Optical Analysis of Visual Improvement after Correction of Anisometropic Amblyopia with a Phakic Intraocular Lens in Adult Patients

Anterior Chamber Iris-Fixated Phakic Intraocular Lens Implantation for Treatment of High Anisometropia in Children: Long-term Results

PURPOSE

To evaluate the long-term efficacy of anterior chamber iris-fixated phakic intraocular lens (PIOL) implantation in the treatment of high myopic (> -9.00 diopters [D]) or hyperopic (> +6.00 D) anisometropia in children with intolerance to spectacles or contact lenses.

METHODS

A total of 58 children with anisometropic myopia (range: -9.25 to -18.50 diopters [D]) and 13 children with anisometropic hyperopia (range: +6.00 to +8.50 D) underwent unilateral iris-claw PIOL implantation from 2008 to 2018. The mean age was 6.7 years. The mean follow-up was 38.5 months. Target refraction was emmetropia.

RESULTS

The cycloplegic refraction (mean spherical equivalent) improved from -12.47 D (range: -9.25 to -18.50 D) to -0.73 D (range: +0.75 to -1.50 D) in myopic eyes and reduced from +7.15 D (range: +6.00 to +8.50 D) to +0.94 D (range: -0.50 to + 1.75 D) in hyperopic eyes. Eighty-four percent of eyes were corrected to within ±1.00 D of emmetropia. The mean uncorrected distance visual acuity (UDVA) improved from 1.74 ± 0.36 to 0.45 ± 0.28 logarithm of the minimum angle of resolution (logMAR) (P = .0014). The mean corrected distance visual acuity (CDVA) changed from 0.68 ± 0.32 to 0.27 ± 0.15 logMAR (P = .02179). The safety index was 2.18 and the efficacy index was 1.51. The mean pre-operative endothelial cell count of 2,874.7 cells/mm² changed to 2,685.3 cells/mm² at 2 to 6 years postoperatively. Binocular vision quality was improved in 55 patients. No patient had serious complications or lost any Snellen lines of CDVA.

CONCLUSIONS

Iris-fixated PIOL implantation is an effective and safe method in the treatment of high anisome-tropic myopia and hyperopia and amblyopia in pediatric patients who are noncompliant with spectacles or contact lenses. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XX-XX.].

Refractive outcomes of implantable collamer lens implantation in 1212 eyes with suboptimal corrected distance vision acuity

Purpose: To analyze the factors related to corrected distance vision acuity (CDVA) after implantable collamer lens (ICL) implantation in patients with preoperative suboptimal CDVA.Methods: This retrospective study included patients with suboptimal preoperative CDVA (CDVA ≤20/25) who underwent ICL implantation (V4 or V4c). Preoperative and postoperative clinical evaluations included CDVA, uncorrected distance visual acuity (UDVA), and refraction.Results: A total of 1,212 eyes from 731 patients were identified. CDVA increased in 90.8% of the eyes after surgery. Among them, 57.5% of the eyes (697 eyes) gained more than one line. The preoperative LogMAR CDVA was 0.32 ± 0.23, which significantly improved to 0.13 ± 0.17 postoperatively (p < 0.001). There was no significant difference between ICL V4c and ICL V4 in the LogMAR UDVA, sphere, cylinder, SE, LogMAR CDVA, efficacy index, and safety index after surgery (p > 0.05). For eyes with full correction, the postoperative LogMAR CDVA =0.575 * preoperative LogMAR CDVA -0.061 (p < 0.001, R² = 0.53). For eyes with partial correction, the postoperative LogMAR CDVA =0.536 * preoperative LogMAR CDVA - 0.007 * SE - 0.196 (P < 0.001, R² = 0.55).Conclusion: ICL implantation can improve CDVA in eyes with suboptimal CDVA. This study provides the postoperative outcomes of eyes with different preoperative CDVA, which makes it convenient for surgeons to communicate with such patients before surgery.

