Complete bilateral vitreous detachment after LASIK retreatment

Intraocular pressure changes before and after a femtosecond laser procedure for cataract surgery

This study aimed to evaluate the changes in intraocular pressure (IOP) before and after femtosecond laser capsulorhexis and lens fragmentation for cataract surgery. We measured the IOP before, immediately, 30 min, and 1 h after the laser procedure in 47 eyes of 47 patients who underwent the femtosecond laser procedure. The mean IOP was 17.51 ± 3.28 mmHg, 30.23 ± 6.70 mmHg, 17.96 ± 3.75 mmHg, and 21.77 ± 5.88 mmHg before, immediately after, 30 min after, and 1 h after the laser procedure, respectively. The mean IOP significantly increased immediately (adjusted P < 0.001) and 1 h (adjusted P = 0.001) after the laser procedure compared with the pre-laser IOP. The mean IOP at 30 min after the laser procedure was significantly lower than that immediately after the procedure (adjusted P < 0.001). However, the IOP 1 h after the laser procedure became higher than that 30 min after the laser procedure. Additionally, the IOP 1 h after the laser procedure was positively correlated with the baseline IOP and negatively correlated with the axial length. In conclusion, this study demonstrated that cataract surgery should be commenced within 30 min after the femtosecond laser procedure to ensure a safe cataract surgery that reduces the risk of increased intraocular pressure.

Distinct macular thickness changes after femtosecond laser-assisted cataract surgery of age-related cataract and myopia with cataract

Cataract surgery can cause macular thickness change. We used optical coherence tomography (OCT) to assess the macular thickness of different regions after femtosecond laser–assisted cataract surgery of age-related cataracts (ARC) and myopia cases with cataract (myopia group). Fifty eyes of 50 patients in ARC group and fifty eyes of 50 patients in myopia with cataract group were included. All study underwent femtosecond laser–assisted cataract surgery and macular thickness of was measured at pre-operation and 1 week, 1 month after surgery. There are significant differences of foveal thickness (P = 0.02), foveal volume (P = 0.02) and average retinal thickness (P = 0.02) between two groups before operation. In the myopia group, statistically significant differences were not found in postoperative macular thickness as compared with ARC group. There are differences in macular thickness between pre-operation and 1 month after operation when compared with nasal outer macular ring thickness (P = 0.022), foveal volume (P = 0.005) and average retinal thickness (P = 0.012) in ARC group. The study suggest that femtosecond laser–assisted cataract extraction is safe in myopia group that did not cause significant increase of macular thickness. However, an increased post-operative local macular thickness was recoded while comparing macular thickness with the baseline in ARC group.

[Hybrid (femtosecond laser-assisted) phaco surgery and the state of the macula]

The review covers different aspects of the impact of femtosecond laser-assisted cataract surgery on the state of the macular zone of the retina. Literature search has revealed inconsistency of the published data and indicated the need for a more detailed study of this problem.

Retinal detachment after laser in situ keratomileusis

Purpose:

To report characteristics and outcome of rhegmatogenous retinal detachment (RRD) after laser in situ keratomileusis (LASIK) for myopia.

Materials and Methods:

A retrospective chart review of patients who presented with RRD after myopic LASIK over a 10-year period.

Results:

Fourteen eyes were identified with RRD. Of these, two of 6112 LASIK procedures were from our center. The mean age of patients with RRD was 35.43 years. The mean interval of RRD after LASIK was 37.71 months (range, 4 months to 10 years). The macula was involved in eight eyes and spared in six eyes. Retinal breaks included a macular hole in two eyes, and giant tear in two eyes. Multiple breaks (>2 breaks) occurred in 6 cases. Pars plana vitrectomy (PPV) was performed in 3 (21.4%) eyes, a scleral buckle (SB) was performed in 4 (28.5%) eyes and 7 (50%) eyes underwent combined PPV and SB. Mean follow-up was 15.18 months (range, 1 month to 7 years). The retina was successfully attached in all cases. The final visual acuity was 20/40 or better in 7 (50%) eyes, 20/40 to 20/60 in 4 (28.5%) eyes, and 20/200 or less in 3 (21.4%) eyes. Poor visual outcome was secondary to proliferative vitreoretinopathy, epiretinal membrane, macular scar and amblyopia.

