM tissue was removed. No adverse reactions related to the use of the dye were observed up to 3 months after surgery.

Conclusions: Trypan blue may be an important new tool in the surgical management of proliferative vitreoretinopathy, since it may allow a more complete and safer ERM removal.

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We describe the usefulness of intracameral injection of trypan blue to highlight vitreous in the anterior chamber. The technique was used in 3 eyes of 3 patients who had vitreous prolapse in the anterior chamber. Trypan blue 0.06% was injected in the anterior chamber under air to visualize and resect the prolapsed vitreous. Trypan blue stained the clear vitreous and improved visualization for a safe and atraumatic vitrectomy. No complications associated with the dye were found.

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Purpose: To evaluate the outcome of surgeries for macular holes using trypan blue to facilitate delamination of the internal limiting membrane.

Design: A retrospective series of 18 patients.

Method: All patients underwent a three-port pars plana vitrectomy with internal limiting membrane delamination using trypan blue 0.06% to assist visualization. The main outcome measures were postoperative visual acuity and clinically evident retinal pigment epithelial changes.

Results: The median preoperative visual acuity was 20/200, and the median postoperative visual acuity was 20/70. All but one macular hole were closed after surgery (94%). At the last recorded follow-up, 10 patients (56%) had improved visual acuity of at least two chart lines. No adverse reaction related to trypan blue was observed up to 1 year postsurgery.

Conclusions: Trypan blue staining of internal limiting membrane may accomplish more complete dissections of the internal limiting membrane and better surgical and visual outcomes.

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Purpose: The purpose of this study was to correlate the ultrastructural morphology of epiretinal and retinal tissue with optical coherence tomography assessment and to investigate the effects of trypan blue staining on internal limiting membrane (ILM) tissue.

Methods: This was a prospective case-comparative study. Consecutive patients were recruited and underwent ILM peel with 0.5 mL of 0.15% trypan blue, and these were compared with a nonrandomized control group (unstained ILM). Patients underwent optical coherence tomography scanning preoperatively and postoperatively at 1.5 and 3 months. Data were collected prospectively to include Snellen visual acuity, macular hole, and operative characteristics. Internal limiting membrane was examined by transmission electron microscopy.

Results: Sixty-four patients underwent macular hole surgery, and complete data were available on 49 patients (17 control subjects and 32 patients who had peeling of stained ILM). Trypan blue staining significantly improved ease and completeness of ILM removal. There was no significant difference in vision, optical coherence tomography characteristics, or macular hole closure rate at 3 months between stained and unstained groups. There was no ultrastructural evidence of alteration of the plane of ILM separation in cases in which trypan blue was used.

Conclusion: Trypan blue stain from these data seems to improve the ease and completeness of the ILM peeling (assessed clinically) and does not show any signs of toxicity.

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Purpose: To validate the Spanish Catquest-9SF and study patient-reported visual function after implantation of a trifocal versus a monofocal intraocular lens (IOL).

Setting: Clinica Baviera, Valencia and Madrid, Spain.

Design: Prospective case series.

Methods: The Catquest-9SF was translated from English to Spanish according to a standard procedure. The Spanish version was validated through Rasch analysis. Patients completed the Catquest-9SF before cataract surgery and 3 months after the surgery. The change in patient-reported visual function caused by surgery, the level of achieved visual function, and satisfaction with vision after surgery were assessed for bilaterally implanted trifocal IOLs versus monofocal IOLs.

Results: The Spanish Catquest-9SF showed very good psychometric properties. Patient-reported achieved visual function was significantly better for those with a trifocal IOL than for those with a monofocal IOL (P < .001). This was also true when the groups were matched for age and ocular comorbidity (P = .006). In multivariate analyses of all cases and matched cases (the same age and no comorbidity), the reported visual function was significantly better with trifocal IOLs than with monofocal IOLs (P = .001 and P = .008, respectively). There was greater improvement after trifocal IOL implantation in the matched cases, although not significant (P = .103).