Visual outcomes of photorefractive keratectomy in non-children with anisometropic amblyopia: One-year Follow-up Outcomes

OBJECTIVE

To evaluate the safety, efficiency, short term stability, and sensory results of photorefractive keratectomy (PRK) in anisometropic in non-compliant children with correction.

METHODS

Twelve eyes of 12 children with an age range: 6-17 years and anisometropic amblyopia who underwent PRK under general anesthesia to correct the dioptric difference between the eyes were included in this study. A complete ophthalmic assessment including refractive status, uncorrected and corrected distance visual acuity (UDVA & CDVA), and binocular vision status using the Worth 4-dot test and stereopsis were performed before and 1, 3, 6, and 12 months after PRK.

RESULTS

The mean preoperative CDVA was 0.34 ± 0.24 LogMAR which showed a statistically significant improvement at 12 months (0.20 ± 0.19, p = 0.024) after surgery compared to the preoperative assessment. (p = 0.003) The mean preoperative UDVA was 0.63 ± 0.24 LogMAR that increased to 0.44 ± 0.24, 0.32 ± 0.16, 0.25 ± 0.19, and 0.25 ± 0.19 LogMAR at 1, 3, 6, and 12 months after PRK, respectively. One to three lines improvement in UDVA and CDVA was seen in 10 (83.4%) and 8 eyes (66.7%); while one line UDVA and CDVA loss was seen in one (8.3%) and one (8.3%) eye and unchanged UDVA and CDVA was seen in 1 (8.3%) and 3 eyes (25%), respectively. The mean preoperative stereoacuity was 341.9 ± 245.7 s of arc, which significantly improved to 166.6 ± 87.5 s of arc 12 months after PRK. (p = 0.012).

CONCLUSION

PRK was an effective surgical alternative to improve visual acuity and stereopsis in anisometropic children who did not cooperate with conventional methods of amblyopia therapy.

Influence of Ocular Residual Astigmatism and Target-Induced Astigmatism on the Efficacy of the Implantation of a Toric Implantable Collamer Lens With Central Hole for Myopic Astigmatism Correction

Purpose

To investigate the effects of ocular residual astigmatism (ORA) and target-induced astigmatism (TIA) on the efficacy of toric implantable collamer lens (TICL) with central hole for myopic astigmatism correction.

Methods

Retrospective case series. One hundred and eighteen eyes implanted with a TICL (V4c) from 118 patients were included. Subjective refraction and corneal topography were examined preoperatively, at 1 and 12 months postoperatively. The eyes were divided into the low-ORA ( ≤ 0.5 D) and high-ORA (&gt;0.5 D) groups based on vector analysis, and into the low-TIA (≥0.75D and &lt;2 D) and the high-TIA (≥2 D and ≤ 4 D) groups according to preoperative refractive astigmatism. Correction index (CI) and index of success (IOS) were compared between different groups.

Results

All surgeries were uneventful, and no complications occurred during follow-up. At 1 and 12 months postoperatively, no significant differences were found in CI or IOS values between the high and low ORA groups, while significantly higher CI and lower IOS were detected in the high-TIA group than in the low-TIA group (P &lt; 0.05). No significant difference was found in CI between 1 and 12 months postoperatively in either group (P &gt; 0.05). However, significantly lower IOS was found at 12 months compared with 1 month postoperatively for each group (P &lt; 0.05).

Conclusions

Toric implantable collamer lens (TICL) implantation is effective in correcting myopic astigmatism and is more effective in eyes with high TIA, while ORA has a minor effect.

Three-Month Outcomes of Laser Vision Correction for Myopia and Hyperopia in Adults With Amblyopia

PURPOSE

To evaluate the visual outcomes of laser vision correction in adults with myopic and hyperopic amblyopia.

METHODS

The medical records of patients diagnosed as having amblyopia who underwent laser refractive surgery between February 2013 and October 2017 were retrospectively reviewed. Eyes with amblyopia were analyzed, and the nonamblyopic fellow eyes of the patients who underwent laser vision correction were used as controls. The uncorrected distance visual acuity (UDVA), subjective manifest refraction, and corrected distance visual acuity (CDVA) were analyzed at the 3-month postoperative time point.