Conclusion:

The prevalence of RRD after LASIK was low at our institute. Anatomical and visual outcomes were acceptable in eyes that were managed promptly. Although there is no cause-effect relationship between LASIK and RRD, a dilated fundus examination is highly recommended before and after LASIK for myopia.

Importance of fundoscopy in refractive surgery

PURPOSE

To examine the incidence, treatment, and outcomes of retinal lesions before and after refractive laser surgery.

SETTING

Private refractive surgery practice.

METHODS

A retrospective review was conducted of patients attending the laser clinic over a 3-year period. Examined were the incidence, type, management, and outcomes of the posterior segment abnormalities encountered.

RESULTS

Fifty two (1.1%) of 4800 patients had posterior segment pathology requiring intervention. Forty-five cases (0.86%) were detected preoperatively and had a mean refraction of -4.5 diopters (D) +/- 3.0 (SD). Seven cases (0.14%) were detected postoperatively at a mean follow-up of 19 +/- 18.3 months; none had preoperative pathology. The mean refraction in this group was -4.4 +/- 2.3 D. Ninety-five percent had myopic prescriptions. All maintained best corrected visual acuity postoperatively. The incidence of retinal detachment was 0.03% per year in the myopic candidates; however, no cases occurred after the refractive procedure.

CONCLUSION

Dilated fundus examination is an integral part of optimum clinical care in refractive patients, and shared preoperative assessment by a retinal specialist is advisable in those with predisposing retinal pathology.

Ocular Structure Changes During Vacuum by the Hansatome Microkeratome Suction Ring

PURPOSE

To evaluate whether the vacuum of a microkeratome suction ring induces ocular structure changes.

METHODS

A prospective case series using A-scan ultrasonography to measure anterior chamber depth, lens thickness, vitreous body, and axial length was performed. Measurements before and during application of a Hansatome microkeratome suction ring were performed on 69 eyes of 39 consecutive patients scheduled to undergo a first-time LASIK procedure with mechanical creation of a corneal flap.

RESULTS

Mean patient age was 43 +/- 12.1 years. Of the 69 eyes, 63 (91.3%) had refractive myopia with a mean spherical equivalent refraction of -2.93 +/- 1.56 diopters (D) and 6 (8.7%) had refractive hyperopia with a mean spherical equivalent refraction of 1.37 +/- 0.31 D. Overall, the mean spherical equivalent refraction of all eyes was -2.56 +/- 1.94 D. Ultrasound measurements during suction revealed a decrease in the anterior chamber depth of -0.06 +/- 0.36 mm (P < .05) and lens thickness by -0.14 +/- 0.45 mm (P < .05) whereas the vitreous body increased 0.25 +/- 0.36 mm (P < .05). Although insignificant, a trend toward increasing axial length was noted. No measurements changed over time during the application of vacuum.

CONCLUSIONS

Vacuum by a microkeratome suction ring induced a compression of the anterior chamber and lens with commensurate expansion of the vitreous body. The assessment of vacuum effects during LASIK suggests that measurements of intraocular compartments are more informative than axial length.

Induction of posterior vitreous separation using LASIK suction ring may have a potential role in the management of diabetic macular edema

A significant percentage of patients with diabetic macular edema respond poorly to conventional laser photocoagulation. One associated factor in such patients with refractory diabetic macular edema is the absence of posterior vitreous detachment (PVD). Several invasive methods, such as surgical induction of PVD result in resolution of macular edema and improvement in visual acuity. Being invasive such modalities may have important surgical risks, such as retinal detachment and endophthalmitis. Recently, laser in situ keratomeilusis (LASIK), a well-accepted refractive procedure, has been reported to produce posterior vitreous detachment in patients with myopia. We herein hypothesize that application of LASIK suction ring, an external procedure, may be useful in the induction of PVD in patients with refractory diabetic macular edema and may have a better safety profile.