Conclusions: Results show the Spanish version of Catquest-9SF is a valid patient questionnaire with good psychometric properties. Patients with a trifocal IOL implanted bilaterally reported better visual function than those with a monofocal IOL implanted bilaterally. The change in visual function after surgery was also greater in patients with a trifocal IOL.

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Purpose: To establish the changes produced after implantation of a trifocal intraocular lens (IOL) on retinal nerve fiber layer measurements performed with Fourier-domain optical coherence tomography (OCT).

Methods: This prospective study included 100 eyes of 50 patients with bilateral cataract in surgical range, no other associated ocular involvement, refractive errors between +5 and -5 spherical diopters, and less than 1.5 D of corneal astigmatism. The eyes were operated by phacoemulsification with implantation of 2 different trifocal IOLs (FineVision and AT LISA tri 839MP) in randomized equal groups. Cirrus OCT and Spectralis OCT were performed before surgery and 3 months later. Both analyzed the thickness of the nerve fiber layer and thickness divided by quadrants (6 in case of Spectralis and 4 in case of Cirrus HD).

Results: The mean age of patients was 67.5 ± 5.8 years. The global nerve fiber layer thickness measured with Spectralis OCT was 96.77 μm before surgery and 99.55 μm after. With Cirrus OCT, the global thickness was 85.29 μm before surgery and 89.77 μm after. Statistically significant differences in global thickness measurements between preimplantation and postimplantation of the IOL were found with both OCT in the 2 groups. Statistically significant differences were also found in temporal and superior quadrants.

Conclusions: The implantation of a diffractive trifocal IOL alters the results of the optic nerve fiber layer on Fourier-domain OCT in these patients, which should be taken into account in the posterior study of these patients.

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Purpose: To show the visual and refractive outcomes in cataract patients with corneal astigmatism when bilaterally implanted with a biconvex aspheric toric monofocal intraocular lens (IOL) with a double C-loop haptic-design.
Methods: Forty-seven cataract patients (94 eyes) with corneal astigmatism (≥ 0.75D) were implanted with the monofocal PODEYE toric IOL and assessed for 4– 6 months post-surgery. Measurements included monocular and binocular uncorrected-distance visual acuity (UDVA) and corrected-distance visual acuity (CDVA), under both photopic and mesopic lighting conditions. Refraction, photopic and mesopic contrast sensitivity (with and without glare), and rotational stability were also recorded at the last postoperative visit.
Results: At 4– 6 months, 78.2% and 98.9% of eyes were within ± 0.50D and ± 1.00D of the target refraction, respectively. The mean spherical equivalent and refractive cylinder values were 0.09± 0.35D and − 0.36± 0.35D, respectively. 76.5% and 98.8% of eyes presented a postoperative refractive cylinder of ≤ 0.50D and ≤ 1.00D, respectively. 91.5% and 100% of patients had a binocular UDVA and CDVA of ≥ 20/25, respectively. The mean binocular UDVA and CDVA were 0.02± 0.08 and − 0.02± 0.07 logMAR, respectively. Under mesopic conditions, 78.7% and 83.0% of patients presented a binocular UDVA and CDVA ≥ 20/32, respectively. The mean binocular UDVA and CDVA were 0.15± 0.11 and 0.12± 0.11 logMAR, respectively. The patients showed good contrast sensitivity under photopic and mesopic conditions. The mean absolute IOL rotation was 1.22± 2.21 degrees with 97.87% of eyes having a rotation of < 10 degrees.
Conclusion: This study shows good visual and refractive outcomes for the PODEYE toric IOL when implanted bilaterally in cataract patients with corneal astigmatism.

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Background: The purpose of this study was to record the visual outcomes of patients treated by six surgeons after implantation of a trifocal lens.

