For what living with a graft and a scleral lens involves day to day, see the corneal transplant condition page. This page gathers the numbers and the research.
Transplant numbers in the US
The Eye Bank Association of America (EBAA) publishes an annual statistical report covering its member eye banks. The 2024 report includes 53 US and 12 international eye banks and one accredited US entity, and the EBAA describes it as an essentially complete picture of US eye banking activity.[1]
In 2024, according to the EBAA:[1]
- 71,778 donors gave 141,735 eyes or corneas to US eye banks.
- US eye banks supplied 85,926 corneal grafts in total, for use in the US and abroad.
- 49,427 keratoplasties (full-thickness, front-layer, and back-layer transplants) were performed in the US with that tissue.
Types of transplant
| Procedure (US, 2024) | What’s replaced | Number[1] |
|---|---|---|
| DMEK (Descemet membrane endothelial keratoplasty) | The thin inner layer only | 18,256 |
| DSEK / DSAEK (Descemet stripping endothelial keratoplasty) | The inner layer with a thin layer of supporting tissue | 16,345 |
| PK (penetrating keratoplasty) | The full thickness of the central cornea | 14,143 |
| ALK (anterior lamellar keratoplasty) | The front layers, keeping the patient’s inner layer | 584 |
The two back-layer procedures together (34,700 including smaller variants) are grouped as endothelial keratoplasty (EK). Full-thickness transplants in the US have fallen from a high of 42,063 in 2005 to 14,143 in 2024, a 66.4% decrease. EK overtook full-thickness grafts in 2012 and reached an all-time high in 2024. DMEK overtook DSEK in 2023 and is now the most common transplant procedure in the US.[1]
Why people have transplants
| Reason (US, 2024) | Number | Share of all US grafts[1] |
|---|---|---|
| Endothelial (inner layer) failure, total | 31,124 | 63.0% |
| Fuchs’ and other inherited endothelial dystrophies | 17,391 | 35.2% |
| Secondary endothelial dysfunction | 7,026 | 14.2% |
| Swelling after earlier eye surgery, such as cataract surgery | 6,707 | 13.6% |
| Repeat transplant | 7,586 | 15.3% |
| Stromal or full-thickness disease, total | 5,828 | 11.8% |
| Keratoconus and other ectasias | 1,967 | 4.0% |
| Unknown or not reported | 4,889 | 9.9% |
Keratoconus was the sixth most common specific reason in 2024. It remains the most common single diagnosis for full-thickness transplants, and 91.2% of keratoconus transplants were full-thickness.[1] More figures are on the keratoconus statistics page.
Repeat transplants were 22.8% of full-thickness grafts, 12.4% of endothelial grafts, and 7.2% of front-layer grafts in 2024.[1]
How long grafts last
Graft survival depends heavily on the reason for the transplant, the type of surgery, and the eye. These studies measured different groups, so their numbers shouldn’t be compared directly.
All full-thickness grafts, Australian national registry. In 18,686 full-thickness grafts tracked for up to 22 years, the probability a graft was still working was 0.87 at 1 year, 0.73 at 5 years, 0.60 at 10 years, and 0.46 at 15 years. The most common causes of failure were irreversible rejection (34%), failure of the inner cell layer including cases of glaucoma (24%), and infection (14%). Best-corrected vision of 6/12 (20/40) or better was reached in 45% of grafted eyes.[3]
Full-thickness grafts for endothelial disease, US Cornea Donor Study. In a multicenter trial of 1,090 people, mostly with Fuchs’ dystrophy or swelling after cataract surgery, the 10-year success rate was 77% with donors aged 12 to 65 and 71% with donors aged 66 to 75.[4] Among grafts still working at 5 years, 10-year failure was 12% in eyes with no rejection episode in the first 5 years and 22% in eyes with at least one definite rejection episode.[5]
Full-thickness grafts for keratoconus. These generally do well:
- In a Japanese series of 125 eyes followed for an average of 15.3 years, 93.2% of grafts were still working at 25 years. The authors noted survival gradually declined after 20 years.[6]
- In a New Zealand series of 245 eyes, failure-free survival at 10 years was 92.2% in eyes without prior hydrops. Rejection episodes were more common: 70.9% of those eyes were rejection-free at 10 years.[7]
Scleral lenses instead of a transplant
For some people with keratoconus, a scleral lens can delay or replace surgery.
