Scleral expansion bands for presbyopia1

Objective

To evaluate the safety and effectiveness of surgery using scleral expansion bands.

Imaging scleral expansion bands for presbyopia with optical coherence tomography

A 57-year-old woman was treated for mild presbyopia with implantation of scleral expansion bands (SEB). Although near vision was temporarily restored, the effect dissipated after 1 year. Slitlamp-adapted optical coherence tomography (OCT) at 1310 nm allowed precise cross-sectional visualization of the hyporeflective intrascleral segments. The OCT method provided precise images of the segment depth and thickness, the scleral thickness at the scleral spur, the anterior chamber angle, and the angle-opening distance. Intrascleral tilting of 1 segment was seen; this required removal of the SEB because of marked foreign-body sensation. Noncontact, slitlamp-adapted OCT can be used to evaluate scleral changes after SEB implantation.     

Scleral expansion surgery does not restore accommodation in human presbyopia.

OBJECTIVE: To determine the efficacy of scleral expansion surgery in the treatment of human presbyopia. DESIGN: Experimental study. PARTICIPANTS: Three preoperative presbyopic subjects, three postoperative presbyopic subjects, and three young control subjects. METHODS: Accommodative responses were recorded by an infrared dynamic optometer while subjects viewed an accommodative stimulus that stepped from 0 to 4 diopters in 1-diopter steps. MAIN OUTCOME MEASURES: Dynamic infrared optometer recordings of accommodation. RESULTS: Presbyopic patients showed no evidence of accommodation after scleral expansion surgery. CONCLUSIONS: If presbyopic patients read smaller letters at near after scleral expansion surgery than they were able to read prior to the surgery, then an explanation other than the restoration of accommodation needs to be found.     

A complication of scleral expansion surgery for treatment of presbyopia

PURPOSE: To report a patient who developed complications from an experimental technique using scleral expansion to treat presbyopia. METHODS: Case report of a 46-year-old woman who underwent scleral expansion surgery on her right eye. Postoperatively, the patient developed chronic pain and swelling that necessitated removal of the scleral expanders. RESULTS: After removal of the scleral expanders, the patient demonstrated a -1.4 diopter myopic shift in the right eye relative to her preoperative refraction. Axial length of the right eye was 1.15 mm longer than of the left, whereas preoperative axial lengths were equal. CONCLUSION: This patient developed scleral thinning with resultant axial lengthening and myopic shift, akin to the phenomenon observed with scleral buckles used to treat retinal detachments. We believe this was responsible for improved near vision in her right eye, rather than any increased accommodative potential purported to result from this operation.     

Implantation of scleral expansion band segments for the treatment of presbyopia

PURPOSE: To assess the effects of scleral expansion band (SEB) segments on accommodative amplitude (primary measure), along with near and distance vision, refraction, pupil size and function, keratometry, axial length, intraocular pressure, contrast sensitivity, stereopsis, and other parameters (secondary measures) in a cohort of 29 emmetropic, presbyopic patients. DESIGN: Multicenter, prospective, nonrandomized, unmasked clinical trial in which the nonoperated eye served as the control. METHODS: Four polymethylmethacrylate segments were surgically implanted in quadrantic scleral pockets created in the dominant eye of 29 emmetropic patients who were between the ages of 51 and 60 (mean age 54). Patients were examined preoperatively and up to 6 months postoperatively. The aforementioned tests were performed on the operated and control eye of each patient. Data were analyzed using two-sided rank tests. Medians, means, and standard deviations are provided for all measurements. RESULTS: Accommodative amplitude was measured monocularly using a near-point "push" technique from both a 70-cm and 30-cm starting point. An increase in accommodative amplitude of surgical eyes by +1.7 +/- 1.5 diopters and +1.5 +/- 1.2 diopters, at these two testing distances, respectively, was noted at 6 months postoperatively (P <.0001). A smaller increase was also seen in control eyes (+1.2 +/- 1.1 diopters and +1.3 +/- 1.2 diopters, respectively). There was notable intercenter variation in gains in accommodation, with three of seven centers showing significant improvement in near-point accommodative amplitudes relative to the others (P =.0003). There was a median improvement of uncorrected near acuity in surgical eyes by 0.3 logarithm of the minimal angle of resolution (logMAR) at 30 and 40 cm and by 4 lines at 20 cm, with the difference in near acuity improvement at 6 months between SEB eyes and control eyes statistically significant at 20 cm (P <.030). Changes in spherical equivalence, axial length, and central keratometry readings were not statistically significant. There were no reports of anterior segment ischemia or malignant glaucoma. Adverse effects were limited to a transient elevation of intraocular pressure in one patient and misalignment of individual SEB segments, due to inadequate scleral pocket formation, in three patients. Only one SEB segment in one eye was replaced. It appears that the thickness and uniformity of the scleral belt loop is critical to the proper positioning and efficacy of the SEB segments. CONCLUSION: While the safety profile of SEB segments for the treatment of presbyopia was high, a modest improvement in near vision was noted in approximately half the patients using subjective methods of testing. The mechanisms that underlie improvement in near vision in the nonoperated eye await explanation. This may be due to a centrally controlled consensual response, potentiated convergence generating increased intravitreal pressure and hydraulic lift of the vitreo-zonular-lens diaphragm, or artifact from current testing techniques. Future studies of the SEB procedure should address the issue of intercenter variation by further standardizing and automating specific aspects of the surgical technique, as well as incorporating objective testing methods into the study design.     

Scleral buckling technique for longstanding inferior rhegmatogenous retinal detachments with subretinal bands.