Methods: The setting for this study comprised six ophthalmology units and eye clinics in Belgium and France, with a coordinating center in France, and data management and statistical analysis in France and Belgium. Ninety-four eyes from 47 patients were implanted with a trifocal FineVision^® intraocular lens by six surgeons. Monocular and binocular, uncorrected and best distance-corrected, and photopic and mesopic visual acuity was measured, as well as the defocus curve between +4 D and −4 D with best distance correction.

Results: Near and far monocular visual acuities were similar to the data published after bifocal intraocular lens implantation. Intermediate vision was improved, and was demonstrated by scores of near visual acuity as well as far visual acuity with defocus −1.5 D-add lens. Far vision is maintained in mesopic conditions.

Conclusion: The trifocal intraocular lens provides good far, intermediate, and near visual acuity.

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Purpose: To assess the refractive and visual outcomes after implantation of an isofocal optic-design intraocular lens (IOL) with double C-loop haptics following cataract surgery in Japanese eyes.
Methods: This was a single-centre prospective study considering 38 eyes of 19 patients who were implanted with the Isopure Serenity (Beaver-Visitec International, Inc. [BVI], Waltham, USA) IOL. This study analysed the refractive (sphere, cylinder and axis) and visual outcomes at 3 months post-surgery. Specifically, the visual performance was analysed by measuring monocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA) and distance-corrected intermediate visual acuity (DCIVA) at 80 and 66 cm, uncorrected near visual acuity (UNVA), and distance-corrected near visual acuity (DCNVA) at 40 cm. The photopic binocular defocus curve was also measured.
Results: About 100% of the eyes were within ± 1.00D and 89.47% of the eyes within ± 0.50D; the mean postoperative spherical equivalent was 0.12 ± 0.35D. The mean refractive cylinder was – 0.11 ± 0.33D. 89.47% and 97.37% of patients presented a cumulative monocular UDVA and CDVA value of ≥ 20/20, respectively. About 57.89% and 42.11% of patients presented a monocular DCIVA value of ≥ 20/32 at 80 and 66 cm, respectively. About 55.26% of patients presented a monocular DCNVA value of ≥ 20/40. The mean monocular CDVA, DCIVA at 80 cm, DCIVA at 66 cm, and DCNVA were – 0.08 ± 0.05, 0.23 ± 0.13, 0.28 ± 0.13 and 0.35 ± 0.14 logMAR, respectively. The through-focus curve showed good visual acuity at far and intermediate distances with a depth-of-focus value of about 1.75D.
Conclusion: Our current clinical study shows that the implantation of the new isofocal optic-design IOL with double C-loop haptics results in accurate refractive outcomes with excellent visual performance for distance vision and functional intermediate vision in Japanese eyes. The outcomes obtained evidence that this new IOL model is an effective option extending the range of vision when correcting aphakia.

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Purpose: To evaluate the visual outcomes and efficacy of astigmatism correction using a new hydrophobic trifocal toric intraocular lens (IOL).
Methods: This study involved 62 eyes implanted with the FineVision HP Toric IOL. The visual and refractive outcomes were assessed preoperatively and 6 weeks after the surgery. Specifically, monocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA) at 80 and 60 cm and uncorrected near visual acuity at (UNVA) at 40 cm were evaluated. The rotational stability of the lens was also assessed.
Results: Sixty-one eyes (98.39%) were within ± 1.00D and 55 eyes (88.71%) were within ± 0.50 D of spherical equivalent, with a mean value of 0.09± 0.39 D. 51 (82.26%) and 61 (98.39%) eyes had a UDVA of ≥ 20/20 and ≥ 20/25, respectively, and for CDVA these values were as follows: 59 (95.16%) and 62 eyes (100%), respectively. The mean UDVA and CDVA were 0.01± 0.06 and − 0.01± 0.04logMAR, respectively. Greater than or equal to unaided 20/20 vision was achieved at 40 cm in 42 (67.74%), UIVA at 60 cm in 42 (67.74%) and 50 eyes (80.65%) at 80 cm. Those achieving ≥ 20/25 were 56 (90.32%, 40 cm), 59 (95.16%, 60 cm), and 62 eyes (100%, 80 cm). Postoperative mean values were 0.04± 0.07, 0.03± 0.07, and 0.00± 0.07logMAR for UCNVA, UIVA at 60 cm, and UIVA at 80 cm, respectively. The mean rotation of the IOL was 5.8 degrees.
Conclusion: This hydrophobic trifocal toric IOL provides good refractive outcomes with excellent visual acuity across multiple distances, providing a full range of focus.