- At a Belgian university clinic, 40 of 51 eyes with severe keratoconus prescribed scleral lenses instead of transplant surgery were still wearing them after about two and a half years.[9]
- In a single-center US review, scleral lens use was associated with a lower chance of eventually needing a transplant (adjusted hazard ratio 0.19 compared with no contact lens).[10] That is an association in records, not proof that the lenses prevented surgery.
- The EBAA relates the long decline in US keratoconus transplants to cross-linking and improved rigid and scleral lens fitting.[1] In the Netherlands, about 25% fewer keratoconus transplants were performed in the three years after cross-linking was introduced than in the three years before.[8]
For a side-by-side look at the two options, see scleral lenses vs a corneal transplant.
After a transplant: vision and who keeps wearing them
A transplant can leave the cornea clear but irregular, and glasses often can’t fix the blur. A 2025 systematic review pooled 15 studies (13 case series and 2 chart reviews) with 464 eyes fitted with contact lenses after a transplant, 97% of them after full-thickness surgery. Scleral lenses were the most common lens type, fitted in 285 eyes (61%). Every study reported a significant improvement in vision, and most people could wear their lenses comfortably for 8 to 12 hours a day.[11]
Vision
| Study | Who | Design | Vision with scleral lenses[13][12][14][15] |
|---|---|---|---|
| US (UC Davis), 2016 | 48 eyes of 34 people after PK | Retrospective | 44 eyes (91.7%) reached 20/40 or better; average gain of two lines over prior glasses or contact lenses |
| Israel, 2014 | 31 people after PK; mean astigmatism 8.0 D, mean steepest keratometry 55.0 D | Retrospective | 23 people (reported as 82%) reached decimal 0.5 (about 20/40) or better |
| Iran, 2015 | 56 eyes of 45 people after PK or DALK | Prospective | 0.73 logMAR in glasses → 0.17 with mini-scleral lenses |
| Brazil, 2017 | 27 eyes of 21 people after PK | Retrospective | Average 0.09 logMAR |
Sources: US[13], Israel[12], Iran[14], Brazil[15].
Grafts are often decades old when people are fitted. In the Israeli series, the gap between surgery and fitting ranged from 0.7 to 36 years, and grafts 20 years or older needed refitting more often because of recurring ectasia (the original thinning coming back).[12]
Comfort and how transplants compare
- In a US PROSE series of 90 eyes with irregular corneas, people with astigmatism after PK had the largest improvement in symptom and function scores (OSDI), 79%.[16]
- In a 2026 prospective study from China comparing groups, vision improved in every group, but the post-transplant group gained the least and reported lower comfort than the keratoconus group.[17]
- In a retrospective series of irregular corneas, success measured by wearing time was significantly higher in keratoconus than in post-transplant eyes.[18]
Who keeps wearing them
| Study | Stopped wearing[13][14][15][12] | Notes |
|---|---|---|
| US, 48 eyes | 19 eyes (39.5%) | Most common reason: insertion and removal (8 of the 19) |
| Iran, 56 eyes | 23 eyes ordered lenses; 14 were still wearing at about 22 months | Barriers to ordering: cost and handling |
| Brazil, 27 eyes | 4 eyes | |
| Israel, 31 people | 28 still wearing at last follow-up | Follow-up 6 months to 8.8 years; mean 5.2 years |
Sources: US[13], Iran[14], Brazil[15], Israel[12].
Across the systematic review, dropout ranged from 0% to 39%, mainly because of lens intolerance, discomfort, and graft rejection.[11] In the US study, people who kept wearing their lenses were more likely to describe their vision as good, even though measured vision gains were similar to those who stopped.[13]
Risks to the graft
Swelling
The cornea’s inner layer, the endothelium, pumps fluid out to keep it clear. Transplants have fewer of these cells, and a scleral lens slightly reduces oxygen, so grafts can swell more during wear.