RESULTS

This study included 323 eyes of 164 patients. All patients underwent laser in situ keratomileusis (90.1%, 291 eyes) or photorefractive keratectomy (9.9%, 32 eyes). Three months postoperatively, the manifest spherical equivalent was -0.07 ± 0.55 diopters (D) (range: -1.75 to +1.30 D) and -0.10 ± 0.54 D (range: -2.13 to +1.30 D) in the amblyopia group and fellow eye group, respectively. The percentage of eyes achieving UDVA of 20/20 or better was 16.9% (15 eyes) in the amblyopia group and 61.9% (52 eyes) in the fellow eye group. The percentage of eyes that gained two or more lines of CDVA was 27.9% (24 eyes) in the amblyopia group and 6.2% (5 eyes) in the fellow eye group (P < .01). In the amblyopia group, there was no statistically significant difference in the mean manifest spherical equivalent between the myopic eyes and hyper-opic eyes at any follow-up visit (P = .87, 1 month postoperatively; P = .68, 3 months postoperatively).

CONCLUSIONS

Laser vision correction was found to be effective and safe in adult patients with amblyopia. [J Refract Surg. 2020;36(8):511-519.].

Posterior chamber phakic intraocular lens for the correction of high myopic anisometropic amblyopia in adults

This study aims to evaluate the clinical results of posterior chamber implantable collamer lens (ICL) implantation in adults with high myopic anisometropic amblyopia. Thirteen patients aged 27.04±7.24y (range 19.2 to 42.5) were studied. ICL implantation was performed in 13 amblyopic eyes. The mean myopic anisometropia was significantly dropped from -10.70±3.02 D preoperatively to +0.09±1.67 D at 1mo postoperatively. The logMAR CDVA at 3d, 1, 3 and mean 9mo postoperatively improved by a mean of 1.69, 2.50, 3.01 and 3.00 lines and gained more than 2 lines accounted for 23.08% (3 eyes), 41.67% (5 eyes), 63.63% (7 eyes) and 55.56% (5 eyes), respectively. The contrast sensitivity of amblyopic eyes was significantly increased after surgery. Four patients partially recovered near stereopsis (400″ to 100″). There was no severe complications were observed. ICL implantation alone can improve vision, contrast sensitivity, and partial restoration of binocular vision in adult patients with high myopic anisometropia.

Visual outcomes in adult amblyopic eyes with moderate myopia after corneal laser surgery versus copolymer phakic intraocular lens implant

PURPOSE

To assess visual acuity and refractive correction in moderately myopic adult eyes with suboptimal preoperative corrected distance visual acuity (CDVA) after laser in situ keratomileusis (LASIK) or insertion of a posterior chamber Implantable Collamer Lens phakic intraocular lens (pIOL).

SETTING

Clínica Baviera, Instituto Oftalmológico Europeo, Torrevieja Hospital, Madrid, Spain.

DESIGN

Retrospective study.

METHODS

The study sample included 1310 eyes that had LASIK and 94 that had insertion of a pIOL from July 2002 to September 2013. Suboptimal preoperative CDVA was defined as equal to logMAR 0.15 or below and moderate myopia as a spherical equivalent of -5.0 to -10.0 diopters (D).

RESULTS

The preoperative mean CDVA was 0.22 logMAR ± 0.09 (SD) in the LASIK group and 0.23 ± 0.09 logMAR in the pIOL group. Postoperative uncorrected distance visual acuity (UDVA) was 0.13 ± 0.12 logMAR in the laser group and 0.12 ± 0.09 logMAR in the pIOL group, with a postoperative CDVA of 0.11 ± 0.10 logMAR and 0.08 ± 0.07 logMAR, respectively.

