Existing evidence suggests DMEK is safe, effective for endothelial failure

This assessment by the Ophthalmic Technology Assessment Committee of the Academy’s Cornea and Anterior Segment Disorders Panel reviews the safety and outcomes of Descemet membrane endothelial keratoplasty (DMEK) to treat corneal endothelial dysfunction.

Study design

The authors reviewed the abstracts of 1,085 articles from the PubMed and Cochrane Library Literature databases, and selected 47 large (>25 DMEK cases), prospective, controlled clinical studies; and observational studies for inclusion in the final assessment. Of the 47 studies, the panel’s methodologist rated 2 as level I evidence, 15 as level II evidence and 30 as level III evidence.

Key search terms included Descemet membrane endothelial keratoplasty, Descemet’s membrane endothelial keratoplasty, DMEK, posterior lamellar keratoplasty and endothelial keratoplasty. Studies of nonhuman and deep anterior lamellar keratoplasty were excluded.

Outcomes

By 6 months after DMEK surgery, up to 85% of eyes achieved a BCVA of 20/25 or better and up to 67% achieved a BCVA of 20/20 or better. Each study showed a rapid visual recovery after successful DMEK, with final mean BCVA ranging from 20/21 to 20/31.

The most common complication was partial graft detachment requiring air injection (mean 29%), followed by elevated IOP (range 0-22%), primary graft failure (mean 1.7%), secondary graft failure (mean 2.2%) and immune rejection (mean 1.9%).

The 7 studies that directly compared the visual outcomes of DMEK and Descemet’s stripping endothelial keratoplasty (DSEK) all showed better visual outcomes after DMEK (6 of these 7 studies were rated as level II evidence). Recovery times, complication and rejection rates also favored DMEK.

Limitations

The searches were limited to English-language abstracts, potentially excluding key findings published in other languages.

Clinical significance

Evidence from the published literature supports DMEK as a safe and effective treatment for endothelial failure. Regarding recovery time, visual outcomes, and complication and rejection rates, DMEK seems to be superior to DSEK.

https://www.aao.org/editors-choice/existing-evidence-suggests-dmek-is-safe-effective-

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Most wet AMD patients can safely stop anti-VEGF treatment after a treat-and-extend protocol

This retrospective review examined recurrence of choroidal neovascularization (CNV) in patients who were weaned off a treat-and-extend anti-VEGF regimen for wet AMD.

Study design

The cohort comprised 385 eyes (321 patients) who were treated with anti-VEGF injections at 4-week intervals. If the macula remained “dry”, treatment was extended by 1- to 2-week intervals until the injections were 12 weeks apart. Treatment was stopped if there were no signs of disease activity, and reinitiated if there was new or recurrent CNV.

Outcomes

Approximately 37% of eyes (143 eyes of 120 patients) met criteria for treatment cessation over the average follow-up of 27 months. The overall recurrence rate was 29% (42 eyes of 36 patients) at a median of 14 months after stopping therapy.

Mean BCVA was 20/50 at the time of therapy cessation and 20/60 at the time of recurrence. However, most patients recovered their baseline vision after treatment was reinitiated.

Limitations

This is a retrospective study. While the majority of patients recovered vision, 6 out of 42 eyes lost more than 3 lines of vision. While 2 of those eyes achieved significant improvements in vision after restarting therapy, 4 eyes (3% of the total cohort) experienced significant and permanent vision loss.

Clinical significance

This study answers an important question for retina specialists: Are patients safely able to stop treatment if they are using a treat-and-extend protocol? The majority of patients still need to receive ongoing treatment as their disease remains active. However, in this series approximately 1/3 of patients were able to stop therapy for approximately 1 year.

With close and regular follow up, recurrence of disease can be managed successfully. However, patients should be counseled that some people may lose vision that may not be fully recoverable. Whether this outcome is unique to this protocol, or is part of the natural history of the disease has yet to be determined.

https://www.aao.org/editors-choice/most-wet-amd-patients-can-safely-stop-anti-vegf-tr

Predicting postoperative refraction: Which formula is best?

