Outcomes and Complications of Limbal Stem Cell Allograft Transplantation: A Report by the American Academy of Ophthalmology

PURPOSE

To review the published literature on the safety and outcomes of keratolimbal allograft (KLAL) transplantation and living-related conjunctival limbal allograft (lr-CLAL) transplantation for bilateral severe/total limbal stem cell deficiency (LSCD).

METHODS

Literature searches were last conducted in the PubMed database in February 2023 and were limited to the English language. They yielded 523 citations; 76 were reviewed in full text, and 21 met the inclusion criteria. Two studies were rated level II, and the remaining 19 studies were rated level III. There were no level I studies.

RESULTS

After KLAL surgery, best-corrected visual acuity (BCVA) improved in 42% to 92% of eyes at final follow-up (range, 12-95 months). The BCVA was unchanged in 17% to 39% of eyes and decreased in 8% to 29% of eyes. Two of 14 studies that evaluated the results of KLAL reported a notable decline in visual acuity over time postoperatively. Survival of KLAL was variable, ranging from 21% to 90% at last follow-up (range, 12-95 months) and decreased over time. For patients undergoing lr-CLAL surgery, BCVA improved in 31% to 100% of eyes at final follow-up (range, 16-49 months). Of the 9 studies evaluating lr-CLAL, 4 reported BCVA unchanged in 30% to 39% of patients, and 3 reported a decline in BCVA in 8% to 10% of patients. The survival rate of lr-CLAL ranged from 50% to 100% at final follow-up (range, 16-49 months). The most common complications were postoperative elevation of intraocular pressure, persistent epithelial defects, and acute allograft immune rejections.

CONCLUSIONS

Given limited options for patients with bilateral LSCD, both KLAL and lr-CLAL are viable choices that may provide improvement of vision and ocular surface findings. The studies trend toward a lower rejection rate and graft failure with lr-CLAL. However, the level and duration of immunosuppression vary widely between the studies and may impact allograft rejections and long-term graft survival. Complications related to immunosuppression are minimal. Repeat surgery may be needed to maintain a viable ocular surface. Reasonable long-term success can be achieved with both KLAL and lr-CLAL with appropriate systemic immunosuppression.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Advanced Corneal Imaging in Keratoconus: A Report by the American Academy of Ophthalmology

PURPOSE

To review the published literature on the diagnostic capabilities of the newest generation of corneal imaging devices for the identification of keratoconus.

METHODS

Corneal imaging devices studied included tomographic platforms (Scheimpflug photography, OCT) and functional biomechanical devices (imaging an air impulse on the cornea). A literature search in the PubMed database for English language studies was last conducted in February 2023. The search yielded 469 citations, which were reviewed in abstract form. Of these, 147 were relevant to the assessment objectives and underwent full-text review. Forty-five articles met the criteria for inclusion and were assigned a level of evidence rating by the panel methodologist. Twenty-six articles were rated level II, and 19 articles were rated level III. There were no level I evidence studies of corneal imaging for the diagnosis of keratoconus found in the literature. To provide a common cross-study outcome measure, diagnostic sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were extracted. (A perfect diagnostic test that identifies all cases properly has an AUC of 1.0.) RESULTS: For the detection of keratoconus, sensitivities for all devices and parameters (e.g., anterior or posterior corneal curvature, corneal thickness) ranged from 65% to 100%. The majority of studies and parameters had sensitivities greater than 90%. The AUCs ranged from 0.82 to 1.00, with the majority greater than 0.90. Combined indices that integrated multiple parameters had an AUC in the mid-0.90 range. Keratoconus suspect detection performance was lower with AUCs ranging from 0.66 to 0.99, but most devices and parameters had sensitivities less than 90%.

CONCLUSIONS

Modern corneal imaging devices provide improved characterization of the cornea and are accurate in detecting keratoconus with high AUCs ranging from 0.82 to 1.00. The detection of keratoconus suspects is less accurate with AUCs ranging from 0.66 to 0.99. Parameters based on single anatomic locations had a wide range of AUCs. Studies with combined indices using more data and parameters consistently reported high AUCs.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Examination of a Modified Graft Preparation Technique to Induce Double-Scroll Formation and Promote the Use of Younger Descemet Membrane Endothelial Keratoplasty Donor Tissue

PURPOSE

The purpose of this study was to determine whether controlled balanced salt solution (BSS) bursts during graft preparation can safely promote formation of a double-scrolled Descemet membrane endothelial keratoplasty (DMEK) graft in younger donor tissue.

METHODS

DMEK grafts prepared from young donor tissue (average age, 55 years; range, 39-66 years) were floated in BSS to spontaneously form scrolls (N = 10 pairs). Controlled BSS bursts were used to promote double-scroll (DS) formation in 1 member of each pair. Grafts were stained, preloaded, and shipped before cell viability analysis. After appropriate training, a less experienced technician performed this technique on 10 additional corneas. Outcomes measured for both technicians include the success rate for obtaining a DS, scroll conformation after shipping, and endothelial cell loss (ECL).

RESULTS

There was no difference in ECL between grafts subjected to additional manipulation compared with unmanipulated mate grafts (observer 1: 15.2% ± 3.3% vs. 15.2% ± 4.4%, P = 0.99; observer 2: 16.3% ± 2.9% vs. 15.9% ± 4.5%, P = 0.8). A technician experienced with this technique had a 90% success rate, whereas a less experienced technician had a 70% success rate. The mean ECL of the 10 grafts manipulated by the less experienced technician was not significantly different from results obtained from the experienced technician (observer 1: 18.5% ± 6.0% vs. 15.2% ± 3.3%, P = 0.15; observer 2: 18.1% ± 5.6% vs. 16.3% ± 2.9%, P = 0.34). Scrolls maintained their conformation during shipping events.