CONCLUSIONS

Compared with preoperative values, amblyopic eyes with moderate myopia having LASIK or implantation of a pIOL demonstrated a statistically significant improvement in UDVA and CDVA (P < .001). The pIOL group performed significantly better than the LASIK group in terms of safety and efficiency.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Phakic intraocular lens explantation: causes in 240 cases

PURPOSE

To describe the main causes of explantation of phakic intraocular lenses (PIOLs) according to the anatomical site of implantation (angle supported, iris fixated, or posterior chamber).

METHODS

This multicentric, retrospective, and consecutive study sponsored by the Spanish Ministry of Health comprised a total of 240 eyes (226 patients) explanted due to PIOL complications. Clinical data of 144 angle-supported lenses, 24 iris-fixated lenses, and 72 posterior chamber lenses explanted were recorded preoperatively and postoperatively.

RESULTS

Mean age of the patients at explantation was 46.30 ± 11.84 years (range: 25 to 80 years). The mean time between implantation and explantation was 381.14 ± 293.55 weeks (range: 0.00 to 1,551.17 weeks). It was 422.33 ± 287.81 weeks for the angle-supported group, 488.03 ± 351.95 weeks for the iris-fixated group, and 234.11 ± 4,221.60 weeks for the posterior chamber group. It was 8.10 ± 5.52 years for the angle-supported group, 9.36 ± 6.75 years for the iris-fixated group, and 4.49 ± 4.25 years for the posterior chamber group. This period of time was significantly shorter in the posterior chamber group (P < .001). Overall, the main causes of explantation were cataract formation (132 eyes, 55%), endothelial cell loss (26 eyes, 10.83%), corneal decompensation (22 eyes, 9.17%), PIOL dislocation/decentration (16 eyes, 6.67%), inadequate PIOL size or power (12 eyes, 5%), and pupil ovalization (10 cases, 4.17%). Cataract development was the cause of explantation in 51.39% of angle-supported cases, 45.83% of iris-fixated cases, and 65.28% of posterior chamber cases. Endothelial cell loss was the cause of explantation in 15.97% of angle-supported PIOLs, 8.33% of iris-fixated PIOLs, and 1.39% of posterior chamber PIOLs.

CONCLUSIONS

Cataract is the main cause of PIOL explantation, especially in posterior chamber PIOLs. In the angle-supported group, endothelial cell loss was the second cause of explantation.

Pre-operative visual evaluation for implantable collamer lenses in highly myopic eyes

PURPOSE

The aim of this study was to evaluate a clinical procedure based on trial rigid gas-permeable (RGP) contact lenses fitting to assess the real pre-operative visual acuity (VA) of highly myopic eyes undergoing surgery with an implantable collamer lens.

METHODS

Highly myopic eyes with a spectacle visual acuity (SVA) of 0.2 logMAR (6/9.6 Snellen) or worse were enrolled. A trial RGP contact lens with high dioptric power was fitted before collamer lens implantation. The trial contact lens residual refractive error was corrected by spectacle over-refraction to estimate contact lens VA (CLVA). The three-month post-operative uncorrected vision and visual acuities were also measured. The safety and efficacy indices of collamer lens implantation were calculated based on pre-operative SVA and CLVA, respectively.

RESULTS

The study enrolled 42 patients with 68 highly myopic eyes with a mean pre-operative spherical equivalent of -16.40 ± 4.43 D. The mean pre-operative SVA was 0.38 ± 0.19 logMAR. Pre-operative trial RGP contact lens fitting resulted in a significant improvement of VA (2.02 ± 1.05 lines), which was statistically insignificantly different from the VA with the implantable collamer lens (2.07 ± 0.8 lines). The safety index of collamer lens implantation was 1.70 ± 0.38 in reference to the pre-operative SVA but significantly decreased to 1.02 ± 0.17 in reference to CLVA. Similarly, the efficacy index of 1.17 ± 0.48 on SVA decreased to 0.71 ± 0.28 on CLVA.