This retrospective case series compared the accuracy of 7 popular IOL formulas for predicting postoperative refraction in eyes of all ocular dimensions

Study design

The analysis included 18,501 eyes receiving an Alcon monofocal IOL (SN60WF or SA60AT IOL) over an 18-month period. All eyes had biometry with the Lenstar 900 optical biometer.

Investigators analyzed the error in predicted spherical equivalent of each formula (Barrett Universal II, Haigis, Hoffer Q, Holladay 1, Holladay 2, Olsen, and SRK/T), including the Wang-Koch adjustment (Holladay 1, Hoffer Q, Haigis, SRK/T) for eyes with axial length longer than 25 mm.

Outcomes

For the SN60WF, the Barrett Universal II had the significantly lowest mean absolute error followed by the Olsen, Haigis 1, Holladay 1 Wang-Koch, Holladay 2, Holladay 1, Hoffer Q Wang-Koch, SRK/T, SRK/T Wang-Koch, Hoffer Q, and Haigis Wang-Koch. The results were similar for the SA60AT IOL.

For long eyes (>25.5mm), Olsen had the lowest mean error followed by Barrett, whereas Haigis Wang-Koch, Hoffer Q, and Holladay 1 were worst. For short eyes (<22.5mm), Barrett and Holladay 1 Wang-Koch were most accurate, and Hoffer Q, Holladay 2 and Hoffer Q Wang-Koch were least accurate.

Of note, all 7 formulas without the WK adjustment give results that within 0.1 D of predicted spherical equivalent for eyes with axial lengths between 23 and 25 mm. The major reason for the difference between the formulas is their performance outside this range.

Limitations

These results may not apply to other IOL models and manufacturers. Due to a retrospectively optimized Haigis a0 constant and a large number of surgeons in the study (127 for SN60WF and 95 for SA60AT), the results may not hold true for individual surgeons. A significant number of patients (6,476) were excluded due to missing postoperative refractive information in the 2-week to 4-month postoperative period, possibly skewing results.

Clinical significance

Findings from this large study suggest the Barrett Universal II is the best overall formula, and had a high accuracy for both short and long eyes. The Hoffer Q was least accurate for short eyes. In general, applying the Wang-Koch modification of axial length for long eyes resulted in a shift from hyperopic to myopic outcomes.

https://www.aao.org/editors-choice/predicting-postoperative-refraction-which-formula-

Vector vs. manifest refraction planning yield similar LASIK outcomes


FEB 26, 2018

Refractive Mgmt/Intervention

This retrospective study compared vector planning to manifest refraction planning in patients undergoing LASIK for myopic astigmatism.

Study design

The study included 85 treatments based on manifest astigmatism and 79 treatments based on vector planning, which incorporates both manifest refraction and corneal topographic shape. All patients received LASIK with an aberration-neutral profile centered on the visual axis considering 70% of the pupil offset toward the corneal vortex. The treatments used were based 60% emphasis on refractive astigmatism and 40% emphasis on corneal astigmatism.

Only patients with a preoperative ocular residual astigmatism (ORA) of greater than 0.75 D were included. The ORA is defined by the vector difference between the manifest and corneal astigmatism.

Outcomes

Overall, there were no significant differences in postoperative refractive astigmatism, corrected distance visual acuity or uncorrected distance visual acuity between the groups.

The 6-month postoperative mean spherical equivalent favored the vector group, although the minimum level of detection versus the absolute differences in the mean suggested inadequate sample size to confirm these findings. Postoperative ORA and corneal toricity also favored the vector group.

There were no differences in target-induced astigmatism and achieved surgically induced astigmatism, correction index or HOAs (higher order aberrations).

Limitations

Patients were required to have normal keratometry reading and topography, so this may have limited applicability to cases with the highest ORA.

