Differences in Axial Length and IOL Power Based on Alternative A-Scan or Fellow-Eye Biometry in Macula-Off Rhegmatogenous Retinal Detachment Eyes

Axial length adjustment in eyes with silicone oil endotamponade reduces overestimation by a swept-source optical coherence tomography-based biometer

BACKGROUND

To assess changes in ocular biometry of the phakic eye after pars-plana-vitrectomy (PPV) and silicone oil (SO) endotamponade in eyes with a retinal detachment.

METHODS

This retrospective, consecutive case series included 72 eyes of 72 patients who underwent PPV with 5000-centistokes SO endotamponade between July 2018 and June 2023. Pseudophakic eyes and eyes with a combined phacovitrectomy were excluded. Primary endpoints were keratometry values, anterior chamber depth (ACD), lens thickness (LT), horizontal corneal diameter (HCD), and axial length (AL) measured by swept-source optical coherence tomography-based biometry (IOLMaster 700) preoperatively and six weeks postoperatively. A recently described formula was used to adjust the AL (aAL) in eyes with SO endotamponade and a theoretical intraocular lens (IOL) calculation was performed.

RESULTS

The mean age was 62.1 ± 8.3 years (range: 37-85). After PPV with SO fill, there was an increase in Kmean (0.19 ± 0.51D), while ACD (0.05 ± 0.13 mm), LT (0.03 ± 0.14 mm), and HCD (0.02 ± 0.24 mm) decreased. Preoperatively, the mean AL was 25.22 ± 1.78 mm, while postoperatively the AL was overestimated by 0.12 ± 0.42 mm on average (p = 0.04). By adjusting the AL, the mean difference could be reduced to -0.002 ± 0.41 mm. The aAL resulted in a difference in the refractive outcome in eyes with an AL > 25 mm of 0.34 ± 0.10D in the IOL calculation.

CONCLUSIONS

While changes in biometry after PPV with SO endotamponade in the anterior segment are clinically less relevant, a considerable overestimation of AL with IOLMaster 700 was found. We recommend the use of a recently introduced formula for adjusting AL in eyes with SO, allowing overestimation to be minimised considerably.

Fellow eye data for intraocular lens calculation in eyes undergoing combined phacovitrectomy

PURPOSE

To evaluate whether the intraocular lens (IOL) calculation of the fellow eye (FE) can be used in eyes undergoing combined phacovitrectomy.

METHODS

In this retrospective, consecutive case series, we enrolled patients who underwent combined phacovitrectomy with silicone oil removal and IOL implantation at the Goethe-University. Preoperative examinations included biometry (IOLMaster 700; Carl Zeiss). We used the IOL calculation of the FE (FE group) to calculate the prediction error compared with the IOL calculation using only the axial length (AL) of the FE (AL-FE group), as well as using the AL of the operated eye (OE group) in addition to the measurable biometric parameters. IOL calculation was performed using the Barrett Universal II formula. We compared the mean (MAE) and median absolute prediction error (MedAE) with each other. Furthermore, the number of eyes with ±0.50, ±1.00 and ±2.00 dioptres (D) deviation from the target refraction was compared.

RESULTS

In total, 79 eyes of 79 patients were included. MedAE was lowest in the OE group (0.41 D), followed by FE group (1.00 D) and AL-FE group (1.02 D). Comparison between the AL-FE and FE groups showed no statistically significant difference (p = 0.712). Comparing eyes within ±0.50 D of the target refraction, the OE group (63.3%) performed best, followed by the AL-FE group (27.8%) and the FE group (26.6%).

CONCLUSION

Our results indicate no clinically relevant difference between using the IOL calculation of the FE versus using only the AL of the FE in addition to the measurable parameters for the IOL calculation. A two-step procedure should always be strived for.

Accuracy of using the axial length of the fellow eye for IOL calculation in retinal detachment eyes undergoing silicone oil removal

PURPOSE

Evaluate whether the axial length of the fellow eye can be used to calculate the intraocular lens (IOL) in eyes with retinal detachment.

DESIGN

Retrospective, consecutive case series.

METHODS

Our study was conducted at the Goethe University and included patients who underwent silicone oil (SO) removal combined with phacoemulsification and IOL implantation. Preoperative examinations included biometry (IOLMaster 700, Carl Zeiss). We measured axial length (AL) of operated eye (OE) or fellow eye (FE) and compared mean prediction error and mean and median absolute prediction error (MedAE) using four formulas and AL of the OE (Barrett Universal II (BUII)-OE). Additionally, we compared the number of eyes within ±0.50, ±1.00 and ±2.00 dioptre (D) from target refraction.

RESULTS

In total, 77 eyes of 77 patients met our inclusion criteria. MedAE was lowest for the BUII-OE (0.42 D) compared with Kane-FE (1.08 D), BUII-FE (1.02 D) and Radial Basis Function 3.0 (RBF3.0)-FE (1.03 D). This was highly significant (p<0.001). The same accounts for the number of eyes within ±0.50 D of the target refraction with the BUII-OE (44 eyes, 57%) outperforming the RBF3.0-FE (20 eyes, 25.9%), Kane-FE and BUII-FE formula (21 eyes, 27.2%) each.

CONCLUSION

Our results show a statistically and clinically highly relevant reduction of IOL power predictability when using the AL of the FE for IOL calculation. Using the AL of the SO filled eye after initial vitrectomy results in significantly better postoperative refractive results. A two-step procedure using the AL of the OE after reattachment of the retina is highly recommended.