CONCLUSIONS

Double-scroll graft formation using controlled BSS bursts is a reliable technique that can be performed without causing additional damage to DMEK grafts. This technique may make graft unscrolling easier and can promote the use of younger donor tissue for DMEK.

Management of endothelial disease without keratoplasty

PURPOSE OF REVIEW

Currently, the most widely used treatment for endothelial disease is endothelial replacement via endothelial keratoplasty. Increasingly selective techniques have allowed for increased safety and faster visual recovery. However, alternative treatment options that are lower in cost, require less surgical expertise, and rely less on tissue availability are needed. This review discusses established and emerging therapies for endothelial disease without keratoplasty.

RECENT FINDINGS

Regenerative therapies that have been successful include Descemet stripping only and Descemet membrane transplants. Rho-kinase inhibitors promote cell proliferation, adhesion, and migration and appear to have a role in these treatments and possibly in the prevention of endothelial disease. Cell-based therapies and the development of an artificial endothelial implant have also demonstrated promising results.

SUMMARY

There are numerous emerging treatments for endothelial disease that have proven successful. Advances in our understanding of disease pathogenesis on a cellular level will continue to expand possibilities for therapeutics.

Retinal detachment associated with traumatic chorioretinal rupture

Traumatic chorioretinal rupture, also known as sclopetaria, is a full-thickness break of the choroid and retina caused by a high-velocity projectile striking or passing adjacent to, but not penetrating, the globe. Previous reports have emphasized that retinal detachment seldom occurs, and observation alone has been the recommended management strategy. However, the authors present herein a series of consecutive patients with retinal detachment associated with sclopetaria and provide a literature review of the topic. They recommend that patients with traumatic chorioretinal rupture be monitored closely for the development of retinal detachment during the first few weeks after the injury.

Ocular blast injuries in mass-casualty incidents: the marathon bombing in Boston, Massachusetts, and the fertilizer plant explosion in West, Texas

PURPOSE

To report the ocular injuries sustained by survivors of the April 15, 2013, Boston Marathon bombing and the April 17, 2013, fertilizer plant explosion in West, Texas.

DESIGN

Multicenter, cross-sectional, retrospective, comparative case series.

PARTICIPANTS

Seventy-two eyes of 36 patients treated at 12 institutions were included in the study.

METHODS

Ocular and systemic trauma data were collected from medical records.

MAIN OUTCOME MEASURES

Types and severity of ocular and systemic trauma and associations with mechanisms of injury.

RESULTS

In the Boston cohort, 164 of 264 casualties were transported to level 1 trauma centers, and 22 (13.4%) required ophthalmology consultations. In the West cohort, 218 of 263 total casualties were transported to participating centers, of which 14 (6.4%) required ophthalmology consultations. Boston had significantly shorter mean distances to treating facilities (1.6 miles vs. 53.6 miles; P = 0.004). Overall, rigid eye shields were more likely not to have been provided than to have been provided on the scene (P<0.001). Isolated upper body and facial wounds were more common in West largely because of shattered windows (75.0% vs. 13.6%; P = 0.001), resulting in more open-globe injuries (42.9% vs. 4.5%; P = 0.008). Patients in Boston sustained more lower extremity injuries because of the ground-level bomb. Overall, 27.8% of consultations were called from emergency rooms, whereas the rest occurred afterward. Challenges in logistics and communications were identified.

CONCLUSIONS

Ocular injuries are common and potentially blinding in mass-casualty incidents. Systemic and ocular polytrauma is the rule in terrorism, whereas isolated ocular injuries are more common in other calamities. Key lessons learned included educating the public to stay away from windows during disasters, promoting use of rigid eye shields by first responders, the importance of reliable communications, deepening the ophthalmology call algorithm, the significance of visual incapacitation resulting from loss of spectacles, improving the rate of early detection of ocular injuries in emergency departments, and integrating ophthalmology services into trauma teams as well as maintaining a voice in hospital-wide and community-based disaster planning.

Achieving target refraction after cataract surgery

PURPOSE

To evaluate the difference between target and actual refraction after phacoemulsification and intraocular lens implantation at an academic teaching institution's Comprehensive Ophthalmology Service.

DESIGN

Retrospective study.

PARTICIPANTS

We examined 1275 eye surgeries for this study.

METHODS

All consecutive cataract surgeries were included if they were performed by an attending or resident surgeon from January through December 2010. Postoperative refractions were compared with preoperative target refractions. Patients were excluded if they did not have a preoperative target refraction documented or if they did not have a recorded postoperative manifest refraction within 90 days.

MAIN OUTCOME MEASURES

The main outcome measure was percentage of cases achieving a postoperative spherical equivalent ± 1.0 diopter (D) of target spherical equivalent.

RESULTS

We performed 1368 cataract surgeries from January through December of 2010. Of these, 1275 (93%) had sufficient information for analysis. Of the included cases, 94% (1196 of 1275) achieved ± 1.0 D of target refraction by 90 days after cataract surgery.

CONCLUSIONS

This paper establishes a new benchmark for a teaching hospital, where 94% of patients achieved within 1.0 D of target refraction after cataract surgery. The refractive outcomes after cataract surgery at this academic teaching institution were higher than average international benchmarks.