Techniques that use anterior transposition of scleral flaps change physiological dynamics (8, 11, 12). Anterior transposition tightens the rectus muscles and works as resection on agonist and antagonist muscles simultaneously, and these muscles begin to counteract each other. Therefore, excursions in the muscle direction will be restricted (13). Additionally, the anterior forward of especially vertical extraocular muscles affect the check ligaments and may result in ptosis (14). Furthermore, forward displacement of flaps loosens oblique muscles and disables them. To the best of the author’s knowledge, there are no reports on the continuation of working oblique muscle motility in an eviscerated eye in the literature yet. Additionally, due to the disturbance of orbital anatomy, the maintenance of convergence and divergence has not been mentioned in any report. The essence of this technique is filling the orbita close to the anatomical position. The extraocular muscles resume action in the nearest physiological position, so the implant acquires motility in all excursions as the capacity of the extraocular muscle allows. The oblique muscles and convergence and divergence reflex resume action in addition to vertical and horizontal excursions. To date, this technique is the only reported technique that gives the socket this degree of mobility.
Although the main opinion about this technique is based on the letter of Kamal and Kumar, it requires several revisions (10). Kamal and Kumar mentioned in their letter the construction of four rectangular scleral flaps, each approximately 6 × 12 mm in size. This provided a useful guide for inserting the implant close to the anatomical position. However, solely relying on this knowledge does not ensure the stability of the sphere in its place. The development of a decent evisceration technique that is resilient to implant exposure and enhances implant motility by maintaining the implant close to the anatomical position requires much more experience and revision than what Kamal and Kumar's work provides. Nevertheless, the author acknowledges their help. The surgeon did not know how a sphere could pass through a narrow limbal area, and four rectangular scleral flaps could not cover the anterior side of the sphere completely. To develop a feasible technique, the surgeon made several modifications. For an appropriate implant size, relaxing incisions should be made radially in four regions from the insertion of each of the four recti muscles up to the apex of the cornea to expand the scleral shell in front of the equator. While preserving corneal tissue is a revision, this alone is not enough. Making it resistant to exposure requires additional adjustments. Debriding the corneal epithelium facilitates conjunctivalization when covered by the conjunctiva. Additionally, forward displacement of the conjunctiva requires graft insertion. Implementing these changes demands experience, and they differ from what Kamal and Kumar teach. Therefore, the author attributed this technique to the surgeon and named it the caging technique.
Although there are no reports in the literature on the most effective technique against implant exposure, the general bias is that the techniques that use the scleral petals anteriorly to cover the implant are the most effective (12, 15). Massry & Holds and Sales-Sanz & Sanz-Lopez used this method (4, 5). Although they reported no cases of implant exposure, Masdottir & Sahlin and Smith reported implant exposure rates of 5% and 1.49%, respectively, in their large series (16, 17). The patients in this series were selected from those who had not developed implant exposure based on the defined criteria. This means that if evisceration surgery is performed according to these defined criteria, implant exposure will never develop. Therefore, it can be argued that this technique is as effective as previous techniques against implant exposure.
The main limitations of this study are its retrospective nature, absence of a control group with any other technique, small sample size, single-center nature, and potential selection bias. Addressing these limitations through a prospective, controlled study with a larger sample size is beyond the ability of any single surgeon. Multicenter collaboration is needed.
The main strength of this study is its presentation of a novel surgical technique aimed at enhancing implant motility in eviscerated eyes. This technique appears to address a significant gap in existing evisceration techniques by providing enhanced implant motility comparable to that of the fellow eye in all excursions. Additionally, the study demonstrated the efficacy of the technique through a detailed description of the surgical procedure, retrospective analysis of patient outcomes, and documentation of implant motility in various gaze directions. Furthermore, the study offers insights into the evolution of the technique through revisions and improvements made over time, demonstrating a commitment to refining surgical approaches based on clinical experience and outcomes. The inclusion of video recordings and figures enhances the understanding of the surgical technique and patient outcomes, adding depth to the presentation of results. This technique enables the implant to be in the place where previously intraocular tissue resides and provides a promising option for patients seeking improved implant motility and cosmesis.
In conclusion, this technique allows the placement of a sphere close to the anatomical position and avoids disturbing any extraocular muscle insertion, direction, or strength. The check ligaments and suspensory ligaments remain uncompromised. In the Tillaux spiral, the pulleys are preserved despite the insertion of a sphere. This is closely associated with physiological three-dimensional Tenon’s capsule-pulley reconstruction. These pulleys are dependent upon the intermuscular septum and Tenon's fascia for their support and are believed to be the functional origin of the muscles (18, 19). Once the sphere becomes a fulcrum for the tenon, suspensory ligaments, and extraocular muscles, the implant gains maximum extraocular movement, including oblique muscles. Implant motility can reach levels approximately similar to those of fellow eyes in patients in all versions without incomitance.