Oman Journal of Ophthalmology

: 2021  |  Volume : 14  |  Issue : 3  |  Page : 144--148

Indications for penetrating keratoplasty in Iranian patients

Mojtaba Eidizadeh, Leila Ebadi-Soflou, Aashkan Safarzadeh Khoushabi 
 Department of Opthalmology, Imam Khomeini Hospital, Kermanshah University of Medical Sciences and Health Services, Kermanshah, Iran

Correspondence Address:
Dr. Aashkan Safarzadeh Khoushabi
Imam Khomeini Hospital, Kermanshah University of Medical Sciences and Health Services, Kermanshah


BACKGROUND: The outcome of penetration into keratoplasty (PK) related to corneal disease is responsible for corneal blindness. The aim of this study is to evaluate the indications and visual outcome of PK in Imam Khomeini Hospital in Kermanshah from March 2017 to March 2019. MATERIALS AND METHODS: Data were reviewed from the medical records of 115 PK done in the Department of Ophthalmology, Imam Khomeini Hospital, Kermanshah, from March 2017 to March 2019. Data analysis done using paired Student's t-test for hypothesis testing of grouped values of preoperative and the last follow-up best-corrected visual acuity in cases of optical and therapeutic grafts. P <0.05 was considered statistically significant. RESULTS: In this study, the data of 115 eyes of 108 patients were reviewed. The most common indication for keratoplasty was corneal scarring including adherent leucoma, 34 (29.56%). Therapeutic keratoplasty was done for 26 patients. One case of tectonic graft was included in therapeutic keratoplasty group for analysis. There was statistically significant difference (P = 0.0001) in best-corrected visual acuity improvement from 1.36 logMAR + 0.024 (standard deviation [SD]) preoperatively to 0.357 logMAR + 0.42 (SD) postoperatively and 1.4 logMAR + 0.000 (SD) preoperatively to 0.15 logMAR + 0.55 (SD) postoperatively for optical and therapeutic grafts, respectively. CONCLUSION: Active or treated infectious keratitis was one of the most important indications for keratoplasty. Symptoms of poor prognosis were more pronounced in this part of the country. Patients' vision after corneal transplantation was encouraging, especially in cases of optical keratoplasty.

How to cite this article:
Eidizadeh M, Ebadi-Soflou L, Khoushabi AS. Indications for penetrating keratoplasty in Iranian patients.Oman J Ophthalmol 2021;14:144-148

How to cite this URL:
Eidizadeh M, Ebadi-Soflou L, Khoushabi AS. Indications for penetrating keratoplasty in Iranian patients. Oman J Ophthalmol [serial online] 2021 [cited 2022 Aug 12 ];14:144-148
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Full Text


Although corneal opacity is a common cause of visual loss in developing countries, access to sight restoring corneal transplantation remains challenging for many patients.[1] In poor health-care systems, penetrating keratoplasty management is complicated by a lack of supportive infrastructure such as eye banks, operating rooms, and up-to-date equipment.

There may also be limited access to trained corneal surgeons and follow-up care and little opportunity for corrective lenses for visual rehabilitation.[2],[3]

Keratoplasty is the only way to restore vision in corneal blindness, and its success rate in developing countries (46.5%) is lower than that in developed countries.[4] There are numerous reports of signs of penetration into keratoplasty (PK) in developed and developing countries. Signs of corneal transplantation with poor prognosis for transplant survival are more common in Iran than in the developed world.[5],[6]

In developing countries, corneal disease is the major cause of visual impairment and blindness. Various infectious and inflammatory conditions cause corneal opacity and blindness. This imposes many problems on the health-care systems of the countries. The most common pathogens in active infectious keratitis are staph epidermidis, staph aureus, and fungal infections.[7]

The data available in 2000 suggest that there are approximately 50 million blind people in the world.[8] Currently, PK is done on 100 large and small ophthalmology centers in Iran. Tissue requirements for PK and similar methods have been proposed by one institution called, “The Central Eye Bank of Iran IR located in Capital, Tehran.”