We investigated the effectiveness and safety of conventional surgery on longstanding retinal detachments (RD) with subretinal bands (SRB). We found that conventional surgery were safe and effective method in the treatment of inferior chronic rhegmatogenous RD cases with SRB without other signs of advanced proliferative vitreopathy. Further studies with larger numbers and longer follow up are needed.     

Potential effect on the retinoscopic reflex of scleral expansion surgery for presbyopia.

PURPOSE: In this initial study, we model the impact of crystalline lens movement and tilt, which we postulate are a potential consequence of scleral expansion surgery (SES). We demonstrate the possibility that these lead to an improvement in near vision with no concurrent restoration of lens accommodative function. With the implantation of scleral expansion bands (SEB), Schachar predicts an increase in the amplitude of accommodation not observed objectively. We postulate that the SEB implants cause the crystalline lens to be shifted forward and become misaligned. Using mathematical models of the optics of the human eye, we assess the effects of our postulate on the power of the eye, the depth of field, optical aberrations, and the appearance of the horizontal retinoscopic reflex. METHODS: Using anatomically based models of the human eye, the postulated effects of SES are theoretically modeled and optically analyzed in Code V for unintentional lens anterior movement, tilts, and decentrations of up to 1 mm, +/- 3 degrees , and +/- 0.3mm, respectively. The transverse aberrations are calculated before and after SES. Because it has been reported that the appearance of the retinoscopic reflex is consistent with the presence of excess aberrations, we also predict the appearance of the one-dimensional retinoscopic reflex for our models. The change in refractive error is also determined. RESULTS.: Unintentional lens shift, tilt, and decentration, as might occur as a result of SES surgery, would result in an increase in the total power of the eye along with an increase in asymmetric aberrations and little change in symmetric aberrations. The calculated appearances of the retinoscopic reflexes pre- and postsurgery are consistent with observations in the literature. CONCLUSIONS: Scleral expansion surgery could produce an improvement in near vision through an unintentional anterior displacement of the crystalline lens in combination with excess tilts and decentrations rather than as a result of a restoration of lens accommodation. There is a need for measurements and further analysis of the optical and visual properties of SES patients postsurgery.     

Scleral expansion band procedure: Therapy for ocular hypertension and primary open-angle glaucoma

The scleral expansion band procedure (SRP) reverses presbyopia and increses the baseline tension of the ciliary muscle, which increases the trabecular meshwork pore size. By increasing the pore size, SRP is a new therapeutic and preventive modality for ocular hypertension and primary open-angle glaucoma.     

Theoretical basis for the scleral expansion band procedure for surgical reversal of presbyopia (SRP)

A new technique, the scleral expansion band procedure, has been developed for the surgical reversal of presbyopia. The effects of scleral expansion band are based on a recently developed theory by Schachar, which states that the crystalline lens is under increased equatorial zonular tension during accommodation. An understanding of demonstrable clinical effects of the scleral expansion band procedure, based on Schachar's theory, requires a revision of historically held views concerning the mechanism of accommodation.     

Compensation for presbyopia using contact lenses

Contact lens fitting for presbyotic patients needs more than simple fitting shill; patients need additional psychological support. The wearer has to accept optical quality reduction due to the multifocality of the lens design. In general, the technical fitting of presbyotic contact lenses is comparable to monofocal systems. They work with the same rules of performance. The difference lies in the principles of correction by the lens itself. Simple presbyotic systems use uncorrected optical aberration to widen depth perception. These lenses are suitable for young presbyopes, up to a need of 1 diopter plus power for near vision. Uncorrected aspherical designs have a multifocal effect which can be used for presbyotic lenses. There are contact lenses on the market with simultaneous imaging, which is based on concentric rings around the near or distance centre. Another principles are based on segmented reading portions in the lower part of the lens, also called alternating systems. These very few design variations are the basis for the various specific models which are sold on the market today. The results of the fitting can never be foreseen as subjective and psychological aspects of the wearer overlay the objective results. Thus, the fitter needs experience and patient understanding, combined with fundamental knowledge of the specific lens type used.     

老视手术治疗进展

随着人们对视觉质量要求的提高,不损伤远视力的前提下恢复近视力是目前老视矫正手术所追求的目标.为了达到此目的,出现了多种手术方法.本文就近年来国内外报道的有关角膜、晶状体及巩膜等的老视矫正术作一综述.     

Scleral outfolding for macular translocation

PURPOSE: To report experimental study and clinical observation of scleral outfolding for macular translocation.METHODS: In six human cadaver eyes, circumferential mattress sutures to create sclera infoldings were compared with radial-interrupted mattress sutures to create scleral outfoldings. In a 75-year-old man with macular degeneration and choroidal neovascular membrane, radial-interrupted mattress sutures were used for macular translocation.RESULTS: In the human cadaver eyes, circumferential mattress sutures for scleral infolding created an average decrease in corresponding internal anteroposterior retinal contour of 0.36 mm. Radial-interrupted mattress sutures for scleral outfoldings created an average decrease in the corresponding internal anteroposterior retinal contour of 4. 61 mm. The statistical significance of the difference between infoldings of the sclera versus outfoldings of the sclera had a P value of.0001. CONCLUSIONS: Initial experimental and clinical study suggests that radial-interrupted mattress sutures may generate more shortening of the internal scleral surface and greater macular translocation than circumferential mattress sutures. Additional studies are needed to evaluate the long-term effects of radial-interrupted mattress sutures and macular translocation for treatment of subfoveal choroidal neovascularization secondary to age-related macular degeneration.