Clinical significance

Performing LASIK for myopic astigmatism with the vector planning approach yielded comparable visual outcomes as manifest refraction planning.

https://www.aao.org/editors-choice/subtle-differences-between-vector-vs-manifest-refr

Blood Vessel Support and Prevention Package for Macular Degeneration Support

amd-4g2-email.gifA major problem with advanced Macular Degeneration is the growth of blood vessels in the eye. These unwanted blood vessels develop in the late stages of Age-Related Macular Degeneration (ARMD), also known as “wet” ARMD. Dr. Marc Grossman at Natural Eye Care has developed a package of supplements aimed at strengthening the retina and reducing the risk of new blood vessel growth.

New blood vessels obscure vision. Wet ARMD patients have few options. Doctors can sometimes zap the eye with lasers in an attempt to reduce the rate of future blood vessel growth. Oral drugs such as ranibizumab can help stop new blood vessels from developing. Injectable drugs are also aimed at stopping the extra blood vessel growth. All these options carry potential side effects and damage.

In consultation with their eye doctors, some wet AMD patients have tried research-based targeted nutrition. Certain vitamins, nutrients, homeopathics, and Traditional Chinese Medicine remedies are aimed at supporting the eyes. The AMD Package 4G2 contains nutrients to help strengthen the retina, and blood vessels, and reduce the risk of new unwanted blood vessel growth.

Contents of the ARMD Package

Advanced Eye and Vision Support Formula provides antioxidants for both eyes and total body health. Eye-specific nutrients include lutein, bilberry, special Chinese herbs, carrot root, and more.

Krill Oil Complex is an important source of omega-3 fatty acids.  Additionally, krill provides a treasured antioxidant for heart and vision health called “astaxanthin.” (LINK)

Vitamin D3 is for retinal and overall body support. Research has indicated this vitamin could reduce ARMD risk.1 Many Americans have low vitamin D due to indoor activities and less sunlight exposure in the winter. Vitamin D supports immunity, skeletal health, the heart, and cognition.

Dr. Grossman’s Blood Vessel Formula is designed to help prevent the growth of unwanted blood vessels. This wild-crafted herbal formula is based on a National Institutes of Health study.2 Includes ginkgo biloba, grape extract, cinnamon, ginseng and more. Click for ingredients.

See the AMD Package 4G2 in the Natural Eye Care Store.

https://www.naturaleyecare.com/blog/blood-vessel-growth-prevention-package-macular-degeneration/

Surgical management strategies for trachomatous trichiasis

This Current Insight outlines current evidence supporting surgical management strategies for trachomatous trichiasis.

PLTR and BLTR: Two tried and tested techniques

Published in the August 2017 issue of Ophthalmology, the study Predictors of Trachomatous Trichiasis Surgery Outcome compares 2 tarsal rotation surgeries: posterior lamellar tarsal rotation (PLTR) and bilamellar tarsal rotation (BLTR).

Clinical trials have shown that PLTR and BLTR are more effective than alternative surgical procedures for the management of trachomatous trichiasis (TT) in trachoma-endemic settings. These tarsal rotation procedures are therefore recommended by the World Health Organization (WHO). 

In particular, two trials examined the relative effectiveness of BLTR, tarsal advance and rotation, eversion splinting, tarsal advance (lid split), tarsal advance and grafting, and tarsal grooving. Both trials found the BLTR procedure to be superior than other strategies for the management of TT.1,2 Furthermore, BLTR can be readily taught to non-ophthalmologists, and can be easily and safely performed in rural health facilities. These are key advantages because, worldwide, most TT surgeries are delivered by non-physician health workers.

ALR: An unknown entity

To date, no randomized controlled trials have compared the anterior lamellar recession/repositioning (ALR) with either BLTR or PLTR for trachomatous trichiasis. One retrospective case series compared outcomes of BLTR and ALR procedures performed at different times. The study found a 46% risk of recurrance for BLTR and 17% risk for ALR, but these did not reach statistical significance.3 However, that study was limited by inconsistent follow-up times, a lack of surgeon standardization and an inadequate sample size, which make it difficult to draw meaningful conclusions.