CONCLUSIONS

Trial RGP contact lens fitting was found to indicate the potential implantable collamer lens VA more accurately than spectacle refraction. Consideration should be given to the use a trial RGP contact lens as part of the pre-operative work-up prior to collamer lens implantation in order to provide an assessment of the patient's potential post-operative VA.

Posterior chamber phakic intraocular lens to correct myopia: long-term follow-up

PURPOSE

To evaluate the long-term safety and efficacy of a refractive phakic intraocular lens (pIOL) (PRL) to correct moderate to high myopia.

SETTING

Department of Ophthalmology, University Medicine Charité Berlin, Berlin, Germany.

DESIGN

Retrospective cohort study.

METHODS

Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure, endothelial cell loss, and adverse events were evaluated.

RESULTS

The study enrolled 53 eyes (mean spherical equivalent [SE] -12.17 diopters [D] ± 4.12 [SD]) of 29 patients. The mean age was 34.6 ± 9.2 years and the mean follow-up, 86 ± 21.2 months. The mean UDVA improved from 1.37 ± 0.28 logMAR preoperatively to 0.14 ± 0.19 logMAR at the last postoperative visit (P<.05). The mean CDVA improved from 0.10 ± 0.18 logMAR to -0.01 ± 0.09 logMAR (P<.05). The overall mean efficacy index and mean safety index were 0.9 and 1.21, respectively, at the last follow-up visit. The mean endothelial cell loss at the last follow-up was 6.4%. The complications were slight posterior chamber (PC) pIOL decentration (5 eyes, 9.4%), severe PC pIOL decentration resulting in pIOL removal (1 eye, 1.8%), glaucoma (4 eyes, 7.5%), clinically significant cortical lens opacification resulting in cataract surgery (4 eyes, 7.5%), clinically asymptomatic anterior subcapsular cataract formation (6 eyes, 11.3%), and retinal detachment (2 eyes, 3.8%).

CONCLUSIONS

Posterior chamber phakic pIOL implantation to correct moderate to high myopia provided predictable and stable refractive results but with a high rate of serious complications over the long term.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Toric implantable collamer lens for moderate to high myopic astigmatism: 3-year follow-up

BACKGROUND

To evaluate the 3-year clinical outcomes after toric implantable collamer lens (ICL) implantation for the management of moderate to high myopic astigmatism.

METHODS

Thirty-four eyes of 20 patients who underwent toric ICL implantation were reviewed. All eyes completed 3-year follow-up. Uncorrected (UDVA) and corrected (CDVA) distance LogMAR visual acuities, refraction, endothelial cell density (ECD), and surgical complications were evaluated. Vectorial analysis of astigmatic correction was also done.

RESULTS

A significant improvement in UDVA, CDVA, manifest spherical and cylindrical refraction was observed at 1 week and remained stable after 3 years. Twenty-six eyes (76.5%) gained lines of CDVA, and two eyes (5.9%) showed a loss of 1 line of CDVA. The spherical equivalent (SE) was within ±0.50 D of emmetropia in 18 eyes (52.9%) and within ±1.00 D in 28 eyes (82.4%). Differences between target-induced astigmatism (TIA) and surgically-induced astigmatism (SIA) were statistically significant (p < 0.01), and a trend to undercorrection of the refractive astigmatism was present after 3 years. The magnitude of flattening effect (FE) was found to be significantly lower than the magnitude of TIA (p < 0.01). The magnitude of the torque vector was always positive, with a value below 0.50 D in all cases. No vision-threatening complications were observed during the follow-up.

CONCLUSION

Toric ICL implantation is an effective and safe surgical option that provides a relatively predictable and stable refractive correction of myopic astigmatism. Further improvements are needed to minimize the degree of undercorrection.

Preliminary in vivo positional analysis of a posterior chamber phakic intraocular lens by optical coherence tomography and its correlation with clinical outcomes

Purpose

To analyze by spectral-domain optical coherence tomography the anatomical relationship of a specific type of posterior chamber phakic intraocular lens (pIOL) implanted in cases of high to moderate myopia with the adjacent intraocular structures and to correlate it with clinical outcomes.