This study is important in that it has not yet been evaluated in the Western part of the country, and complications of keratitis are also very common due to the late referral of patients to hospitals. With the increase in the number of corneal surgeons in Iran and increased PK levels in patients with corneal blindness, we did a retrospective study conducted to identify indications for corneal transplant surgery.

 Materials and Methods

This retrospective study compiled and reviewed the eye bank records of patients who had undergone corneal grafting in Imam Khomeini Hospital in Kermanshah from March 2017 to March 2019. The study was approved by the Ethics Committee of Kermanshah University of Medical Sciences (IR.KUMS.1398.1013).

Patient data including gender and age, surgical techniques, and indications for keratoplasty were retrieved. The absolute and relative frequencies and percentages were provided for each indication and surgical technique. All patients with these criteria were included in the study during this period.

Patients were divided into three age groups: 0–20, 20–49, and 50–50 years, and they were examined for corneal transplant criteria. PK symptoms were divided into 8 diagnoses.

Best-corrected visual acuity (BCVA) with pinhole, glasses, and rigid gas permeable lenses for high astigmatism, intraocular pressure, and graft clarity were recorded postoperative 1, 3, and 6 months and 1 year period for all patients. One-year follow-up was considered as the last follow-up. The records were reviewed for age, sex, preoperative diagnosis, and preoperative BCVA. Surgical details were noted in terms of grades of the graft used, and any additional procedures such as cataract surgery, trabeculectomy, intraocular lens (IOL) explantation, triple procedure, vitrectomy, and goniosynechialysis were recorded.

Outcomes were evaluated in terms of infection cure rate in therapeutic grafts, graft clarity, and final BCVA for optical grafts. Complications if any were noted for all cases. Graft rejection was considered mild if there were 1–5 keratic precipitates (KPs), subepithelial infiltrates, and increased corneal thickness without anterior chamber reaction and severe if >5 KPs with stromal infiltrates, endothelial rejection line, and increased corneal thickness with anterior chamber reaction. Graft clarity was Grade 4 if clear view of iris details was possible, Grade 2–3 without good view of iris details, and Grade 1–0 for opaque graft with no or poor view of anterior chamber details.[9],[10] Graft failure was defined as irreversible loss of graft clarity with rejection episode for 3 months or more. BCVA were converted from the Snellen units to the logarithm of minimal angle of resolution (logMAR).

SPSS software (version 22; SPSS, Inc., Chicago, IL, USA) was used for data analysis. Paired Student's t-test was used for hypothesis testing of grouped values of preoperative and the last follow-up BCVA in cases of optical and therapeutic grafts. P <0.05 was considered statistically significant.


In the present study, 115 eyes from 108 patients were examined, three of which were reconstructive and one was bilateral. The age at which PK was performed varied from 20 to 20 years (mean 50.34 years, SD 17.45 years). In this study, men and women were 75 (65.21%) and 40 (34.78%), respectively. The highest age group of 77 patients (66.95%) was over 50 years. The right eye was involved in 64 (55.65%) cases.

The most common indication for PK was corneal scarring including adherent leucoma 34 (29.56%) and keratoconus was seen in 4 (3.47%). Corneal dystrophy was seen in 4 (3.47%) cases, with Congenital Hereditary Endothelial Dystrophy in 1 (0.86%) case and stromal dystrophy (2 eyes of granular dystrophy type 1 and one eye of granular dystrophy type II) in 3 (2.60%) [Table 1].{Table 1}

Tectonic PK was performed in 25 cases. Of the 24 cases (20.8%) infected with infectious keratitis, a maximum of 18 (75.75%) were from corneal puncture wounds and 6 cases (25.25%) were non-trimmed corneal wounds that were treated with medication. They did not answer or were punctured. Among the cases of infectious keratitis, 10 (41.6%) bacterial and 5 (16.6%) fungi have been confirmed by fungal histopathological report [Figure 1].{Figure 1}