A prospective noncomparative study conducted in Egypt reported a 34% recurrence rate at 6 months after ALR.4 A prospective non-comparative series from Iran of 32 cases with upper lid cicatricial entropion found a 25% recurrance rate at 1 year for ALR combined with blepharoplasty (excision of excess anterior lamella) and supratarsal fixation.5 These recurrence rates are higher than those reported in a recent trial comparing PLTR and BLTR (13% and 22%, respectively, at 1 year).6

In the aforementioned studies of ALR for TT, surgery was conducted by highly experienced surgeons; recurrence rates may be higher when performed by non-physician cadres with relatively limited training.7,8  Previous studies have consistently found that surgeon technique/ability is a crucial determinant of success.

Drawbacks of ALR

Critics have noted that ALR may not be sufficient for some phenotypes of TT because it does not address the posterior lamella. Therefore, it may prove ineffective in cases with severe posterior lamellar scarring and shortening, or cases with metaplastic lashes emanating from the posterior lamella, which occur commonly in trachoma.6,9-12 Because of this concern, ALR is usually reserved for cases with mild-to-moderate entropic trichiasis without metaplastic lashes emanating from the posterior lamella.

The literature generally advises that ALR be modified and combined with other more complicated techniques for various phenotypes of trachomatous trichiasis.9 For instance, in cases of thickened tarsus, which is usually the case in TT patients, ALR should be combined with a tarsal wedge resection. For cases with lid retraction secondary to the scarred, shortened posterior lamella, ALR should be combined with dissection of the levator aponeurosis and Muller’s muscle, followed by advancing the tarso-conjunctiva.9 This individualized and tailored surgical approach may be suitable for highly skilled oculoplastic surgeons, but is not a practical strategy for nurses who manage a high volume of cases in trachoma-endemic settings. It would be difficult to tailor surgical procedures to the various stages of disease, given the current TT backlog that must be rapidly addressed to prevent ongoing incident visual impairment. Fortunately, the Ophthalmology paper and other studies of BLTR and PLTR have shown that these procedures are overall quite effective ‘one size fits all’ approaches that can be safely and effectively performed by trained non-physicians.  

While some physicians suggest refraining from making an incision in the posterior lamella, there is no evidence to support this stance. By contrast, there is strong evidence to indicate that surgical procedures involving the posterior lamella should be employe for severe cases of TT with metaplastic lashes and major lid shortening. Specifically, tarso-conjunctival rotation procedures, such as the PLTR, can provide adequate 180° rotation of the lid margin.9,13-15

Which surgery type is best?

A recent trial result comparing PLTR with BLTR shows that PLTR is more effective against the full spectrum of TT cases, with a lower rate of postoperative trichiasis among cases of varying severity. The findings suggest that PLTR is preferable for use in the programmatic management of varied phenotypes of TT, and where surgeries are performed by non-physician cadres with limited training.6 It is worth noting that TT recurrence, when encountered, is almost always minor (less than five lashes). This dramatically reduces the risk of corneal scarring and blindness from  trichiasis.  

In summary, the current literature indicates that tarsal rotation surgeries are superior to other approaches for the programmatic management of TT in trachoma-endemic settings. ALR has not been formally compared with tarsal rotation procedures, but is unlikely to be superior as it does not address the often-significant entropion caused by posterior lamella scarring.  