Methods

Prospective observational case series including 18 eyes with high to moderate myopia (spherical equivalent between −5.88 and −15.75 D) of 9 patients (age range, 29–49 years) undergoing bilateral Phakic Refractive Lens (PRL, Zeiss) implantation. Postoperative visual acuity, refraction, contrast sensitivity (CS), and ocular higher order aberrations (HOA) were evaluated. Furthermore, the in vivo position of the PRL was analyzed by means of spectral domain optical coherence tomography (3D OCT-1000, Topcon). Central (CENV), temporal (TEMV) and nasal vault (NASV) were measured. Correlation of these anatomical parameters with clinical data was also investigated. Mean follow-up was 47 ± 25 months.

Results

A statistically significant visual and refractive improvement (p < 0.01) was found postoperatively. Mean postoperative CENV, NASV, and TEMV were 157.88 ± 69.93 μm, 168.29 ± 65.02 μm, and 188.59 ± 55.99 μm, respectively. Significant difference was found between NASV and TEMV (p = 0.01). No significant correlations were found between ocular aberrometric and anatomical parameters (p ≥ 0.12). CENV, NASV and TEMV correlated significantly with 6-cycles per degree (cpd) photopic CS as well as with 18-cpd low mesopic CS (r ≥ 0.57, p ≤ 0.04). Furthermore, NASV also correlated significantly with preoperative anterior chamber depth (r = −0.65, p = 0.01).

Conclusions

This posterior chamber pIOL shows a trend to nasal position, with potential impact on refractive and visual outcomes, particularly in eyes with deep anterior chambers.

Medium-term visual, refractive, and intraocular stability after implantation of a posterior chamber phakic intraocular lens to correct moderate to high myopia

PURPOSE

To evaluate the medium-term refractive and visual outcomes and the complications after implantation of a silicone posterior chamber phakic intraocular lens (PC pIOL) for moderate to high myopia.

SETTING

Oftalmar, Medimar International Hospital, Alicante, Spain.

DESIGN

Retrospective case series.

METHODS

Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and intraocular pressure were evaluated during a medium-term follow-up. Postoperative complications were also studied.

RESULTS

The study enrolled 35 eyes (mean preoperative spherical equivalent [SE] -10.25 diopters [D] ± 3.19 [SD]) of 20 patients with a mean age of 31.83 ± 8.87 years and a mean follow-up of 57.34 ± 9.24 months. The mean UDVA improved from 2.40 ± 0.20 logMAR preoperatively to 0.08 ± 0.13 logMAR at the last postoperative visit (P<.01). The mean CDVA improved from 0.11 ± 0.09 logMAR to 0.02 ± 0.09 logMAR, respectively (P<.01). The postoperative CDVA was 0.1 or better in 30 eyes (85.71%), with 22 eyes (62.86%) gaining lines of CDVA. The final efficacy index was 1.16 and the final safety index, 1.26. Regarding predictability, 34 eyes (97.14%) had an SE within ± 1.00 D and 33 eyes (94.28%) within ± 0.50 D. The complications were PC pIOL decentration (2 eyes, 5.71%), cortical lens opacification (1 eye, 2.86%), and retinal detachment (1 eye, 2.86%).

CONCLUSIONS

Implantation of a PC pIOL to correct moderate to high myopia was efficient and predictable in the medium term, with intraocular stability in most cases. New designs and criteria for PC pIOL size selection should be developed.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Collagen copolymer toric posterior chamber phakic intraocular lens in eyes with keratoconus

PURPOSE

To assess the safety, efficacy, stability, and predictability of collagen copolymer toric phakic intraocular lens (pIOL) implantation to correct myopia and astigmatism in eyes with keratoconus.

SETTING

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

METHODS

This prospective study comprised keratoconic eyes that had implantation of a toric Intraocular Collamer Lens. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and postoperative complications were evaluated 1, 3, 6, and 12 months postoperatively.