- About three times the swelling of healthy corneas. In 9 eyes after PK wearing high-oxygen (Dk 100), non-fenestrated scleral lenses for an average of 6.2 hours, central swelling averaged 2.99%, with more toward the lower graft edge. The authors cite 1 to 2% in healthy corneas under similar conditions.[19]
- More swelling in older grafts and full-thickness grafts. In 12 grafted eyes after 8 hours of wear, average swelling was 7.2%. It was closely linked to graft age (r = 0.80), not to baseline cell measurements, and was greater after PK than DALK (11.38% vs 5.23%), though the PK grafts were older. Apparent drops in cell counts right after removal may have been an imaging artifact from the swelling rather than real cell loss.[20]
- Lens size may matter. In a three-center study of 31 eyes at least 5 years after PK (90% had keratoconus before surgery), cell density averaged 780 cells/mm², and lens-wearing eyes swelled 1.9% on average over 6 to 8 hours. Corneal rigid lenses and large scleral lenses caused more swelling than no lens, but smaller scleral lenses did not. All grafts stayed clear. Lower cell density was only weakly linked to more swelling (r = -0.39), and the authors concluded cell count is not a robust predictor.[21]
- Sudden swelling in very old grafts. Three case reports describe sudden, painful swelling suggestive of hydrops in scleral wearers whose transplants for keratoconus were 33 to 35 years old, with recurring ectasia. Similar events happen in old grafts without lenses, but two of the three occurred 3 days and 4 months after a refit, which the authors noted suggests some association.[22]
Rejection and infection
| Study | Rejection episodes[12][13][15] | Infection (microbial keratitis) |
|---|---|---|
| Israel, mean 5.2 years | 30.0% of eyes had at least one | 2 eyes (6%) |
| US | 6 eyes (12.5%); 3 resumed lens wear | None |
| Brazil | None observed | 1 eye |
Sources: Israel[12], US[13], Brazil[15].
Across the systematic review, the most reported complications were graft rejection (18 eyes), redness of the conjunctiva (8), surface injury (5), graft swelling (4), and infection (3), out of 464 eyes.[11] A separate case series describes three infections in scleral wearers with grafts who also had dry eye or exposure and were on immune-suppressing medicines; the authors concluded several factors, the lens among them, may have contributed, and recommend close monitoring.[23]
None of these studies can tell you whether lens wear raised or lowered the rejection rate, because none had a comparison group. Grafts carry a rejection risk of their own, and a scleral lens corrects vision; it doesn’t protect the graft from rejection or from the slow loss of inner-layer cells.
How to read these numbers
Transplant counts. The EBAA counts tissue by where it was used. About 31.1% of tissue recovered in the US in 2024 was exported to surgeons abroad, and the EBAA analyzes reasons for surgery only for US transplants, because most exported tissue (64% for full-thickness grafts) comes with no diagnosis.[1] Even US diagnoses are incomplete: see the “unknown or not reported” row above. Be careful with 2020 figures: COVID-19 cut donor corneas and transplants by about 20% that year.[2]
Scleral lens studies. Almost all of the data come from full-thickness transplants; results may differ after partial-thickness transplants such as DALK or DMEK. The designs are mostly retrospective case series from one clinic, with a few dozen people each, and follow-up is mostly a few years. None compared lens wearers with similar grafts that had no lens, which is the comparison needed to know whether a lens changes the risk of rejection or graft failure. Vision is reported in logMAR (lower is better), Snellen fractions such as 20/40, or decimal acuity (higher is better; 1.0 equals 20/20).
So this research can’t yet tell you whether scleral lenses change a graft’s rejection or failure risk, how they perform after partial-thickness transplants, or what happens to graft survival over decades of wear.
For eye doctors
Irregular and high astigmatism after a clear graft is a common reason for referral. Fit only once the corneal surgeon considers the graft stable, and monitor edema and rejection jointly. More on edema monitoring is in monitoring corneal edema in scleral wearers.
