This was a retrospective descriptive study based on the analysis of medical records of patients seen in consultation in the Ophthalmology Department of the University Hospital of Brazzaville from 1 July to 31 December 2024.

2.1.1. Inclusion Criteria

Patients under 60 years of agePatients who underwent an etiological work-up for cataractPatients who gave informed consent

2.1.2. Non-Inclusion Criteria

Patients aged 60 years and olderCongenital and infantile cataractsIncomplete records

2.2.1. Ophthalmologic Assessment

Patients underwent:

Assessment of visual acuity using the Monoyer chartSlit-lamp examinationMeasurement of intraocular pressure with Goldmann applanation tonometryFundus examination with a 90-diopter lens

2.2.2. Etiological Work-Up for Cataract

The etiological work-up looked for:

Physicalorchemicaltrauma with or without a foreign bodyOculardiseaseAnterior uveitisAngle-closure glaucomaHigh myopiaChoroidal melanomaIntraocular tumorRetinitis pigmentosaOcular ischemic syndromeGeneraldiseaseDiabetesHypocalcemiaSteinert diseaseFabry diseaseSyndermatotic cataractIatrogeniccauseAfter ocular surgeryFollowing topical or systemic corticosteroid therapyUseofcosmeticsIn particular dermocorticosteroids used for skin lightening

2.2.3. Sampling

We performed exhaustive recruitment from the records of all patients aged 10 to 59 years who consulted during the study period. In cases of bilateral cataract, only the eye with the lower visual acuity was included. Patients were classified according to their preoperative visual acuity using the WHO classification of visual impairment and blindness [5].

Data were entered in Microsoft Office Excel 365 and analyzed using the public health software SPSS (version 24, Chicago, USA).

The frequency of cataract in our study population was 9.3%, and only 16.4% of these cases concerned patients under 60 years of age. The frequency of cataract varies with the age group studied and with each country’s capacity to manage this condition. Cedrone [6], who worked in Italy on subjects aged 45 to 69 years, reported a cataract prevalence of 3.7%; this lower frequency is related to better management capacities for this condition in that developed country. Mahdi in Nigeria, in patients aged 40 years and over, observed a cataract prevalence of 19.8%; this prevalence was 2.5% between 40 and 49 years and 9.2% between 50 and 59 years.

The mean age of patients in our study was 46.97 ± 11.5 years. Verma [3] in India, who worked on presenile cataract, found a mean age of 47.3 years.

The predominant age group (47.9%) was patients aged 50 to 59 years, which was also the oldest age group in the study. Kherdekar [7] in India, who worked on relatively younger subjects, found a majority of patients in the oldest age group of his study, 30 to 40 years, accounting for 74.5% of cases. This illustrates the influence of age even among patients under 60 years.

With a sex ratio of 1.13, there was a slight male predominance. Although female predominance is more commonly reported in the literature [3][7], male predominance has also been found in some studies [8].

The main reason for consultation was decreased visual acuity in 93.3% of cases, followed by diabetes follow-up. Decreased visual acuity is usually the first sign of cataract. In his study, Rajesh [9] found it in 98.6% of cases.

A total of 63% of patients had visual acuity less than 1/10, and 7.6% had visual acuity greater than or equal to 5/10. Jansone-Langina [10] in Latvia reported a mean preoperative visual acuity with correction greater than 5/10, reflecting earlier management.

The most frequent type of cataract in our study was total cataract, with 47.1% of cases, followed by nuclear cataract in 20.2%. Verma [3] reported 64.2% nuclear cataracts followed by cortical cataracts with 21.7% of cases; total cataracts accounted for 5%. Kherdekar [7] found a predominance of posterior subcapsular cataracts with 45% of cases, followed by nuclear cataracts with 26%; white cataract accounted for less than 9% of cases. The high frequency of total cataracts in our study is likely related to the lower economic level in our country and more difficult access to a center providing eye care.

The reported risk factors help to better understand the mechanisms leading to these cataracts.

However, in 53% of cases we did not identify any of the risk factors investigated. In his study, Verma [3] likewise did not identify risk factors in 65.9% of cases. There are factors whose involvement can be suspected but not demonstrated, such as sun exposure already mentioned by Kherdekar [7], or simply age approaching 60 years. In our series, 47.9% of patients were between 50 and 59 years old, suggesting presenile cataract.

Diabetes, a well-known cause of cataract, was found in 26.9% of patients, making it the leading identified cause of cataract before age 60. Kherdekar [7] also reported diabetes as the leading cause of presenile cataract with 48.5% of cases, whereas it ranked second after smoking in the study by Verma [3].

Trauma accounted for 16% of cataract causes. This factor, predominant among younger patients, reflects the impact of accidents often related to occupational or domestic activities. Traumas accounted for 6.9% of cataract causes in the study by Doutetien [11]. This lower frequency in that study is due to the inclusion of all cataracts, not only cataracts in subjects under 60 as in our study.

Uveitis was responsible for 1.7% of cataracts; this result is close to that of Praveen [8], who found 1.2% of cataracts related to uveitis.

Long-term corticosteroid therapy is known for its adverse effects, including corticosteroid-induced cataract; its frequency in our study was 1.7%. A particular aspect of this risk factor in our series was the use of dermocorticosteroids for skin lightening. This risk factor, already reported by Fanny [4] in Côte d’Ivoire, leads to cataract after five to ten years of continuous use of dermocorticosteroids to lighten and maintain a lighter skin tone.

The results of this study highlight the diversity of etiologies of cataracts in patients under 60 years, while emphasizing certain modifiable factors such as diabetes control and reduction of exposure to trauma and harmful substances.

The use of dermocorticosteroids for skin lightening, although not quantified in this study, could be explored further in future work, given its possible impact on ocular structures.