RESULTS

Preoperatively, the mean spherical equivalent in the 30 eyes (21 patients) was -5.38 diopters (D) +/- 3.26 (SD) (range -13.50 to -0.63 D) and the mean cylinder, -3.48 +/- 1.24 D (range -1.75 to -6.00 D). At 12 months, 86.7% of the eyes were within +/-0.50 D of the attempted refraction and all eyes were within +/-1.00 D. For the astigmatic components J0 and J45, 83.3% of eyes and 86.7% of eyes, respectively, were within +/-0.50 D. The mean Snellen UDVA was 0.81 +/- 0.20 and the mean CDVA, 0.83 +/- 0.18; CDVA was 20/40 or better in 29 eyes 96.7% of eyes and 20/25 or better in 22 eyes (73.3%). No eyes lost more than 2 lines of CDVA; 29 eyes (96.7%) maintained or gained 1 or more lines. The efficacy index was 1.07 and the safety index, 1.16. There were no complications or adverse events.

CONCLUSIONS

The results confirm that toric ICL implantation is a predictable, effective procedure to correct ametropia in eyes with keratoconus. Predictability and stability were achieved early and remained fairly stable up to 12 months.

Refractive stability of LASIK with the Visx 20/20 excimer laser vs ZB5m phakic iol implantation in patients with high myopia (>-10.00 d): a 10-year retrospective study

PURPOSE

To compare the long-term outcomes of LASIK and ZB5M phakic intraocular lens implantation (PIOL) (Domilens) for high myopia (>-10.00 diopters [D]).

METHODS

This long-term (10 years) follow-up retrospective interventional case series study included 126 eyes that underwent LASIK and 52 eyes that underwent ZB5M angle-supported PIOL implantation. Both groups of eyes were similar in terms of preoperative spherical equivalent refraction (SE), corrected distance visual acuity (CDVA), and age.

RESULTS

Mean preoperative SE was -14.33 D in the LASIK group and -14.84 D in the PIOL group. At 10-year follow-up, mean postoperative SE was -1.47±2.00 D in the LASIK group and -1.01±1.36 D in the PIOL group (P=.21). In the LASIK group, 67% of eyes were within ±1.00 D of emmetropia at 2 years after surgery, compared to 42% at 10 years. In the PIOL group, 68% of eyes were within ±1.00 D of emmetropia 2 years after implantation compared to 53% at 10 years. In the LASIK group, 43.5% of eyes achieved UDVA of 20/40 or better 10 years after surgery compared to 67.9% in the PIOL group (P=.02).

CONCLUSIONS

The ZB5M angle-supported PIOL was shown to have better predictability and stability compared to LASIK over 10 years. However, reductions in endothelial cell count over time were observed in eyes with PIOLs.

LASIK correction of vision in adults with unilateral amblyopia

PURPOSE

to evaluate the effects of laser refractive surgery in adult patients with mild to moderate amblyopia due to anisometropic myopia.

METHODS

a retrospective review of 30 patients (60 eyes) with unilateral amblyopia (corrected distance visual acuity [CDVA] 0.6 or worse) who underwent simultaneous bilateral laser vision correction using the Technolas 217z excimer laser (Bausch & Lomb) was performed. Mean patient age was 31.03 ± 10.05 years (range: 18 to 53 years). Visual outcomes in the amblyopic eye were compared with those in the fellow nonamblyopic control eye of the same patient.

RESULTS

mean preoperative CDVA improved in amblyopic eyes from 0.50 ± 0.13 to 0.57 ± 0.20 postoperatively (average gain of 0.075 ± 0.14; P=.007) and improved from 0.92 ± 0.12 preoperatively to 0.93±0.15 after surgery (mean gain of 0.013 ± 0.14; P=.603) in the fellow nonamblyopic eyes. The safety index was significantly greater in the amblyopic eyes compared with the nonamblyopic fellow eyes (1.15 ± 0.30 vs 1.02 ± 0.15, P=.035), therefore, no difference was noted in efficacy (P=.913). Five of 30 eyes with mild to moderate amblyopia gained 2 to 4 lines of CDVA.