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Objective: To evaluate visual and subjective outcomes after diffractive intraocular lens (IOL) implantation in clear lens exchange.

Methods: Prospective, non-interventional study of patients undergoing clear lens refractive surgery with implantation of a trifocal IOL. Subjective refraction and visual acuity were analyzed for uncorrected distant visual acuity (UDVA) and corrected distant visual acuity (CDVA) and for uncorrected near visual acuity (UNVA) and corrected near visual acuity (CNVA), 1, 3 and 6 months after surgery. Aberrometry was performed to determine the higher-order root mean-square (RMS). Bilateral contrast sensitivity function was obtained under mesopic conditions. The quality of visual function was evaluated using the VF-14 method.

Results: Mean monocular CDVA was 0.06 ± 0.07 logMAR and mean monocular UNVA was 0.02 ± 0.05 logMAR. Spherical equivalent (SE) 6 months after surgery was 0.03 ± 0.35 D. The safety index for distant vision was 1.0 and the efficacy index was 0.91. Mean higher-order RMS was 0.27 μm. Contrast sensitivity was lower in the postsurgery period, with values within normal ranges for adults. VF-14 value was 92.96.

Conclusion: Diffractive trifocal IOL implantation after clear lens exchange is a safe and effective method that provides excellent outcomes and high quality visual function in distant and near vision.

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Background: In recent years new models of intraocular lenses are appearing on the market to reduce requirements for additional optical correction. The purpose of this study is to assess visual outcomes following bilateral cataract surgery and the implant of a FineVision® trifocal intraocular lens (IOL).

Methods: Prospective, nonrandomized, observational study. Vision was assessed in 44 eyes of 22 patients (mean age 68.4 ± 5.5 years) before and 3 months after surgery. Aberrations were determined using the Topcon KR-1 W wave-front analyzer. LogMAR visual acuity was measured at distance (corrected distance visual acuity, CDVA 4 m), intermediate (distance corrected intermediate visual acuity, DCIVA 60 cm) and near (distance corrected near visual acuity, DCNVA 40 cm). The Pelli-Robson letter chart and the CSV-1000 test were used to estimate contrast sensitivity (CS). Defocus curve testing was performed in photopic and mesopic conditions. Adverse photic phenomena were assessed using the Halo v1.0 program.

Results: Mean aberration values for a mesopic pupil diameter were: total HOA RMS: 0.41 ± 0.30 μm, coma: 0.32 ± 0.22 μm and spherical aberration: 0.21 ± 0.20 μm. Binocular logMAR measurements were: CDVA −0.05 ± 0.05, DCIVA 0.15 ± 0.10, and DCNVA 0.06 ± 0.10. Mean Pelli-Robson CS was 1.40 ± 0.14 log units. Mean CSV100 CS for the 4 frequencies examined (A: 3 cycles/degree (cpd), B: 6 cpd, C: 12 cpd, D: 18 cpd) were 1.64 ± 0.14, 1.77 ± 0.18, 1.44 ± 0.24 and 0.98 ± 0.24 log units, respectively. Significant differences were observed in defocus curves for photopic and mesopic conditions (p < 0.0001). A mean disturbance index of 0.28 ± 0.22 was obtained.

Conclusions: Bilateral FineVision IOL implant achieved a full range of adequate vision, satisfactory contrast sensitivity, and a lack of significant adverse photic phenomena.

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