PK was done for optical reasons in majority of 89 (77.39%) eyes. Plain osteopoikilosis (OPK) and triple procedure were done in 67 (75.28%) and 12 (13.48%), respectively. In 2 (2.24%) cases, IOL was not put because of very high myopia in one case and posterior capsular rent in other case where anterior vitrectomy was done [Table 2].{Table 2}

In all cases underwent OPK, BCVA was preoperative <20/20>, with 81 cases (91/91 ÷ 91) of BCVA <20/400. In the last follow-up, a maximum of 41 (46.06) cases fell to the level of BCVA 20/20–20/200 and 31 (34.83%) BCVA >20.60 [Table 3]. All cases of corneal and keratoconus dystrophy achieving BCVA more than 20/60 by the last follow up. Except one case whom transplantation was not performed. BCVA improved from 1.36 logMAR + 0.024 (SD) before surgery to 0.357 logMAR + 0.42 (SD) after surgery in the last follow-up of one year. Statistically, a significant difference (P = 0.0001, P = 0.89) was observed with an average difference of 1.02.{Table 3}

The degree of transparency of the graft tissue was 72 (62.60%), Grade 3 in 16 (13.91%), and Grade 1 in 16 (13.91%) Grade 4. Eleven patients (56.9%) with glaucoma after keratoplasty surgery (PKP) who were resistant to three anticancer drugs and trabeculectomy with mitomycin C (0.2 mg/ml) were performed to save the transplant in all cases.

One case with pre-existing glucomatous optic atrophy which led to graft failure, Rests (n = 10) survived with good visual outcome (BCVA of 20/60– 20/200). Secondary graft failure occurred in (n = 14, 15.73%) eyes due to infection, ≥2 episodes of severe graft rejection, endothelial failure and glaucoma in 4 (28.57%), 4 (28.57%), 3 (21.42%), and 3 eyes (21.42%), respectively. Out of 4 cases of infection, two cases were recurrent herpetic viral keratitis presented with persistent epithelial defect and graft thinning. Amniotic membrane transplantation was done for these cases to avoid perforation and the goal was achieved but graft got opacified. Five (5.61%) cases had one episode of mild graft rejection and were given methylprednisolone 1 g intravenous stat, followed by oral and topical steroids as well as immunosuppressant like topical cyclosporine (0.05%), and rejection was reversed with clear graft. In two cases, subconjunctival avastin (2.5 mg in 0.1 ml) was given for regression of the graft vascularization ≥2 quadrants.

Therapeutic success

Successful treatment has been defined as the complete elimination of primary infection after keratoplasty with appropriate medical treatment.

For visual acuity and graft clarity assessment, one case of tectonic graft was considered under group of TPK as the donor cornea used was of Grade B. Of the 26 patients, 22 (84.61%) patients achieved therapeutic success maintaining structural integrity as n = 1 underwent evisceration and n = 2 got phthisic. Therapeutic failure was defined as recurrent graft infection despite medical and surgical intervention. Therapeutic failure occurred in 2 (7.69%) cases: in one case, amniotic membrane transplantation was done to avoid graft melting and stabilization of infection was achieved and one eye underwent evisceration. Complications other than reinfection were glaucoma in 4 (15.38%) cases that underwent trabeculectomy, choroidal detachment in one case which resolved later on with oral steroids, and glaucomatous optic atrophy in one case. All cases had BCVA <20/400 at presentation. At the last follow-up, only 2 (7.69%) eyes had BCVA of >20/60 and maximum cases 14 (53.84%) fell in the group of <20/400 [Table 4]. The graft clarity was Grade 4, 3, and 1 in 5 (19.23%), 5 (19.23%), and 16 (61.53%) cases, respectively.{Table 4}

The BCVA improved from 1.4 logMAR + 0.000 (standard deviation [SD]) preoperatively to 0.15 logMAR + 0.0.55 (SD) postoperatively at the last follow-up. There was statistically significant difference (P = 0.0001, n = 26) with the mean difference of 1.13.