References

  1. Reacher M, Huber M, Canagaratnam R, Alghassany A. A trial of surgery for trichiasis of the upper lid from trachoma. British Journal of Ophthalmology 1990; 74(2): 109-13.
  2. Reacher M, Muñoz B, Alghassany A, et al. A controlled trial of surgery for trachomatous trichiasis of the upper lid. Archives of Ophthalmology 1992; 110(5): 667-74.
  3. Barr K, Essex RW, Liu S, Henderson T. Comparison of trichiasis recurrence after primary bilamellar tarsal rotation or anterior lamellar repositioning surgery performed for trachoma. Clinical and Experimental Ophthalmology 2014; 42(4): 311-6.
  4. Ahmed RA, Abdelbaky SH. Short Term Outcome of Anterior Lamellar Reposition in Treating Trachomatous Trichiasis. Journal of Ophthalmology 2015; 2015: 568363.
  5. Aghai GH, Gordiz A, Falavarjani KG, Kashkouli MB. Anterior lamellar recession, blepharoplasty, and supratarsal fixation for cicatricial upper eyelid entropion without lagophthalmos. Eye 2016; 30(4): 627-31.
  6. Habtamu E, Wondie T, Aweke S, et al. Posterior lamellar versus bilamellar tarsal rotation surgery for trachomatous trichiasis in Ethiopia: a randomised controlled trial. The Lancet Global Health 2016; 4(3): e175-e84.
  7. Rajak SN, Collin JR, Burton MJ. Trachomatous trichiasis and its management in endemic countries. Survey of ophthalmology 2012; 57(2): 105-35.
  8. Burton MJ, Habtamu E, Ho D, Gower EW. Interventions for trachoma trichiasis. Cochrane Database of Systematic Reviews 2015; (11): CD004008.
  9. Kemp EG, Collin JR. Surgical management of upper lid entropion. The British journal of ophthalmology 1986; 70(8): 575-9.
  10. Rajak SN, Habtamu E, Weiss HA, et al. The Clinical Phenotype of Trachomatous Trichiasis in Ethiopia: Not All Trichiasis Is Due to Entropion. Investigative Ophthalmology & Visual Science 2011; 52(11): 7974-80.
  11. Rajak SN, Habtamu E, Weiss HA, et al. Absorbable versus silk sutures for surgical treatment of trachomatous trichiasis in Ethiopia: a randomised controlled trial. PLoS medicine 2011; 8(12): e1001137.
  12. Rajak SN, Habtamu E, Weiss HA, et al. Surgery Versus Epilation for the Treatment of Minor Trichiasis in Ethiopia: A Randomised Controlled Noninferiority Trial. PLoS Med 2011; 8(12): e1001136.
  13. Waddell K. A new clamp for bilamellar tarsal rotation for trachomatous trichiasis. Community Eye Health 2009; 22(69): 13.
  14. Kettesy A. ON GENESIS AND OPERATION OF THE CICATRICIAL (TRACHOMATOUS) ENTROPION OF THE UPPER LID. The British journal of ophthalmology 1948; 32(7): 419-23.
  15. Nasr AM. Eyelid complications in trachoma. I. Cicatricial entropion. Ophthalmic surgery 1989; 20(11): 800-7.

https://www.aao.org/current-insight/surgical-management-strategies-trachomatous-trichi

Noninferiority trials confirm IOP benefits of once-daily latanoprostene bunod


FEB 06, 2018

Glaucoma

This pooled analysis assessed the efficacy and safety of latanoprostene bunod compared with timolol for the treatment of open-angle glaucoma.

Study design

The authors analyzed data from two phase 3, randomized, multicenter, double-masked, parallel-group, noninferiority trials (APOLLO and LUNAR), comprising 840 participants. Adults with open-angle glaucoma or ocular hypertension were randomized 2:1 to receive once-daily latanoprostene bunod (0.024%) or twice-daily timolol (0.5%) for 3 months.

Outcomes

Patients on latanoprostene bunod achieved a significantly lower mean IOP compared with timolol patients at 9 evaluation time points throughout 3 months of follow-up. The latanoprostene arm also had a greater number of subjects that attained a mean IOP of ≤18 mm Hg and an IOP reduction of ≥25% from baseline.

The study detected a 5.9% rate of conjunctival hyperemia in the latanoprostene bunod group. Eye irritation and pain occurred in less than 5% of patients. There were no serious safety concerns.

Limitations

The results might have been more clinically applicable if latanoprostene bunod had been compared with a prostaglandin analogue rather than timolol.

Clinical significance

This robust study confirms the efficacy of this novel ocular hypotensive agent, which was approved by the FDA in November 2017. Prior studies suggest that the agent may be more efficacious than prostaglandin analogues, which are currently considered first-line therapies. Further head-to-head trials comparing latanoprostene bunod with a prostaglandin therapy would help to elucidate which drug should be used as a first-line treatment.

https://www.aao.org/editors-choice/noninferiority-trials-confirm-iop-benefits-of-once