Endothelial reserve and lens design
A review gives typical adult cell density as 2,000 to 2,500 cells/mm², with decompensation once counts fall below about 500 to 1,000 cells/mm². It recommends close monitoring for edema and rejection, considering baseline and follow-up pachymetry and specular microscopy, and modifying the fit if swelling appears: reducing sagittal depth, flattening the landing profile, increasing Dk, shortening wear time, or fenestrating.[25] As the swelling studies above show, no validated cell density cutoff exists, and lens design (diameter, clearance, Dk, fenestration) is the main lever for limiting hypoxic and mechanical stress.
- Fenestration. Adding three 1 mm limbal fenestrations cut central edema by 39% on average in 20 healthy young adults after 3 hours of wear. It has not yet been tested in graft populations.[26]
- Trial-lens challenge. Tomography before and after wearing a trial lens can help separate lens-induced hypoxic swelling from intrinsic endothelial failure, which decides whether the patient needs a refit or surgery.[27]
Co-management in practice
Before referral, send: graft type and date, surgeon, indication, suture status, rejection history and treatment, current steroid regimen, any specular microscopy and pachymetry, and serial topography. See the referral checklist and co-managing scleral lens patients.
Ask the fitter for: lens diameter, material Dk, clearance, any fenestration, and pre- and post-wear pachymetry.
Between visits, watch for:
- new stromal or epithelial edema, or a rise in pachymetry
- signs of rejection: keratic precipitates, an endothelial rejection line, stromal edema, anterior chamber reaction, or new injection
- infiltrates, particularly in patients on immunosuppression or with surface disease
- recurrent ectasia at the host-graft junction
Make sure patients with grafts know the graft rejection warning signs their surgeon has described and that they should remove the lens and call the surgeon the same day if they occur.
Common questions
How many corneal transplants are done in the US each year, and why?
The Eye Bank Association of America reported 49,427 full-thickness, front-layer, and back-layer transplants performed in the US with US eye bank tissue in 2024. The most common reason was failure of the cornea's inner (endothelial) layer, at 63.0% of US transplants; Fuchs' dystrophy alone was 35.2%.
How long does a corneal transplant last?
It varies by reason for the graft and by type. In the Australian Corneal Graft Registry, the chance a full-thickness graft was still working was 0.87 at 1 year, 0.73 at 5 years, 0.60 at 10 years, and 0.46 at 15 years. Grafts for keratoconus tend to last longer: in a Japanese series, 93.2% were still working at 25 years.
Can I wear scleral lenses after a corneal transplant?
Many people do. In a 2025 systematic review of 464 eyes fitted with contact lenses after a transplant, scleral lenses were the most common type, and every included study reported better vision with lenses. Grafted corneas can swell more under a scleral lens, so whether they suit your graft is a decision for your fitter and cornea surgeon together.
How long after a transplant can I be fitted?
That is your surgeon's call, based on healing and stitches. The studies here fitted people anywhere from under a year to decades after surgery; in one series, the gap ranged from 0.7 to 36 years.
Can a scleral lens cause my graft to reject?
The evidence can't say. Rejection episodes are reported in scleral lens wearers with grafts: 30.0% of eyes over about five years in one series, and 12.5% in another. Grafts can reject without a lens, and neither study had a comparison group of grafts without lenses. Your surgeon can tell you your graft's baseline risk.
Do scleral lenses work as well after a transplant as for keratoconus?
Vision gains are usually good, but in a 2026 prospective study comparing groups, people with transplants gained the least vision and reported lower comfort than people with keratoconus.
Can scleral lenses help avoid a transplant in keratoconus?
For some people. At a Belgian clinic, 40 of 51 eyes with severe keratoconus prescribed scleral lenses instead of surgery were still wearing them after about two and a half years. US transplants for keratoconus have declined over time, which the Eye Bank Association of America relates to cross-linking and improved lens fitting.
Is there an endothelial cell density below which scleral lenses should not be fitted?
No validated cutoff exists. A review cites decompensation below about 500 to 1,000 cells/mm², and lower central density correlated with more swelling in one study, but the authors concluded cell density was not a robust predictor of lens-induced swelling. A trial-lens challenge with pre- and post-wear measurements is more informative.