CONCLUSIONS

laser refractive surgery for myopic correction was found to be safe and effective in eyes with mild to moderate amblyopia.

Corneal Higher-Order Aberrations in Amblyopia

Purpose

To investigate the amount, type, and role of corneal higher order aberrations in both isotropic and anisometropic amblyopic adult patients.

Methods

A total of 125 eyes of 78 patients with age ranging from 18 to 67 years (30 patients with unilateral amblyopia, 17 with bilateral amblyopia, and 31 normal eyes considered as the control group) were included. All eyes received a comprehensive ophthalmologic examination that included corneal topographic and aberrometric analysis with the CSO system. The aberrometric study was performed for a 6-mm pupil using different root mean square (RMS) parameters. Additionally, the ocular residual astigmatism (ORA) was also calculated and analyzed. A comparative analysis of the refractive and aberrometric data between groups was performed.

Results

In the unilateral amblyopia group, statistically significant differences between the amblyopic and non-amblyopic eye were found in cylinder (p=0.003), best-corrected visual acuity (BCVA) (p<0.001), total RMS (p=0.015), and astigmatic RMS (p=0.019). Statistically significant differences between the bilateral amblyopia and control groups were observed in sphere (p=0.025), cylinder (p=0.005), and BCVA (p <0.001). When comparing isometropic and anisometropic bilateral amblyopic eyes, significant differences in total (p=0.025) and astigmatic RMS (p=0.013) were detected. Higher but nonsignificant amounts of primary coma were found in isometropic eyes (0.25 μm anisometropic vs 0.43 μm isometropic, p=0.09). Regarding the ORA, no significant differences between groups were found (p≥0.224).

Conclusions

In unilateral and bilateral amblyopia, lower order aberrations are the main refractive factors leading to amblyopia. Higher order aberrations could have a bilateral amblyogenic effect in those cases where isometropia is present.

Can uncompensated higher order aberration profile, or aberropia be responsible for subnormal best corrected vision and pseudo-amblyopia

BACKGROUND

Higher order aberrations (HOA) are components of wavefront distortion which cannot be corrected by conventional spectacle correction. Normally they constitute up to 15% of wavefront distortion in the ocular media. The HOA interact in a nonlinear method and tend to compensate each other in most conditions.

HYPOTHESES

We hypothesize that abnormally increased and uncompensated higher order aberration profile in certain cases may limit the amount of best corrected visual acuity to subnormal levels and produce a pseudo-ambylopia like picture. We term this entity as aberropia.

EVALUATION OF THE HYPOTHESIS

Higher order aberrations (HOA) have been proven to have supporting role in visual function in association with lower order aberrations. Normally HOA tend to compensate for each other and have an effect much less than what would be expected if they would have acted separately. This unique state of compensation may be lost in certain cases, for example, in patients who have undergone laser refractive surgery without consideration for HOA correction or in partial correction of a pathological eye like severe keratoconus. Occasionally investigators have noticed that patients with high induced aberrations after refractive surgery cannot achieve spectacle correction to get a 20/20 vision. Conversely, there is evidence for gain of vision after wavefront guided refractive surgery and phakic intraocular lens implantations in some cases which cannot be explained only by retinal image change.

CHALLENGES TO CONCLUSIVELY PROVE THE HYPOTHESES

With the current level of advancement in refractive surgery, we can correct lower order aberration to a near zero level. However it is not as easy to do the same with higher order aberrations because of variability in assessment, evolving laser beam profiles and factors associated with the surgery itself and wound healing. All the four can alter higher order aberrations.

IMPLICATIONS OF THE HYPOTHESES

Understanding of uncompensated higher order profiles leading to loss of BCVA, or aberropia, would be a paradigm shift in understanding of the role of higher order aberrations on visual function. With improvement in diagnostic and treatment methods, these patients with a subnormal vision, may be treated to achieve their maximum visual potential.