PK can repair the vision of blind corneal patients with various corneal pathologies. The outcome depends on the pathology responsible for corneal blindness or visual impairment.[11]

The present study evaluated 115 eye bank records of corneal transplantation procedures performed between 2017 and 2019.

The course of keratoplasty has changed in Iran over the past eight years. The top six indications in our study were KCN, BK, COS, graft failure, corneal dystrophies, and keratitis, which is different from our previous nationwide report,[12] where the top 5 diagnoses were KCN, COS, BK, corneal dystrophies, and graft failure.

Infective keratitis was a common component in both optical and therapeutic grafts as healed and active keratitis in respective grafts. As compared to the present study, the corneal scarring has been reported to be the proportionally less indication in developed world.[12],[13] Bullous keratopathy was the second common indication for PK in the present study of 30 (26.09%) of total indications, which is comparable to other studies.[8],[14] In this study, pseudophakic bullous keratopathy was more common than aphakic bullous keratopathy. Corneal dystrophies and keratoconus formed very small proportion of indications as compared to developed countries, where keratoconus made up higher proportion of the indications for PK ranging from 7.0% to 31% with a median value of 17.1%.[15],[16],[17] Infective keratitis formed the major indication (40.9%) for keratoplasty in Nepal,[15] which is very high as compared to Iranian studies.[12]

The OPK and TPK were done for different indications, but the difference of visual outcome preoperatively and the last follow-up was statistically significant in both indications.[18]

The most common sign of OPK in this study is corneal opacity due to ulcers, which is comparable to the results of other published Iranian studies.[2] Instead, corneal scarring was not a sign of OPK in Western countries, but it was keratoconus.

All cases of corneal dystrophy and keratoconus were there in the group of BCVA of >20/60. In the present study, corneal dystrophy and keratoconus were good prognosis cases as reported by Dandona et al.[19] All four cases of ABK developed glaucoma due to which graft failed in three cases, but one graft could survive due to early trabeculectomy. ABK was one of the worst prognoses in optical grafts as supported by other study.[19]

The success of TPK lies in eradication of the primary infection and salvageability of the globe loss of vision or even eyes may be caused by a variety of infectious or inflammatory diseases. The prognosis is likely to be poor in patients receiving emergency corneal transplantation due to severe infectious keratitis.

Following stabilization of the eye, repeat keratoplasty can be performed on an elective basis for optical purposes. Of the 26 patients, 22 (84.61%) patients achieved therapeutic success maintaining structural integrity and stabilization of the eye, which is comparable to the results of Ti et al.[20] In the present study, only 16 (61.53%) cases regained BCVA >20/200, which is comparable to the results of Ti et al.,[12] where the number of eyes with BCVA >6/60 (20/200) was 58.5%. Graft clarity varied by indications for transplantation as in corneal scarring, infective keratitis, and keratoconus. The graft clarity was comparable to the Indian study by Varghese et al.[21] For bullous keratopathy, graft clarity in the present study was comparable to the studies conducted by Randleman et al. and Zare et al.[22],[23]


There are few limitations to this study, as we did not analyze the donor's details, such as the donor's age, the cause of the donor's death, or the length of time the donor tissue was preserved, which could affect the survival of the transplant.

In cases of corneal dystrophy, the anterior deep lamellar keratoplasty has not been performed due to limited equipment requirements. Assessment of vision results is based on BCVA, but information on astigmatism is not available for the entire series. Due to international sanctions and the resulting problems, some equipment was not available, but surgeons preferred to do penetrating keratoplasty.


In the current study, active or improved wound keratitis is the leading cause of both types of PK with good vision improvement. Infectious keratitis has been common in this part of Iran due to the predominance of farmers.

The data reported in this paper suggest that PK could be a very successful way to visualize the outcome in this part of the developing world for many reasons.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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