Accuracy of ultrasound vs. Fourier-domain optic biometry for measuring preoperative axial length in cases of rhegmatogenous retinal detachment

PURPOSE

To identify a method for accurately measuring preoperative axial length (AL) in cases of rhegmatogenous retinal detachment (RRD).

STUDY DESIGN

Retrospective study.

METHODS

This retrospective study included 83 eyes of 83 patients who underwent vitrectomy for RRD and had both preoperative and postoperative data for AL. Preoperative AL measurements for the affected eye were obtained using ultrasound (aUS-AL) and compared with those for affected and fellow eyes measured using optical biometry (aOB-AL and fOB-AL, respectively). Absolute differences between preoperative aUS-AL, aOB-AL, or fOB-AL measurements and postoperative AL (aPost-AL) were examined.

RESULTS

In the 41 eyes without macular detachment, the absolute difference between aOB-AL and aPost-AL (0.06±0.07 mm) was significantly smaller than between aUS-AL and aPost-AL (0.21±0.18 mm) and that between fOB-AL and aPost-AL (0.29±0.35 mm) (P = 0.017 and P < 0.001, respectively). In the 42 eyes with macular detachment, the absolute difference between aOB-AL and aPost-AL (1.22±2.40 mm) was significantly larger than between aUS-AL and aPost-AL (0.24±0.24 mm) and between fOB-AL and aPost-AL (0.35±0.49 mm) (P = 0.006, P = 0.016, respectively).

CONCLUSION

The current findings suggest that aOB-AL is more accurate than aUS-AL or fOB-AL in cases of RRD without macular detachment, while aUS-AL or fOB-AL is more accurate than aOB-AL in cases with macular detachment.

Intraocular Lens Calculation Using 8 Formulas in Silicone Oil-Filled Eyes Undergoing Silicone Oil Removal and Phacoemulsification After Retinal Detachment

PURPOSE

To evaluate formulas for intraocular lens (IOL) calculation in silicone oil (SO)-filled eyes.

DESIGN

Retrospective, consecutive case series.

METHODS

We conducted our study at the Department of Ophthalmology, Goethe University, Frankfurt, Germany, and included SO-filled eyes that received SO removal combined with phacoemulsification and IOL implantation. Preoperative assessments included biometry (IOLMaster 700; Carl Zeiss Meditec). To evaluate the measurements, we compared the mean prediction error, and mean and median absolute prediction error of 8 different formulas.

RESULTS

A total of 90 eyes matched our inclusion criteria. The median absolute error was lowest in the Barrett Universal II formula (0.43 diopters [D] ± 0.75) followed by Kane (0.44 D ± 0.75), Hill-radial basis function (0.47 D ± 0.74), Holladay II (0.47 D ± 0.77), Sanders Retzlaff Kraff/theoretical (0.51 D ± 0.74), Holladay I (0.51 D ± 0.76), and Haigis and Hoffer Q (0.52 D ± 0.74 each). Regarding eyes within ±0.5 D Barrett Universal II (57.8%, 52 eyes) performed best, again followed by Kane (56.7%, 51 eyes) and Hill-radial basis function (54.4%, 49 eyes).

CONCLUSION

Using modern formulas for IOL calculation in oil-filled eyes improves predictability but still not as good as in unoperated eyes. This issue is created by the change in refractive index due to the SO fill and therefore a lower precision of axial length measurement and effective lens position prediction.

Simultaneous Management of Retinal Detachment and Aphakia with Pars Plana Vitrectomy, Silicone Oil Tamponade and Retropupillary Iris-Claw Intraocular Lens Implantation in These Cases

BACKGROUND

Marfan Syndrome is an autosomal dominant disease with multiple ocular abnormalities including ectopia lentis and a high incidence of rhegmatogenous retinal detachment (RRD). The management of RRD may be challenging in cases of aphakic patients with Marfan.

PURPOSE

To report on the management of four cases of simultaneous RRD and aphakia with vitrectomy, silicone oil tamponade, and retropupillary iris-claw intraocular lens (IOL) implantation in patients with Marfan that have been operated at the Jules-Gonin Eye Hospital between 2019 and 2020.

HISTORY AND SIGNS

Ages at presentation were 20, 30, 32, and 31 years, respectively. All patients had a history of extraction of a dislocated lens. None of the patients had a previous posterior vitrectomy. Two patients had records of previous measurements for IOL calculation by optical biometry (IOL Master, Carl Zeiss Meditec AG, Jena, Germany) about 1 year prior to the RRD development. In two cases, measurements for IOL calculation by optical biometry were based on the contralateral eye.

THERAPY AND OUTCOME

All patients underwent 23 G vitrectomy, peripheral iridotomy, and retropupillary iris-claw IOL. No intraoperative complications were encountered. All patients had silicone oil tamponade, one of which required heavy silicone oil. Silicone oil was removed 3 months following primary surgery. Minimum follow-up was 1 year. The single surgery anatomic success rate was 100%. All patients had visual acuity of at least 0.8 at the last follow-up (1.25, 1.0, 0.8, and 0.8 respectively). The targeted refractive results were accurately achieved in all four cases postoperatively. One patient presented ocular hypertension 2 weeks after surgery due to presumed steroid response and was managed conservatively. None of the patients had silicone oil migration into the anterior chamber.

CONCLUSION

Retropupillary iris-claw IOL implantation in cases of RRD and aphakia creates a barrier to tamponades from the posterior segment, effectively preventing them from entering the anterior segment of the eye. Therefore, the management of aphakia and retinal detachment with simultaneous vitrectomy and a retropupillary iris-claw IOL may be a successful strategy in reducing postoperative complications in patients with Marfan syndrome.